5054935
Facial and semantic emotional interference: A pilot study on the behavioral and cortical responses to the dual valence association task
BackgroundIntegration of compatible or incompatible emotional valence and semantic information is an essential aspect of complex social interactions. A modified version of the Implicit Association Test (IAT) called Dual Valence Association Task (DVAT) was designed in order to measure conflict resolution processing from compatibility/incompatibly of semantic and facial valence. The DVAT involves two emotional valence evaluative tasks which elicits two forms of emotional compatible/incompatible associations (facial and semantic).MethodsBehavioural measures and Event Related Potentials were recorded while participants performed the DVAT.ResultsBehavioural data showed a robust effect that distinguished compatible/incompatible tasks. The effects of valence and contextual association (between facial and semantic stimuli) showed early discrimination in N170 of faces. The LPP component was modulated by the compatibility of the DVAT.ConclusionsResults suggest that DVAT is a robust paradigm for studying the emotional interference effect in the processing of simultaneous information from semantic and facial stimuli.
24502835
Emotion simulation during language comprehension
We report a novel finding on the relation of emotion and language. Covert manipulation of emotional facial posture interacts with sentence valence when measuring the amount of time to judge valence (Experiment 1) and sensibility (Experiment 2) of the sentence. In each case, an emotion-sentence compatibility effect is found: Judgment times are faster when facial posture and sentence valence match than when they mismatch. We interpret the finding using a simulation account; that is, emotional systems contribute to language comprehension much as they do in social interaction. Because the effect was not observed on a lexical decision task using emotion-laden words (Experiment 3), we suggest that the emotion simulation affects comprehension processes beyond initial lexical access.
7840819
Measuring individual differences in implicit cognition: the implicit association test.
An implicit association test (IAT) measures differential association of 2 target concepts with an attribute. The 2 concepts appear in a 2-choice task (2-choice task (e.g., flower vs. insect names), and the attribute in a 2nd task (e.g., pleasant vs. unpleasant words for an evaluation attribute). When instructions oblige highly associated categories (e.g., flower + pleasant) to share a response key, performance is faster than when less associated categories (e.g., insect & pleasant) share a key. This performance difference implicitly measures differential association of the 2 concepts with the attribute. In 3 experiments, the IAT was sensitive to (a) near-universal evaluative differences (e.g., flower vs. insect), (b) expected individual differences in evaluative associations (Japanese + pleasant vs. Korean + pleasant for Japanese vs. Korean subjects), and (c) consciously disavowed evaluative differences (Black + pleasant vs. White + pleasant for self-described unprejudiced White subjects).
6835241
Implicit measures: A normative analysis and review.
Implicit measures can be defined as outcomes of measurement procedures that are caused in an automatic manner by psychological attributes. To establish that a measurement outcome is an implicit measure, one should examine (a) whether the outcome is causally produced by the psychological attribute it was designed to measure, (b) the nature of the processes by which the attribute causes the outcome, and (c) whether these processes operate automatically. This normative analysis provides a heuristic framework for organizing past and future research on implicit measures. The authors illustrate the heuristic function of their framework by using it to review past research on the 2 implicit measures that are currently most popular: effects in implicit association tests and affective priming tasks. (PsycINFO Database Record (c) 2009 APA, all rights reserved).
17691210
Electrophysiological Studies of Face Perception in Humans
Event-related potentials (ERPs) associated with face perception were recorded with scalp electrodes from normal volunteers. Subjects performed a visual target detection task in which they mentally counted the number of occurrences of pictorial stimuli from a designated category such as butterflies. In separate experiments, target stimuli were embedded within a series of other stimuli including unfamiliar human faces and isolated face components, inverted faces, distorted faces, animal faces, and other nonface stimuli. Human faces evoked a negative potential at 172 msec (N170), which was absent from the ERPs elicited by other animate and inanimate nonface stimuli. N170 was largest over the posterior temporal scalp and was larger over the right than the left hemisphere. N170 was delayed when faces were presented upside-down, but its amplitude did not change. When presented in isolation, eyes elicited an N170 that was significantly larger than that elicited by whole faces, while noses and lips elicited small negative ERPs about 50 msec later than N170. Distorted human faces, in which the locations of inner face components were altered, elicited an N170 similar in amplitude to that elicited by normal faces. However, faces of animals, human hands, cars, and items of furniture did not evoke N170. N170 may reflect the operation of a neural mechanism tuned to detect (as opposed to identify) human faces, similar to the structural encoder suggested by Bruce and Young (1986). A similar function has been proposed for the face-selective N200 ERP recorded from the middle fusiform and posterior inferior temporal gyri using subdural electrodes in humans (Allison, McCarthy, Nobre, Puce, & Belger, 1994c). However, the differential sensitivity of N170 to eyes in isolation suggests that N170 may reflect the activation of an eye-sensitive region of cortex. The voltage distribution of N170 over the scalp is consistent with a neural generator located in the occipitotemporal sulcus lateral to the fusiform/inferior temporal region that generates N200.
34009900
The face-sensitive N170 and VPP components manifest the same brain processes: The effect of reference electrode site
OBJECTIVE
(1) To investigate the hypothesis that the vertex positive potential (VPP) and the N170 ERP components reported in the face processing literature are two manifestations of the same brain processes whose relative amplitude in a given experiment is dependent on reference electrode; (2) to investigate whether differences in face/object results reported in studies looking at the VPP and N170 are attributable to the location of reference.


METHODS
EEG was recorded from 53 scalp electrodes referenced online to the left mastoid while subjects viewed face, car and word stimuli. Off-line, the data were systematically re-referenced to the common average, averaged mastoids, averaged earlobes, non-cephalic, and nose. The correlation of timing, amplitude, and effects was investigated across reference electrodes.


RESULTS
(1) The amplitude of the N170 and VPP components varies in a precisely inverse manner across reference; (2) the peaks of the N170 and VPP are temporally coincident for all reference electrodes, (3) both components can be accounted for by the same dipolar configuration, and (4) the components show identical functional properties.


CONCLUSIONS
The VPP and N170 are two 'faces' of the same brain generators.


SIGNIFICANCE
The differential N170/VPP effects observed in ERP studies can be accounted for by differences in reference methodology.
31693565
Event-Related Potentials for Category-Specific Information During Passive Viewing of Faces and Objects
Normal subjects passively viewed an upright or inverted face or objects during recording of event-related potentials. Face inversion augmented N170 amplitude and latency in the temporal region, but on ly the latency in the parietal region. The same manipulation slowed down the on set of the P220 and caused disappearance of the N300, whereas none of these effects was seen after object inversion. Item-specific processing of objects was observed, namely disappearance of the N190 and the appearance of a P170 wave in the left posterior hemisphere to on e object but not the other. These results are concordant with the hypothesis of category-specific processing during the recognition of faces and objects.
1743543
The N170 occipito‐temporal component is delayed and enhanced to inverted faces but not to inverted objects: an electrophysiological account of face‐specific processes in the human brain
Behavioral studies have shown that picture-plane inversion impacts face and object recognition differently, thereby suggesting face-specific processing mechanisms in the human brain. Here we used event-related potentials to investigate the time course of this behavioral inversion effect in both faces and novel objects. ERPs were recorded for 14 subjects presented with upright and inverted visual categories, including human faces and novel objects (Greebles). A N170 was obtained for all categories of stimuli, including Greebles. However, only inverted faces delayed and enhanced N170 (bilaterally). These observations indicate that the N170 is not specific to faces, as has been previously claimed. In addition, the amplitude difference between faces and objects does not reflect face-specific mechanisms since it can be smaller than between non-face object categories. There do exist some early differences in the time-course of categorization for faces and non-faces across inversion. This may be attributed either to stimulus category per se (e.g. face-specific mechanisms) or to differences in the level of expertise between these categories.
15020767
A defense of the subordinate-level expertise account for the N170 component
A recent paper in this journal reports two event-related potential (ERP) experiments interpreted as supporting the domain specificity of the visual mechanisms implicated in processing faces (Cognition 83 (2002) 1). The authors argue that because a large neurophysiological response to faces (N170) is less influenced by the task than the response to objects, and because the response for human faces extends to ape faces (for which we are not expert), we should reject the hypothesis that the face-sensitivity reflected by the N170 can be accounted for by the subordinate-level expertise model of object recognition (Nature Neuroscience 3 (2000) 764). In this commentary, we question this conclusion based on some of our own ERP work on expert object recognition as well as the work of others.
25834267
Mapping event-related brain potential microstates to sentence endings
SummaryWe analyzed topography and strength of 20 channel event-related potential maps to sentence endings differing in correctness, verbal vs. nonverbal surface form, priming, and repetition count. Seventeen healthy subjects silently read correct and incorrect versions of simple sentences with predictable color endings, and of more complex sentences with predictable composite word endings. Color endings appeared in verbal and nonverbal form. Measures of map topography (centroids of the positive and negative areas of the average referenced maps) and strength (Global Field Power) were analyzed. Adaptive segmentation distinguished a pre-N400 and a N400 microstate in the N400 time range. Topography differed between these two microstates, between verbal and nonverbal endings, and between correct color, incorrect color, and incorrect noncolor words. All verbal endings evoked left-lateralized negativity and right lateralized positivity in the pre-N400 microstates. Correct verbal endings evoked consistent posterior positivity and anterior negativity with left-lateralized gradient strength suggesting language-specific processing. New, incorrect noncolor words evoked reversed anterior-posterior N400 and pre-N400 map topographies with more anterior positivity and more posterior negativity than correct colors in each subject. Gradient strength and current source density maps also differed from those to correct colors. Strongest gradients were left-posterior in the pre-N400 but anterior in the N400 microstate, consistent with anterior activity contributing to the posterior N400 negativity. Incorrect and correct colors, which were semantically primed and repeated, showed smaller topographic differences and N400 effects with a different topography. These different maps can not arise by modulation of a single pattern of neural activity and show that the N400 time range consists of multiple distinct microstates.
6844697
Early lateralization and orientation tuning for face, word, and object processing in the visual cortex
Event-related potential (ERP) studies of the human brain have shown that object categories can be reliably distinguished as early as 130-170 ms on the surface of occipito-temporal cortex, peaking at the level of the N170 component. Consistent with this finding, neuropsychological and neuroimaging studies suggest major functional distinctions within the human object recognition system, particularly in hemispheric advantage, between the processing of words (left), faces (right), and objects (bilateral). Given these observations, our aim was to (1) characterize the differential response properties of the N170 to pictures of faces, objects, and words across hemispheres; and (2) test whether an effect of inversion for highly familiar and monooriented nonface stimuli such as printed words can be observed at the level of the N170. Scalp EEG (53 channels) was recorded in 15 subjects performing an orientation decision task with pictures of faces, words, and cars presented upright or inverted. All three categories elicited at the same latency a robust N170 component associated with a positive counterpart at centro-frontal sites (vertex-positive potential, VPP). While there were minor amplitude differences at the level of the occipital medial P1 between linguistic and nonlinguistic categories, scalp topographies and source analyses indicated strong hemispheric and orientation effects starting at the level of the N170, which was right lateralized for faces, smaller and bilateral for cars, and as large for printed words in the left hemisphere as for faces. The entire N170/VPP complex was accounted for by two dipolar sources located in the lateral inferior occipital cortex/posterior fusiform gyrus. These two locations were roughly equivalent across conditions but differed in strength and lateralization. Inversion delayed the N170 (and VPP) response for all categories, with an increasing delay for cars, words, and faces, respectively, as suggested by source modeling analysis. Such results show that early processes in object recognition respond to category-specific visual information, and are associated with strong lateralization and orientation bias.
207698264
ERP Manifestations of Processing Printed Words at Different Psycholinguistic Levels: Time Course and Scalp Distribution
The aim of the present study was to examine the time course and scalp distribution of electrophysiological manifestations of the visual word recognition mechanism. Event-related potentials (ERPs) elicited by visually presented lists of words were recorded while subjects were involved in a series of oddball tasks. The distinction between the designated target and nontarget stimuli was manipulated to induce a different level of processing in each session (visual, phonological/phonetic, phonological/lexical, and semantic). The ERPs of main interest in this study were those elicited by nontarget stimuli. In the visual task the targets were twice as big as the nontargets. Words, pseudowords, strings of consonants, strings of alphanumeric symbols, and strings of forms elicited a sharp negative peak at 170 msec (N170); their distribution was limited to the occipito-temporal sites. For the left hemisphere electrode sites, the N170 was larger for orthographic than for nonorthographic stimuli and vice versa for the right hemisphere. The ERPs elicited by all orthographic stimuli formed a clearly distinct cluster that was different from the ERPs elicited by nonorthographic stimuli. In the phonological/phonetic decision task the targets were words and pseudowords rhyming with the French word vitrail, whereas the nontargets were words, pseudowords, and strings of consonants that did not rhyme with vitrail. The most conspicuous potential was a negative peak at 320 msec, which was similarly elicited by pronounceable stimuli but not by nonpronounceable stimuli. The N320 was bilaterally distributed over the middle temporal lobe and was significantly larger over the left than over the right hemisphere. In the phonological/lexical processing task we compared the ERPs elicited by strings of consonants (among which words were selected), pseudowords (among which words were selected), and by words (among which pseudowords were selected). The most conspicuous potential in these tasks was a negative potential peaking at 350 msec (N350) elicited by phonologically legal but not by phonologically illegal stimuli. The distribution of the N350 was similar to that of the N320, but it was broader and including temporo-parietal areas that were not activated in the rhyme task. Finally, in the semantic task the targets were abstract words, and the nontargets were concrete words, pseudowords, and strings of consonants. The negative potential in this task peaked at 450 msec. Unlike the lexical decision, the negative peak in this task significantly distinguished not only between phonologically legal and illegal words but also between meaningful (words) and meaningless (pseudowords) phonologically legal structures. The distribution of the N450 included the areas activated in the lexical decision task but also areas in the fronto-central regions. The present data corroborated the functional neuro-anatomy of word recognition systems suggested by other neuroimaging methods and described their timecourse, supporting a cascade-type process that involves different but interconnected neural modules, each responsible for a different level of processing word-related information.
900183
Early processing of the six basic facial emotional expressions.
Facial emotions represent an important part of non-verbal communication used in everyday life. Recent studies on emotional processing have implicated differing brain regions for different emotions, but little has been determined on the timing of this processing. Here we presented a large number of unfamiliar faces expressing the six basic emotions, plus neutral faces, to 26 young adults while recording event-related potentials (ERPs). Subjects were naive with respect to the specific questions investigated; it was an implicit emotional task. ERPs showed global effects of emotion from 90 ms (P1), while latency and amplitude differences among emotional expressions were seen from 140 ms (N170 component). Positive emotions evoked N170 significantly earlier than negative emotions and the amplitude of N170 evoked by fearful faces was larger than neutral or surprised faces. At longer latencies (330-420 ms) at fronto-central sites, we also found a different pattern of effects among emotions. Localization analyses confirmed the superior and middle-temporal regions for early processing of facial expressions; the negative emotions elicited later, distinctive activations. The data support a model of automatic, rapid processing of emotional expressions.
14495289
The face-specific N170 component is modulated by emotional facial expression
BackgroundAccording to the traditional two-stage model of face processing, the face-specific N170 event-related potential (ERP) is linked to structural encoding of face stimuli, whereas later ERP components are thought to reflect processing of facial affect. This view has recently been challenged by reports of N170 modulations by emotional facial expression. This study examines the time-course and topography of the influence of emotional expression on the N170 response to faces.MethodsDense-array ERPs were recorded in response to a set (n = 16) of fear and neutral faces. Stimuli were normalized on dimensions of shape, size and luminance contrast distribution. To minimize task effects related to facial or emotional processing, facial stimuli were irrelevant to a primary task of learning associative pairings between a subsequently presented visual character and a spoken word.ResultsN170 to faces showed a strong modulation by emotional facial expression. A split half analysis demonstrates that this effect was significant both early and late in the experiment and was therefore not associated with only the initial exposures of these stimuli, demonstrating a form of robustness against habituation. The effect of emotional modulation of the N170 to faces did not show significant interaction with the gender of the face stimulus, or hemisphere of recording sites. Subtracting the fear versus neutral topography provided a topography that itself was highly similar to the face N170.ConclusionThe face N170 response can be influenced by emotional expressions contained within facial stimuli. The topography of this effect is consistent with the notion that fear stimuli exaggerates the N170 response itself. This finding stands in contrast to previous models suggesting that N170 processes linked to structural analysis of faces precede analysis of emotional expression, and instead may reflect early top-down modulation from neural systems involved in rapid emotional processing.
22854103
Affective judgments of faces modulate early activity (approximately 160 ms) within the fusiform gyri.
Functional neuroimaging studies have implicated the fusiform gyri (FG) in structural encoding of faces, while event-related potential (ERP) and magnetoencephalography studies have shown that such encoding occurs approximately 170 ms poststimulus. Behavioral and functional neuroimaging studies suggest that processes involved in face recognition may be strongly modulated by socially relevant information conveyed by faces. To test the hypothesis that affective information indeed modulates early stages of face processing, ERPs were recorded to individually assessed liked, neutral, and disliked faces and checkerboard-reversal stimuli. At the N170 latency, the cortical three-dimensional distribution of current density was computed in stereotactic space using a tomographic source localization technique. Mean activity was extracted from the FG, defined by structure-probability maps, and a meta-cluster delineated by the coordinates of the voxel with the strongest face-sensitive response from five published functional magnetic resonance imaging studies. In the FG, approximately 160 ms poststimulus, liked faces elicited stronger activation than disliked and neutral faces and checkerboard-reversal stimuli. Further, confirming recent results, affect-modulated brain electrical activity started very early in the human brain (approximately 112 ms). These findings suggest that affective features conveyed by faces modulate structural face encoding. Behavioral results from an independent study revealed that the stimuli were not biased toward particular facial expressions and confirmed that liked faces were rated as more attractive. Increased FG activation for liked faces may thus be interpreted as reflecting enhanced attention due to their saliency.
29213825
Exploring the relationship between vagal tone and event-related potentials in response to an affective picture task
The present study is the first to investigate the relationship between vagal tone level and event-related potentials (ERPs) in adults. Numerous studies have shown a relationship between vagal tone and the individual differences between a variety of psychophysiological, affective, and social outcomes. This suggests that vagal tone can be related to how people process relevant affective social information at the brain level. This study aimed to assess whether the ERP response varies between high and low vagal tone groups, in the face of salient affective information. In the experimental cohort, two groups were separated according to their vagal tone level. ERPs were recorded while individuals performed an affective picture task that included positive, neutral, and negative emotional stimuli. Differences between the high and low vagal tone groups were observed at the early posterior negativity for both positive and negative valences, and at the late positive potential for all the categories. It can be concluded that differences between high and low vagal tone levels are related to differences in the ERPs at early, middle, and late latencies. The results are discussed with respect to the effect of differences between the vagal tone conditions on various stages of information-processing.
12936870
Emotions in word and face processing: Early and late cortical responses
Recent research suggests that emotion effects in word processing resemble those in other stimulus domains such as pictures or faces. The present study aims to provide more direct evidence for this notion by comparing emotion effects in word and face processing in a within-subject design. Event-related brain potentials (ERPs) were recorded as participants made decisions on the lexicality of emotionally positive, negative, and neutral German verbs or pseudowords, and on the integrity of intact happy, angry, and neutral faces or slightly distorted faces. Relative to neutral and negative stimuli both positive verbs and happy faces elicited posterior ERP negativities that were indistinguishable in scalp distribution and resembled the early posterior negativities reported by others. Importantly, these ERP modulations appeared at very different latencies. Therefore, it appears that similar brain systems reflect the decoding of both biological and symbolic emotional signals of positive valence, differing mainly in the speed of meaning access, which is more direct and faster for facial expressions than for words.
22637150
Early and late temporo-spatial effects of contextual interference during perception of facial affect.
Contextual features during recognition of facial affect are assumed to modulate the temporal course of emotional face processing. Here, we simultaneously presented colored backgrounds during valence categorizations of facial expressions. Subjects incidentally learned to perceive negative, neutral and positive expressions within a specific colored context. Subsequently, subjects made fast valence judgments while presented with the same face-color-combinations as in the first run (congruent trials) or with different face-color-combinations (incongruent trials). Incongruent trials induced significantly increased response latencies and significantly decreased performance accuracy. Contextual incongruent information during processing of neutral expressions modulated the P1 and the early posterior negativity (EPN) both localized in occipito-temporal areas. Contextual congruent information during emotional face perception revealed an emotion-related modulation of the P1 for positive expressions and of the N170 and the EPN for negative expressions. Highest amplitude of the N170 was found for negative expressions in a negatively associated context and the N170 amplitude varied with the amount of overall negative information. Incongruent trials with negative expressions elicited a parietal negativity which was localized to superior parietal cortex and which most likely represents a posterior manifestation of the N450 as an indicator of conflict processing. A sustained activation of the late LPP over parietal cortex for all incongruent trials might reflect enhanced engagement with facial expression during task conditions of contextual interference. In conclusion, whereas early components seem to be sensitive to the emotional valence of facial expression in specific contexts, late components seem to subserve interference resolution during emotional face processing.
20060864
Visual processing in a facial emotional context: an ERP study.
Facial emotional processing can be bypassed when faces are task-irrelevant and attention is diverted, although this effect has not been examined when cognitive task occurs within a facial background. Event-related potential (ERP) measures were obtained to evaluate the influence of different irrelevant facial emotional contexts on a simultaneous "ear-size" detection task performance in five processing contexts: (1) neutral face, (2) happy face, (3) fearful face, (4) facial contour, and (5) non-facial context. Reaction times were longer when visual processing occurred in a facial context, regardless of its emotional content. The context of neutral faces also demonstrated a lower number of correct responses, with fewer incorrect responses found during the presentation of fearful faces compared to the neutral facial context. ERP morphology was similar across all conditions, but ERP amplitude from components for the non-facial context was larger than that of the alternative conditions from 100 to 300 ms, with a similar N170-like potential also observed. The findings suggest that simultaneous irrelevant emotional facial stimuli may affect cognitive processing by altering two temporarily overlapped neural mechanisms: one responsible for earlier face detection, and the other involved in emotional recognition. The first might delay simultaneous cognitive actions by diverting attention, whereas while the latter may enhance the availability of processing resources through the participation of a subcortical pathway.
13816083
Recognition of facial expressions is influenced by emotional scene gist
Recognition of facial expressions has traditionally been investigated by presenting facial expressions without any context information. However, we rarely encounter an isolated facial expression; usually, we perceive a persons facial reaction as part of the surrounding context. In the present study, we addressed the question of whether emotional scenes influence the explicit recognition of facial expressions. In three experiments, participants were required to categorize facial expressions (disgust, fear, happiness) that were shown against backgrounds of natural scenes with either a congruent or an incongruent emotional significance. A significant interaction was found between facial expressions and the emotional content of the scenes, showing a response advantage for facial expressions accompanied by congruent scenes. This advantage was robust against increasing task load. Taken together, the results show that the surrounding scene is an important factor in recognizing facial expressions.
20751875
CHRONOMETRY OF VISUAL WORD RECOGNITION DURING PASSIVE AND LEXICAL DECISION TASKS: AN ERP INVESTIGATION
In order to investigate the neuroanatomical chronometry of word processing, two experiments using: Event Related Potentials (ERPs) have been performed. The first one was designed to test the effects of orthographic, phonologic, and lexical properties of linguistic items on the presemantic components of ERPs during a passive reading task and massive repetition used to reduce familiarity effect between words and nonwords. In a second study, the level of familiarity was investigated by varying stimulus repetition and frequency in a lexical decision task. Overall results suggest a functional discrimination between orthographic and nonorthographic stimuli begun as early as 170 ms (N170 component) whereas the next components (N230 and N320) were sensitive to the orthographic nature of the stimuli, but also to their lexical/phonologic proprieties. The N320 associated to phonological processing (Bentin et al., 1999) was modulated by word frequency and massive repetition caused its disappearance. This suggests that this component may reflect a nonobligatory phonologic stage of graphemephoneme conversion postulated by the DRC model (Coltheart et al., 2001) or semantic phonologically mediated pathway (Harm and Seidenberg, in press).
8742572
Early emotion word processing: Evidence from event-related potentials
Behavioral and electrophysiological responses were monitored to 80 controlled sets of emotionally positive, negative, and neutral words presented randomly in a lexical decision paradigm. Half of the words were low frequency and half were high frequency. Behavioral results showed significant effects of frequency and emotion as well as an interaction. Prior research has demonstrated sensitivity to lexical processing in the N1 component of the event-related brain potential (ERP). In this study, the N1 (135-180 ms) showed a significant emotion by frequency interaction. The P1 window (80-120 ms) preceding the N1 as well as post-N1 time windows, including the Early Posterior Negativity (200-300 ms) and P300 (300-450 ms), were examined. The ERP data suggest an early identification of the emotional tone of words leading to differential processing. Specifically, high frequency negative words seem to attract additional cognitive resources. The overall pattern of results is consistent with a time line of word recognition in which semantic analysis, including the evaluation of emotional quality, occurs at an early, lexical stage of processing.
15300183
Attitudes to the right- and left: Frontal ERP asymmetries associated with stimulus valence and processing goals
We used dense-array event-related potentials (ERP) to examine the time course and neural bases of evaluative processing. Participants made good vs. bad (evaluative) and abstract vs. concrete (nonevaluative) judgments of socially relevant concepts (e.g., "murder," "welfare"), and then rated all concepts for goodness and badness. Results revealed a late positive potential (LPP) beginning at about 475 ms post-stimulus and maximal over anterior sites. The LPP was lateralized (higher amplitude and shorter latency) on the right for concepts later rated bad, and on the left for concepts later rated good. Moreover, the degree of lateralization for the amplitude but not the latency was larger when participants were making evaluative judgments than when they were making nonevaluative judgments. These data are consistent with a model in which discrete regions of prefrontal cortex (PFC) are specialized for the evaluative processing of positive and negative stimuli.
39497608
Priming emotional facial expressions as evidenced by event-related brain potentials.
As human faces are important social signals in everyday life, processing of facial affect has recently entered into the focus of neuroscientific research. In the present study, priming of faces showing the same emotional expression was measured with the help of event-related potentials (ERPs) in order to investigate the temporal characteristics of processing facial expressions. Participants classified portraits of unfamiliar persons according to their emotional expression (happy or angry). The portraits were either preceded by the face of a different person expressing the same affect (primed) or the opposite affect (unprimed). ERPs revealed both early and late priming effects, independent of stimulus valence. The early priming effect was characterized by attenuated frontal ERP amplitudes between 100 and 200 ms in response to primed targets. Its dipole sources were localised in the inferior occipitotemporal cortex, possibly related to the detection of expression-specific facial configurations, and in the insular cortex, considered to be involved in affective processes. The late priming effect, an enhancement of the late positive potential (LPP) following unprimed targets, may evidence greater relevance attributed to a change of emotional expressions. Our results (i) point to the view that a change of affect-related facial configuration can be detected very early during face perception and (ii) support previous findings on the amplitude of the late positive potential being rather related to arousal than to the specific valence of an emotional signal.
7915542
The categorization of natural scenes: Brain attention networks revealed by dense sensor ERPs
The present study examined cortical indicators of selective attention underlying categorization based on target features in natural scenes. The primary focus was to determine the neural sources associated with the processing of target stimuli containing animals compared to non-target control stimuli. Neural source estimation techniques [current source density (CSD) and L2-minimum norm estimate (L2-MNE)] were used to determine the sources of the potential fields measured from 58 sensor sites. Assuring an excellent signal-to-noise ratio, the categorization task consisted of 2400 trials. Replicating previous findings, target and non-target ERP activity diverged sharply around 150 ms after stimulus onset and the early differential ERP activity appeared as positive deflection over fronto-central sensor sites and as negative deflection over temporo-occipital regions. Both source estimation techniques (CSD and L2-MNE) suggested primary sources of the early differential ERP activity in posterior, visual-associative brain regions and, although less pronounced, revealed the contribution of additional anterior sources. These findings suggest that selective attention to category-relevant features reflects the interactions between prefrontal and inferior temporal cortex during visual processing of natural scenes.
11281335
Dissociation of event-related potentials indexing arousal and semantic cohesion during emotional word encoding
Event-related potential (ERP) studies have shown that emotional stimuli elicit greater amplitude late positive-polarity potentials (LPPs) than neutral stimuli. This effect has been attributed to arousal, but emotional stimuli are also more semantically coherent than uncategorized neutral stimuli. ERPs were recorded during encoding of positive, negative, uncategorized neutral, and categorized neutral words. Differences in LPP amplitude elicited by emotional versus uncategorized neutral stimuli were evident from 450 to 1000 ms. From 450 to 700 ms, LPP effects at midline and right hemisphere frontal electrodes indexed arousal, whereas LPP effects at left hemisphere centro-parietal electrodes indexed semantic cohesion. This dissociation helps specify the processes underlying emotional stimulus encoding, and suggests the need to control for semantic cohesion in emotional information processing studies.
710356
Contextual blending of ingroup/outgroup face stimuli and word valence: LPP modulation and convergence of measures
BackgroundSeveral event related potential (ERP) studies have investigated the time course of different aspects of evaluative processing in social bias research. Various reports suggest that the late positive potential (LPP) is modulated by basic evaluative processes, and some reports suggest that in-/outgroup relative position affects ERP responses. In order to study possible LPP blending between facial race processing and semantic valence (positive or negative words), we recorded ERPs while indigenous and non-indigenous participants who were matched by age and gender performed an implicit association test (IAT). The task involved categorizing faces (ingroup and outgroup) and words (positive and negative). Since our paradigm implies an evaluative task with positive and negative valence association, a frontal distribution of LPPs similar to that found in previous reports was expected. At the same time, we predicted that LPP valence lateralization would be modulated not only by positive/negative associations but also by particular combinations of valence, face stimuli and participant relative position.ResultsResults showed that, during an IAT, indigenous participants with greater behavioral ingroup bias displayed a frontal LPP that was modulated in terms of complex contextual associations involving ethnic group and valence. The LPP was lateralized to the right for negative valence stimuli and to the left for positive valence stimuli. This valence lateralization was influenced by the combination of valence and membership type relevant to compatibility with prejudice toward a minority. Behavioral data from the IAT and an explicit attitudes questionnaire were used to clarify this finding and showed that ingroup bias plays an important role. Both ingroup favoritism and indigenous/non-indigenous differences were consistently present in the data.ConclusionOur results suggest that frontal LPP is elicited by contextual blending of evaluative judgments of in-/outgroup information and positive vs. negative valence association and confirm recent research relating in-/outgroup ERP modulation and frontal LPP. LPP modulation may cohere with implicit measures of attitudes. The convergence of measures that were observed supports the idea that racial and valence evaluations are strongly influenced by context. This result adds to a growing set of evidence concerning contextual sensitivity of different measures of prejudice.
9639344
Repetition and Event-related Potentials: Distinguishing Early and Late Processes in Affective Picture Perception
A repetition paradigm was used to assess the nature of affective modulation of early and late components of the event-related potential (ERP) during picture viewing. High-density ERPs were measured while participants passively viewed affective or neutral pictures that were repeated up to 90 times each. Both ERP components were modulated by emotional arousal, with ERPs elicited when viewing pleasant and unpleasant pictures different than when viewing neutral pictures. On the other hand, repetition had different effects on these two components. The early occipitotemporal component (150300 msec) primarily showed a decrease in amplitude within a block of repetitions that did not differ as a function of picture content. The late centroparietal component (300600 msec) showed a decrease both between and within blocks of repetitions, with neutral pictures eliciting no late positive potential in the final block of the study. The data suggest that the early ERP primarily reflects obligatory perceptual processing that is facilitated by active short-term memory representations, whereas the late ERP reflects increased resource allocation due to the motivational relevance of affective cues.
42422407
Affective picture processing: An integrative review of ERP findings
The review summarizes and integrates findings from 40 years of event-related potential (ERP) studies using pictures that differ in valence (unpleasant-to-pleasant) and arousal (low-to-high) and that are used to elicit emotional processing. Affective stimulus factors primarily modulate ERP component amplitude, with little change in peak latency observed. Arousal effects are consistently obtained, and generally occur at longer latencies. Valence effects are inconsistently reported at several latency ranges, including very early components. Some affective ERP modulations vary with recording methodology, stimulus factors, as well as task-relevance and emotional state. Affective ERPs have been linked theoretically to attention orientation for unpleasant pictures at earlier components (<300 ms). Enhanced stimulus processing has been associated with memory encoding for arousing pictures of assumed intrinsic motivational relevance, with task-induced differences contributing to emotional reactivity at later components (>300 ms). Theoretical issues, stimulus factors, task demands, and individual differences are discussed.
40258588
Affective ERP processing in a visual oddball task: Arousal, valence, and gender
OBJECTIVE
To assess affective event-related brain potentials (ERPs) using visual pictures that were highly distinct on arousal level/valence category ratings and a response task.


METHODS
Images from the International Affective Pictures System (IAPS) were selected to obtain distinct affective arousal (low, high) and valence (negative, positive) rating levels. The pictures were used as target stimuli in an oddball paradigm, with a visual pattern as the standard stimulus. Participants were instructed to press a button whenever a picture occurred and to ignore the standard. Task performance and response time did not differ across conditions.


RESULTS
High-arousal compared to low-arousal stimuli produced larger amplitudes for the N2, P3, early slow wave, and late slow wave components. Valence amplitude effects were weak overall and originated primarily from the later waveform components and interactions with electrode position. Gender differences were negligible.


CONCLUSION
The findings suggest that arousal level is the primary determinant of affective oddball processing, and valence minimally influences ERP amplitude.


SIGNIFICANCE
Affective processing engages selective attentional mechanisms that are primarily sensitive to the arousal properties of emotional stimuli. The application and nature of task demands are important considerations for interpreting these effects.
29011945
The contributionof task-related factors to ERP repetition effects at short and long lags
Event-related potentials (ERPs) were used to assess the relative contribution of task-related decision-making processes to the repetition effect at Lags 0 and 15. Electrophysiological activity was recorded from 16 subjects in two tasks. Task A required a lexical decision: subjects were instructed to silently count infrequently occurring nonwords in a list of words and nonwords. Task B, a recognition memory task presented in four blocks, required subjects to distinguish between old and new probes in each block. Significant ERP repetition effects, equivalent in both tasks, were found at Lag 0. In contrast, at Lag 15, the repetition effect was significant only in Task A. These results suggest that ERPs are sensitive primarily to poststimulus-identifkation sources of the repetition effect, such as the recovery of episodic traces related to stimulus-categorization and decision-making processes.
15236981
A Structural and Process Analysis of the Implicit Association Test
Abstract The Implicit Association Test (IAT) is based on the observation that participants find it easier to respond in the same way to exemplars of two concepts when these concepts are similar (e.g., “positive” and “flower”) compared to when the concepts are dissimilar (e.g., “positive” and “insect”). In the first part of this article, I argue that the IAT is structurally similar to stimulus–response compatibility tasks. On the basis of this analogy, I then present two response conflict accounts of IAT effects. The data of an experiment that was designed to test these accounts showed that IAT effects reflect attitudes toward the target concepts rather than attitudes toward the individual exemplars of those concepts. The results shed light on the processes that underlie IAT effects, suggest that automatic attitude activation may depend on the construal of the object that is fostered by the context, and clarify the relation between different indirect measures of attitudes.
7497635
Underlying processes in the implicit association test: dissociating salience from associations.
The authors investigated whether effects of the Implicit Association Test (IAT) are influenced by salience asymmetries, independent of associations. Two series of experiments analyzed unique effects of salience by using nonassociated, neutral categories that differed in salience. In a 3rd series, salience asymmetries were manipulated experimentally while holding associations between categories constant. In a 4th series, valent associations of the target categories were manipulated experimentally while holding salience asymmetries constant. Throughout, IAT effects were found to depend on salience asymmetries. Additionally, salience asymmetries between categories were assessed directly with a visual search task to provide an independent criterion of salience asymmetries. Salience asymmetries corresponded to IAT effects and also accounted for common variance in IAT effects and explicit measures of attitudes or the self-concept.
7847407
Consequences of emotional stimuli: age differences on pure and mixed blocks of the emotional Stroop
BackgroundStudies of aging and emotion suggest that older adults show diminished responsiveness to negative information, possibly resulting from increased emotion regulation, but the mechanisms accounting for this effect are uncertain.MethodsTo examine whether aging affects the allocation of attention to negative stimuli, we compared 20 younger and 20 older adults on 2 versions of the emotional Stroop task: "pure blocks," in which all words in each block were either emotional or neutral, and "mixed blocks," a pseudorandomized design in which either a negative emotional or a neutral category word was always followed by six neutral words. The emotional Stroop task typically elicits slower reaction times for naming the font color of negative emotional words compared to neutral, but no studies have examined the effects of aging on the immediate and sustained components of the emotional Stroop effect.ResultsBoth groups showed an emotional Stroop effect on pure blocks manifest as slower RTs on the emotional, relative to the neutral, block. However, only younger adults showed persistent slowing that carried over from emotional words onto subsequent neutral words in mixed blocks.ConclusionThese results suggest that the consequences of emotional stimuli may differ with age. Younger and older adults showed equivalent interference from the emotional words themselves, but older adults did not show a sustained effect of negative information.
9385201
Event-related potential measures of the intending process: Time course and related ERP components
BackgroundThe intending process plays an important part to the successful completion of many daily activities. However, few researchers have paid attention to this issue. This study was set to investigate the time course and the electrophysiological evidence of the intending process with a cue-respond task.MethodsEvent-related potentials (ERPs) were recorded while participants were performing different cued conditions (deceptive, truthful, and watch-only). The time course of intending process was analyzed through the different effect of the cue stimuli.ResultsThe P2 component, that appeared between 200 and 400 ms after the cue was onset, can be observed in the intended conditions (deceptive, truthful), but cannot be found in un-intended condition (watch-only). The mean amplitude in P2 between the truthful and deceptive conditions was consistent with previous studies. P2 was thought to be the reflection of the intention process.ConclusionsThe results suggested that the intention process happened 200 to 400 ms after the cue stimuli was onset, and the P2 in the posterior scalp during this period could be a specific component that related with the process of intention.
740840
Fast, visual specialization for reading in English revealed by the topography of the N170 ERP response
BackgroundN170 effects associated with visual words may be related to perceptual expertise effects that have been demonstrated for faces and other extensively studied classes of visual stimuli. Although face and other object expertise effects are typically bilateral or right-lateralized, the spatial topography of reading-related N170 effects are often left-lateralized, providing potential insights into the unique aspects of reading-related perceptual expertise.MethodsExtending previous research in German [1], we use a high-density channel array to characterize the N170 topography for reading-related perceptual expertise in English, a language with inconsistent spelling-to-sound mapping. N170 effects related to overall reading-related expertise are defined by contrasting responses to visual words versus novel symbol strings. By contrasting each of these conditions to pseudowords, we examined how this reading-related N170 effect generalizes to well-ordered novel letter strings.ResultsA sample-by-sample permutation test computed on word versus symbol ERP topographies revealed differences during two time windows corresponding to the N170 and P300 components. Topographic centroid analysis of the word and symbol N170 demonstrated significant differences in both left-right as well as inferior-superior dimensions. Words elicited larger N170 negativities than symbols at inferior occipito-temporal channels, with the maximal effect over left inferior regions often unsampled in conventional electrode montages. Further contrasts produced inferior-superior topographic effects for the pseudoword-symbol comparison and left-lateralized topographic effects for the word-pseudoword comparison.ConclusionFast specialized perception related to reading experience produces an N170 modulation detectable across different EEG systems and different languages. Characterization of such effects may be improved by sampling with greater spatial frequency recordings that sample inferior regions. Unlike in German, reading-related expertise effects in English produced only partial generalization in N170 responses to novel pseudowords. The topographic inferior-superior N170 differences may reflect general perceptual expertise for orthographic strings, as it was found for words and pseudowords across both languages. The topographic left-right N170 difference between words and pseudowords was only found in English, and may suggest that ambiguity in pronunciating novel pseudowords due to inconsistency in spelling-to-sound mapping influences early stages of letter string processing.
8540255
N170 ERPs could represent a logographic processing strategy in visual word recognition
BackgroundOccipito-temporal N170 component represents the first step where face, object and word processing are discriminated along the ventral stream of the brain. N170 leftward asymmetry observed during reading has been often associated to prelexical orthographic visual word form activation. However, some studies reported a lexical frequency effect for this component particularly during word repetition that appears in contradiction with this prelexical orthographic step. Here, we tested the hypothesis that under word repetition condition, discrimination between words would be operated on visual rather than orthographic basis. In this case, N170 activity may correspond to a logographic processing where a word is processed as a whole.MethodsTo test such an assumption, frequent words, infrequent words and pseudowords were presented to the subjects that had to complete a visual lexical decision task. Different repetition conditions were defined 1 – weak repetition, 2 – massive repetition and 3 – massive repetition with font alternation. This last condition was designed to change visual word shape during repetition and therefore to interfere with a possible visual strategy during word recognition.ResultsBehavioral data showed an important frequency effect for the weak repetition condition, a lower but significant frequency effect for massive repetition, and no frequency effect for the changing font repetition. Moreover alternating font repetitions slowed subject's responses in comparison to "simple" massive repetition.ERPs results evidenced larger N170 amplitude in the left hemisphere for frequent than both infrequent words and pseudowords during massive repetition. Moreover, when words were repeated with different fonts this N170 effect was not present, suggesting a visual locus for such a N170 frequency effect.ConclusionN170 represents an important step in visual word recognition, consisting probably in a prelexical orthographic processing. But during the reading of very frequent words or after a massive repetition of a word, it could represent a more holistic process where words are processed as a global visual pattern.
24615381
Emotional conflict occurs at an early stage: Evidence from the emotional face–word Stroop task
The perceptual processing of emotional conflict was studied using electrophysiological techniques to measure event-related potentials (ERPs). The emotional face-word Stroop task in which emotion words are written in prominent red color across a face was use to study emotional conflict. In each trial, the emotion word and facial expression were either congruent or incongruent (in conflict). When subjects were asked to identify the expression of the face during a trial, the incongruent condition evoked a more negative N170 ERP component in posterior lateral sites than in the congruent condition. In contrast, when subjects were asked to identify the word during a trial, the incongruent condition evoked a less negative N170 component than the congruent condition. The present findings extend our understanding of the control processes involved in emotional conflict by demonstrating that differentiation of emotional congruency begins at an early perceptual processing stage.
5675949
The neural correlates of race
Behavioral analyses are a natural choice for understanding the wide-ranging behavioral consequences of racial stereotyping and prejudice. However, studies using neuroimaging and electrophysiological research have recently considered the neural mechanisms that underlie racial categorization and the activation and application of racial stereotypes and prejudice, revealing exciting new insights. Work that we review here points to the importance of neural structures previously associated with face processing, semantic knowledge activation, evaluation and self-regulatory behavioral control, enabling specification of a neural model of race processing. We show how research on the neural correlates of race can serve to link otherwise disparate lines of evidence on the neural underpinnings of a broad array of social-cognitive phenomena; we also consider the implications for effecting change in race relations.
14760952
Mechanisms of face perception.
Faces are among the most informative stimuli we ever perceive: Even a split-second glimpse of a person's face tells us his identity, sex, mood, age, race, and direction of attention. The specialness of face processing is acknowledged in the artificial vision community, where contests for face-recognition algorithms abound. Neurological evidence strongly implicates a dedicated machinery for face processing in the human brain to explain the double dissociability of face- and object-recognition deficits. Furthermore, recent evidence shows that macaques too have specialized neural machinery for processing faces. Here we propose a unifying hypothesis, deduced from computational, neurological, fMRI, and single-unit experiments: that what makes face processing special is that it is gated by an obligatory detection process. We clarify this idea in concrete algorithmic terms and show how it can explain a variety of phenomena associated with face processing.
13541657
Word repetition within- and across-visual fields: an event-related potential study
A divided visual field (DVF) procedure was used to investigate the scalp distribution of the event-related potential (ERP) repetition effect. ERPs were recorded from 27 scalp sites whilst subjects (n = 20) discriminated between words and non-words presented to either the left (LVF) or the right (RVF) visual field. A proportion of the words were repeated on the trial immediately following their first presentation. In two within-field repetition conditions the two encounters with a word occurred in the same visual field (LVF or RVF). In two across-field repetition conditions, the two encounters with a word occurred in different visual fields. For both words and non-words, task performance was better for RVF presentations than for LVF presentations. In each repetition condition there was a positive-going shift in the ERP elicited by repeated words compared to that elicited by words on their first presentation. This ERP repetition effect was equivalent in magnitude and lateralised to the right hemisphere to an equivalent degree in all four repetition conditions. It is suggested that the ERP effects largely reflect the processing of visual form thought to occur predominately in the right hemisphere.
1325635
Event-related brain potentials dissociate repetition effects of high-and low-frequency words
Event-related brain potentials (ERPs) were recorded while subjects detected nonwords interspersed among sequences of words of high or low frequency of occurrence. In Phase 1, a proportion of the words were repeated after six intervening items. In Phase 2, which followed after a break of approximately 15 min, the words were either repeats of items presented in the previous phase or new. Unrepeated low-frequency words evoked larger N400 components than did high-frequency items. In Phase 1, this effect interacted with repetition, suchthatnofreqiiency effects were observed on N400s evoked by repeated words. In addition, the post-500-msec latency region of the ERPs exhibited a substantial repetition effect for low-frequency words, but did not differentiate unrepeated and repeated high-frequency words. In Phase 2, ERPs evoked by “old” and “new” high-frequency words did not differ in any latency region, while those evoked by old and new low-frequency words differed only after 500 msec. The interactive effects of frequency and repetition suggest that these variables act jointly at multiple loci during the processing of a word. The specificity of the post-500-msec repetition effect for low-frequency words may reflect a process responsive to a discrepancy between words’ intra and extraexperimental familiarity.
14963191
Word repetition effects on event-related potentials in healthy young and old subjects, and in patients with alzheimer-type dementia
Event-related potentials (ERPs) were recorded from 16 healthy young (mean age 21 years) and 16 healthy old subjects (mean age 64 years), and from 11 subjects with a diagnosis of Dementia of Alzheimer Type (DAT). The task requirement was to attend to a series of visually presented words so as to respond to occasional animal names. Non-animal names repeated after either a single or six intervening items. In the young subjects ERPs evoked by repeated words displayed a widespread, sustained positive-going shift relative to ERPs evoked by first presentations (the ERP repetition effect). This effect onset around 220 msec and did not differ as a function of inter-item lag. Other than for a delay in onset of approximately 80 msec, the ERP repetition effect in the healthy old group was in all respects equivalent to that of the young subjects. The ERP repetition effects in the DAT patients were statistically indistinguishable from those of an appropriately matched sub-set of the healthy old subjects. These results indicate that the ERP repetition effect remains robust in subjects in whom explicit memory has declined as a result of normal aging or DAT. Thus they suggest that the effect reflects processes independent of those underlying explicit memory, and that it may index a form of memory relatively unaffected by the pathology underlying DAT.
26040654
ERP repetition effects in indirect and direct tasks: effects of age and interitem lag.
Event-related potentials (ERPs) were recorded for visually presented words in young and older participants while they performed two tasks. In the indirect task, participants responded to occasional target words. Some of the nontarget words were repeated after a single intervening trial, and others were repeated after a mean of 10 trials. In the direct task participants responded to every item, discriminating between words presented for the first and the second times. Compared with ERPs to unrepeated words, those to words repeated in the indirect task after either lag were more positive in both participant groups. For the short lag, this effect was larger among the older participants. In the direct task, words repeated after either lag elicited a positive shift in the ERPs of the young participants. In the older participants, short lag repeats elicited a repetition effect, but smaller than the equivalent effect among the young participants. Long lag repeats failed to elicit a repetition effect in the direct task in the older participants. The findings show that word repetition in these tasks reflects the modulation of two ERP components, which differ in their sensitivity to age-related changes in memory function.
615039
Event-related potentials to task-irrelevant changes in facial expressions
BackgroundNumerous previous experiments have used oddball paradigm to study change detection. This paradigm is applied here to study change detection of facial expressions in a context which demands abstraction of the emotional expression-related facial features among other changing facial features.MethodsEvent-related potentials (ERPs) were recorded in adult humans engaged in a demanding auditory task. In an oddball paradigm, repeated pictures of faces with a neutral expression ('standard', p = .9) were rarely replaced by pictures with a fearful ('fearful deviant', p = .05) or happy ('happy deviant', p = .05) expression. Importantly, facial identities changed from picture to picture. Thus, change detection required abstraction of facial expression from changes in several low-level visual features.ResultsERPs to both types of deviants differed from those to standards. At occipital electrode sites, ERPs to deviants were more negative than ERPs to standards at 150–180 ms and 280–320 ms post-stimulus. A positive shift to deviants at fronto-central electrode sites in the analysis window of 130–170 ms post-stimulus was also found. Waveform analysis computed as point-wise comparisons between the amplitudes elicited by standards and deviants revealed that the occipital negativity emerged earlier to happy deviants than to fearful deviants (after 140 ms versus 160 ms post-stimulus, respectively). In turn, the anterior positivity was earlier to fearful deviants than to happy deviants (110 ms versus 120 ms post-stimulus, respectively).ConclusionERP amplitude differences between emotional and neutral expressions indicated pre-attentive change detection of facial expressions among neutral faces. The posterior negative difference at 150–180 ms latency resembled visual mismatch negativity (vMMN) – an index of pre-attentive change detection previously studied only to changes in low-level features in vision. The positive anterior difference in ERPs at 130–170 ms post-stimulus probably indexed pre-attentive attention orienting towards emotionally significant changes. The results show that the human brain can abstract emotion related features of faces while engaged to a demanding task in another sensory modality.
5765648
Gesture and metaphor comprehension: Electrophysiological evidence of cross-modal coordination by audiovisual stimulation
In recent years, studies have suggested that gestures influence comprehension of linguistic expressions, for example, eliciting an N400 component in response to a speech/gesture mismatch. In this paper, we investigate the role of gestural information in the understanding of metaphors. Event related potentials (ERPs) were recorded while participants viewed video clips of an actor uttering metaphorical expressions and producing bodily gestures that were congruent or incongruent with the metaphorical meaning of such expressions. This modality of stimuli presentation allows a more ecological approach to meaning integration. When ERPs were calculated using gesture stroke as time-lock event, gesture incongruity with metaphorical expression modulated the amplitude of the N400 and of the late positive complex (LPC). This suggests that gestural and speech information are combined online to make sense of the interlocutor's linguistic production in an early stage of metaphor comprehension. Our data favor the idea that meaning construction is globally integrative and highly context-sensitive.
20464769
Gesture influences the processing of figurative language in non-native speakers: ERP evidence
Gestures should play a role in second language comprehension, given their importance in conveying contextual information. In this study, the N400 and the LPC were evaluated in a task involving the observation of videos showing utterances accompanied by gestures. Students studying advanced (G-High participants) and basic German (G-Low participants) as a second language were investigated. The utterance-gesture congruence and metaphoric meaning of content were manipulated during the task. As in previous ERP reports with native speakers, metaphorical expressions were sensitive to gestures. In G-Low participants, no modulation in the 300-500 ms window was observed, and only a modest effect was observed for the 500-700 ms window. More subtle differences of verbal expression were not processed in this group. Consistent with previous reports of the same paradigm with native speakers, the N400 from G-High group discriminated both congruent and incongruent gestures as well as literal and metaphorical sentences. Our results suggest that semantic processing is robust in the learning of a second language, although the amplitude modulation and latency of ERPs might depend on the speaker's proficiency level.
13522362
Spatiotemporal dipole source localization of face processing ERPs in adolescents: a preliminary study
BackgroundDespite extensive investigation of the neural systems for face perception and emotion recognition in adults and young children in the past, the precise temporal activation of brain sources specific to the processing of emotional facial expressions in older children and adolescents is not well known. This preliminary study aims to trace the spatiotemporal dynamics of facial emotion processing during adolescence and provide a basis for future developmental studies and comparisons with patient populations that have social-emotional deficits such as autism.MethodsWe presented pictures showing happy, angry, fearful, or neutral facial expressions to healthy adolescents (aged 10–16 years) and recorded 128-channel event-related potentials (ERPs) while they performed an emotion discrimination task. ERP components were analyzed for effects of age and emotion on amplitude and latency. The underlying cortical sources of scalp ERP activity were modeled as multiple equivalent current dipoles using Brain Electrical Source Analysis (BESA).ResultsInitial global/holistic processing of faces (P1) took place in the visual association cortex (lingual gyrus) around 120 ms post-stimulus. Next, structural encoding of facial features (N170) occurred between 160–200 ms in the inferior temporal/fusiform region, and perhaps early emotion processing (Vertex Positive Potential or VPP) in the amygdala and orbitofrontal cortex. Finally, cognitive analysis of facial expressions (P2) in the prefrontal cortex and emotional reactions in somatosensory areas were observed from about 230 ms onwards. The temporal sequence of cortical source activation in response to facial emotion processing was occipital, prefrontal, fusiform, parietal for young adolescents and occipital, limbic, inferior temporal, and prefrontal for older adolescents.ConclusionThis is a first report of high-density ERP dipole source analysis in healthy adolescents which traces the sequence of neural activity within the first 500 ms of categorizing emotion from faces. Our spatio-temporal brain source models showed the presence of adult-like cortical networks for face processing in adolescents, whose functional specificity to different emotions appear to be not yet fully mature. Age-related differences in brain activation patterns illustrate the continued development and maturation of distinct neural systems for processing facial expressions during adolescence and possible changes in emotion perception, experience, and reaction with age.
1230274
Attention-deficit hyperactivity disorder involves differential cortical processing in a visual spatial attention paradigm
OBJECTIVE
Inattention is undoubtedly one of the main characteristics of Attention-deficit hyperactivity disorder (ADHD). Nevertheless, a growing corpus of evidence shows that not all attentional processes are affected in this condition. This study aimed to explore the distribution of attentional resources in children with ADHD via a spatially shifted double-oddball visual task.


METHODS
We recorded event-related potentials (ERPs) for all visual stimuli. Subjects were instructed to allocate attention in a specific area of visual space while ignoring all stimuli presented outside. Ten male children (age: 9-14; mean = 11.6 +/- 2.1) who met DSM-IV criteria for the ADHD combined subtype participated in the study, along with ten age- and sex-matched healthy controls (9-14; mean = 11.2 +/- 2.3).


RESULTS
ADHD subjects showed late differential cortical responses to initially suppressed irrelevant stimuli. The amplitude of early N1-P1 components were mainly modulated by stimulus location and showed no significant differences between groups, but a late P300-like positivity was clearly evoked in the ADHD group by peripheral stimuli.


CONCLUSIONS
These results suggest that ADHD may not compromise the early attentional spatial filter but rather entails a different distribution of attentional resources at later stages of cortical processing. Perhaps these differences may be attributable to individual differences in attentional mechanisms.


SIGNIFICANCE
ADHD may not affect initial focusing of visual attention but rather the allocation of processing resources in later stages.
41048147
Neurophysiology in Preschool Improves Behavioral Prediction of Reading Ability Throughout Primary School
BACKGROUND
More struggling readers could profit from additional help at the beginning of reading acquisition if dyslexia prediction were more successful. Currently, prediction is based only on behavioral assessment of early phonological processing deficits associated with dyslexia, but it might be improved by adding brain-based measures.


METHODS
In a 5-year longitudinal study of children with (n = 21) and without (n = 23) familial risk for dyslexia, we tested whether neurophysiological measures of automatic phoneme and tone deviance processing obtained in kindergarten would improve prediction of reading over behavioral measures alone.


RESULTS
Together, neurophysiological and behavioral measures obtained in kindergarten significantly predicted reading in school. Particularly the late mismatch negativity measure that indicated hemispheric lateralization of automatic phoneme processing improved prediction of reading ability over behavioral measures. It was also the only significant predictor for long-term reading success in fifth grade. Importantly, this result also held for the subgroup of children at familial risk.


CONCLUSIONS
The results demonstrate that brain-based measures of processing deficits associated with dyslexia improve prediction of reading and thus may be further evaluated to complement clinical practice of dyslexia prediction, especially in targeted populations, such as children with a familial risk.
11036748
Method-specific variance in the implicit association test.
The Implicit Association Test (IAT; A. G. Greenwald, D. E. McGhee, & J. L. K. Schwartz, 1998) can be used to assess interindividual differences in the strength of associative links between representational structures such as attitude objects and evaluations. Four experiments are reported that explore the extent of method-specific variance in the IAT. The most important findings are that conventionally scored IAT effects contain reliable interindividual differences that are method specific but independent of the measures' content, and that IAT effects can be obtained in the absence of a preexisting association between the response categories. Several techniques to decrease the impact of method-specific variance are evaluated. The best results were obtained with the D measures recently proposed by A. G. Greenwald, B. A. Nosek, and M. R. Banaji (2003).
794059
Separating multiple processes in implicit social cognition: the quad model of implicit task performance.
The authors argue that implicit measures of social cognition do not reflect only automatic processes but rather the joint contributions of multiple, qualitatively different processes. The quadruple process model proposed and tested in the present article quantitatively disentangles the influences of 4 distinct processes on implicit task performance: the likelihood that automatic bias is activated by a stimulus; that a correct response can be determined; that automatic bias is overcome; and that, in the absence of other information, a guessing bias drives responses. The stochastic and construct validity of the model is confirmed in 5 studies. The model is shown to provide a more nuanced and detailed understanding of the interplay of multiple processes in implicit task performance, including implicit measures of attitudes, prejudice, and stereotyping.
15818567
Individual differences in emotion processing
Recent functional brain imaging studies of the neurobiology of emotion have investigated how individual differences among subjects modulate neural responses during emotion processing. Differences in personality, dispositional affect, biological sex, and genotype can all substantially modulate the neural bases of emotion processing in prefrontal, limbic, and other brain regions, across a variety of domains including emotional reactions, emotional memory, and emotion perception. Analysis of individual differences provides a new window into the neurobiology of emotion processing that complements traditional approaches.
28695037
Does the compatibility effect in the race Implicit Association Test reflect familiarity or affect?
In the Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) involving race classification (white vs. black), an apparent compatibility effect is found between the “pleasant” attribute and the “white” category. This race IAT effect has been interpreted in terms of “implicit prejudice”—that is, more positive evaluation of whites than of blacks that is not open to consciousness. We suggested instead that the race IAT effect is better interpreted in terms of the salience asymmetry account proposed by Rothermund and Wentura (2004), whereby greater familiarity with the white category makes it more salient. Evidence that has been presented against the familiarity interpretation is considered, and alternative interpretations of findings related to the race IAT effect are discussed.
102322107
The propositional approach to associative learning as an alternative for association formation models
Associative learning effects can be defined as changes in behavior that are due to relations between events in the world. Most often, these effects are explained in terms of the formation of unqualified associations in memory. I describe an alternative theoretical explanation, according to which associative learning effects are the result of the nonautomatic generation and evaluation of propositions about relations between events. This idea is supported by many studies showing that associative learning effects are determined not only by the direct experience of events but also by prior knowledge, instructions, intervention, and deductive reasoning. Moreover, evidence supports the assumption that associative learning effects depend on nonautomatic processes. Whereas a propositional approach thus offers many new insights, questions can be raised about what the idea of association formation adds to our understanding of associative learning.
5049437
Event-related potentials with the Stroop colour-word task: timing of semantic conflict.
Event-Related Potentials (ERPs) elicited by congruent and incongruent colour-word stimuli of a Stroop paradigm, in a task in which participants were required to judge the congruence/incongruence of the two dimensions of the stimuli, were recorded in order to study the timing of the semantic conflict. The reaction time to colour-word incongruent stimuli was significantly longer than the reaction time to congruent stimuli (the Stroop effect). A temporal Principal Components Analysis was applied to the data to identify the ERP components. Three positive components were identified in the 300-600 ms interval in response to the congruent and incongruent stimuli: First P3, P3b and PSW. The factor scores corresponding to the First P3 and P3b components were significantly smaller for the incongruent stimuli than for the congruent stimuli. No differences between stimuli were observed in the factor scores corresponding to the PSW or in the ERP latencies. We conclude that the temporal locus of the semantic conflict, which intervenes in generating the Stroop effect, may occur within the time interval in which the First P3 and P3b components are identified, i.e. at approximately 300-450 ms post-stimulus. We suggest that the semantic conflict delays the start of the response selection process, which explains the longer reaction time to incongruent stimuli.
836430
Anterior cingulate cortex and conflict detection: An update of theory and data
The dorsal anterior cingulate cortex (ACC) and associated regions of the medial frontal wall have often been hypothesized to play an important role in cognitive control. We have proposed that the ACC’s specific role in cognitive control is to detect conflict between simultaneously active, competing representations and to engage the dorsolateral prefrontal cortex (DLPFC) to resolve such conflict. Here we review some of the evidence supporting this theory, from event-related potential (ERP) and fMRI studies. We focus on data obtained from interference tasks, such as the Stroop task, and review the evidence that trial-to-trial changes in control engagement can be understood as driven by conflict detection; the data suggest that levels of activation of the ACC and the DLPFC in such tasks do indeed reflect conflict and control, respectively. We also discuss some discrepant results in the literature that highlight the need for future research.
2587609
The neural correlates and functional integration of cognitive control in a Stroop task
It is well known that performance on a given trial of a cognitive task is affected by the nature of previous trials. For example, conflict effects on interference tasks, such as the Stroop task, are reduced subsequent to high-conflict trials relative to low-conflict trials. This interaction effect between previous and current trial types is called "conflict adaptation" and thought to be due to processing adjustments in cognitive control. The current study aimed to identify the neural substrates of cognitive control during conflict adaptation by isolating neural correlates of reduced conflict from those of increased cognitive control. We expected cognitive control to be implemented by prefrontal cortex through context-specific modulation of posterior regions involved in sensory and motor aspects of task performance. We collected event-related fMRI data on a color-word naming Stroop task and found distinct fronto-parietal networks of current trial conflict detection and conflict adaptation through cognitive control. Conflict adaptation was associated with increased activity in left middle frontal gyrus (GFm) and superior frontal gyrus (GFs), consistent with increased cognitive control, and with decreased activity in bilateral prefrontal and parietal cortices, consistent with reduced response conflict. Psychophysiological interaction analysis (PPI) revealed that cognitive control activation in GFs and GFm was accompanied by increased functional integration with bilateral inferior frontal, right temporal and parietal areas, and the anterior cerebellum. These data suggest that cognitive control is implemented by medial and lateral prefrontal cortices that bias processes in regions that have been implicated in high-level perceptual and motor processes.
37120606
Prefrontal-cingulate activation during executive control: which comes first?
The Stroop test requires executive control functions, in particular inhibition of a learned routine (in this case, word reading). The spatiotemporal analysis of brain activation during Stroop task execution was performed in 16 healthy subjects using high-density event-related potentials (ERPs) and dipole source modeling (BESA software). Scalp ERP analysis revealed the neurophysiological substrate of the interference effect: first, a greater negativity in the incongruent as compared to the congruent and neutral conditions was found between 350 and 450 ms poststimulus over left frontocentral scalp regions. Source analysis of the difference wave (incongruent-congruent) indicated that a generator localized in left prefrontal cortex (PFC) contributed to this effect. Second, immediately after the first effect, a greater positivity in the incongruent as compared to the congruent and neutral conditions developed between 450 and 550 ms poststimulus over midline frontocentral scalp regions. A generator of this effect was located in right anterior cingulate cortex (ACC). ACC activation seems to follow the activation of PFC with some overlap between the two components. Possible interpretation of this finding is that PFC signals ACC when executive control is required and ACC implements the control.
20236242
Attentional origins of the Simon effect: Behavioral and electrophysiological evidence
An electrophysiological analysis of classification in the Garner paradigm was performed to investigate processing origins of the Simon effect. This effect is faster responding when stimulus location, though irrelevant to the task, is congruent with the response to the relevant stimulus dimension than when it is not. Participants used lateral keys to classify the timbre of tones presented to left or right headphones. Differences between S-R congruent and S-R incongruent trials were observed initially in the N2 ERP component (250 ms after stimulus onset), after the N1 component (100 ms after stimulus onset) showed evidence of a failure of selective attention to stimulus location. Reaction times to congruent and incongruent stimuli were strongly associated with the peak latency of the P3 decisional component. The results are consistent with models that attribute the Simon effect to the evidentiary weight attention assigns to spatial location when classifying the stimulus as signaling left or right.
3259688
The Electrophysiological Dynamics of Interference during the Stroop Task
If subjects are required to name the color of the word red printed in blue ink, interference between word meaning and ink color occurs, which slows down reaction time. This effect is well known as the Stroop effect. It is still an unresolved issue how the brain deals with interference in this type of task. To explore this question, an electroencephalogram (EEG) study was carried out. By analyzing several measures of EEG activity, two main findings emerged. First, the event-related potential (ERP) showed increased fronto-central negativity in a time window around 400 msec for incongruent items in contrast to congruent and neutral items. Source localization analysis revealed that a source in the anterior cingulate cortex (ACC) contributed most to the difference. Second, time-frequency analysis showed that theta oscillations (47 Hz) in the ACC increased linearly with increasing interference and that phase coupling between the ACC and the left prefrontal cortex was longer persistent for incongruent items compared to congruent and neutral items. These effects occurred at a time window around 600 msec. We conclude that interference between color naming and word meaning in the Stroop task manifests itself at around 400 msec and mainly activates the ACC. Thereafter, sustained phase coupling between the ACC and the prefrontal cortex occurs, which most likely reflects the engagement of cognitive control mechanisms.
25290652
The development of emotion perception in face and voice during infancy.
PURPOSE
Interacting with others by reading their emotional expressions is an essential social skill in humans. How this ability develops during infancy and what brain processes underpin infants' perception of emotion in different modalities are the questions dealt with in this paper.


METHODS
Literature review.


RESULTS
The first part provides a systematic review of behavioral findings on infants' developing emotion-reading abilities. The second part presents a set of new electrophysiological studies that provide insights into the brain processes underlying infants' developing abilities. Throughout, evidence from unimodal (face or voice) and multimodal (face and voice) processing of emotion is considered. The implications of the reviewed findings for our understanding of developmental models of emotion processing are discussed.


CONCLUSIONS
The reviewed infant data suggest that (a) early in development, emotion enhances the sensory processing of faces and voices, (b) infants' ability to allocate increased attentional resources to negative emotional information develops earlier in the vocal domain than in the facial domain, and (c) at least by the age of 7 months, infants reliably match and recognize emotional information across face and voice.
7920871
Fears, phobias, and preparedness: toward an evolved module of fear and fear learning.
An evolved module for fear elicitation and fear learning with 4 characteristics is proposed. (a) The fear module is preferentially activated in aversive contexts by stimuli that are fear relevant in an evolutionary perspective. (b) Its activation to such stimuli is automatic. (c) It is relatively impenetrable to cognitive control. (d) It originates in a dedicated neural circuitry, centered on the amygdala. Evidence supporting these propositions is reviewed from conditioning studies, both in humans and in monkeys; illusory correlation studies; studies using unreportable stimuli; and studies from animal neuroscience. The fear module is assumed to mediate an emotional level of fear learning that is relatively independent and dissociable from cognitive learning of stimulus relationships.
15795808
Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects
Background Behavioral studies have provided evidence for an action–sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. Methodology/Principal Findings Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. Conclusions/Significance The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction.
5389423
Theories and Theorizers: A Contextual Approach to Theories of Cognition
An undisputable characteristic of cognitive science is its enormous diversity of theories. Not surprisingly, these often belong to different paradigms that focus on different processes and levels of analysis. A related problem is that researchers of cognition frequently seem to ascribe to incompatible approaches to research, creating a Tower of Babel of cognitive knowledge. This text presents a pragmatic model of meta-theoretical analysis, a theory conceived of to examine other theories, which allows cognitive theories to be described, integrated and compared. After a brief introduction to meta-theoretical analysis in cognitive science, the dynamic and structural components of a theory are described. The analysis of conceptual mappings between components and explanation strategies is also described, as well as the processes of intra-theory generalization and inter-theory comparison. The various components of the meta-theoretical model are presented with examples of different cognitive theories, mainly focusing on two current approaches to research: The dynamical approach to cognition and the computer metaphor of mind. Finally, two potential counter arguments to the model are presented and discussed.
26108311
Human Cognition in Context: On the Biologic, Cognitive and Social Reconsideration of Meaning as Making Sense of Action
The aim of this special issue of IPBS has been to explore concrete and explicit alternatives to cognitivism. Indeed, in our editorial introduction we set out to give a brief survey of the numerous criticisms that have been made of understanding the mind this way (Ibáñez and Cosmelli, Integrative Psychological and Behavioral Sciences, 2008). Thus in what sense do the contributions here presented succeed in providing novel alternatives, moving into original and potentially generative domains of inquiry? While much remains to be done, we believe that they make significant headway in more than one sense. We do believe, however, that there is one locus that furnishes a convergence ground that is worth considering seriously: the problem of meaning. Meaning as making sense of contextualized action seems to cross the domains of intentionality, intersubjectivity and ecology of mind. The development of multilevel approaches, as the authors here exemplify, argues for a novel research agenda.
13333018
Decision-making cognition in neurodegenerative diseases
A large proportion of human social neuroscience research has focused on the issue of decision-making. Impaired decision-making is a symptomatic feature of a number of neurodegenerative diseases, but the nature of these decision-making deficits depends on the particular disease. Thus, examining the qualitative differences in decision-making impairments associated with different neurodegenerative diseases could provide valuable information regarding the underlying neural basis of decision-making. Nevertheless, few comparative reports of decision-making across patient groups exist. In this Review, we examine the neuroanatomical substrates of decision-making in relation to the neuropathological changes that occur in Alzheimer disease, frontotemporal dementia, Parkinson disease and Huntington disease. We then examine the main findings from studies of decision-making in these neurodegenerative diseases. Finally, we suggest a number of recommendations that future studies could adopt to aid our understanding of decision-making cognition.
22026861
ERPs and contextual semantic discrimination: Degrees of congruence in wakefulness and sleep
This study explores whether the brain can discriminate degrees of semantic congruency during wakefulness and sleep. Experiment 1 was conducted during wakefulness to test degrees of congruency by means of N400 amplitude. In Experiment 2, the same paradigm was applied to a different group of participants during natural night sleep. Stimuli were 108 sentences (definitions with two attributes) with four possible degrees of congruence as ending targets. In both studies, the amplitude of N400-like effect showed modulation according to the degree of congruency. The results indicate that the brain can accomplish sentential semantic discriminations not only in wakefulness but also in sleep.
143529482
Multi-level analysis of cultural phenomena: The role of ERPs approach to prejudice
Brain processes and social processes are not as separated as many of our Social Psychology and Neuroscience departments. This paper discusses the potential contribution of social neuroscience to the development of a multi-level, dynamic, and context-sensitive approach to prejudice. Specifically, the authors review research on event related potentials during social bias, stereotypes, and social attitudes measurements, showing that electrophysiological methods are powerful tools for analyzing the temporal fine-dynamics of psychological processes involved in implicit and explicit prejudice. Meta-theoretical implications are drawn regarding the social psychological modeling of social attitudes, and for the integration of social neuroscience into a multi-level account of cultural behavior.
9606025
High contextual sensitivity of metaphorical expressions and gesture blending: A video event-related potential design
Human communication in a natural context implies the dynamic coordination of contextual clues, paralinguistic information and literal as well as figurative language use. In the present study we constructed a paradigm with four types of video clips: literal and metaphorical expressions accompanied by congruent and incongruent gesture actions. Participants were instructed to classify the gesture accompanying the expression as congruent or incongruent by pressing two different keys while electrophysiological activity was being recorded. We compared behavioral measures and event related potential (ERP) differences triggered by the gesture stroke onset. Accuracy data showed that incongruent metaphorical expressions were more difficult to classify. Reaction times were modulated by incongruent gestures, by metaphorical expressions and by a gesture-expression interaction. No behavioral differences were found between the literal and metaphorical expressions when the gesture was congruent. N400-like and LPC-like (late positive complex) components from metaphorical expressions produced greater negativity. The N400-like modulation of metaphorical expressions showed a greater difference between congruent and incongruent categories over the left anterior region, compared with the literal expressions. More importantly, the literal congruent as well as the metaphorical congruent categories did not show any difference. Accuracy, reaction times and ERPs provide convergent support for a greater contextual sensitivity of the metaphorical expressions.
8088425
Context-sensitive social cognition is impaired in schizophrenic patients and their healthy relatives
Social cognition performance has been extensively studied within the schizophrenic population since Frith (1992) proposed amodel relatingmentalizing deficits and symptoms of the disorder. Moreover, recent research has suggested that social cognition is also impaired in unaffected relatives. Their deficits seem to be more pronounced when highly sophisticated tests are used (Janssen et al., 2003). Fifteen clinically-stable medicated schizophrenic patients from multiplex families, fourteen healthy first-degree relatives, and eighteen controls were examined. Groups were similar in age, education, and sex distribution. Initial selection criteria for all patients were: (1) diagnosis of paranoid schizophrenia according to DSM-IV-TR criteria (APA, 2000) and confirmed with Schedules of Clinical Assessment in Neuropsychiatry (SCAN) applied to both the patients and their relatives; and (2) the presence of one or more relativeswith the diagnosis of schizophrenia (no greater than third-degree relative), evidenced by the Family Interview for Genetic Studies (FIGS). Healthy relatives had to be first-degree relatives. SCANwas applied to relatives in order to rule out any psychiatric conditions in this group. All participants were between 20 and 55 years old. Participants completed written informed consent and were paid for their participation in the study. Participants completed the Raven's Coloured Progressive Matrices, Trail Making Test, Reading theMind in the Eyes, and Faux Pas Test. Additionally, Positive and Negative Syndrome Scale (PANSS) and Calgary Depression Scale for Schizophrenia were applied to patients to characterize symptomatology and mood. Detailed information about participants, results and discussion is presented as Supplementary data. Main results (Table 1) were:
1771932
Size and probability of rewards modulate the feedback error-related negativity associated with wins but not losses in a monetarily rewarded gambling task
Feedback error-related negativity (fERN) has been referred to as a negative deflection in the event related potential (ERP), which distinguishes between wins and losses in terms of expected and unexpected outcomes. Some studies refer to the "expected outcome" as the probability to win vs. to lose, and others as expected size of rewards. We still do not know much about whether these alternative interpretations of "expected outcome" affect the fERN in a different manner, nor do we know the effect of their interaction in an expected value fashion. We set a gambling task with four game categories; two had the same expected value, while the other two categories were equivalent to the first ones, but alternatively in the size or probability of the offered rewards. Results show that fERN preceded by a P200, and followed by a Pe-like wave differentiates between losing in the category with a higher expected value and the rest of the experimental conditions. fERN differentiates between wins and losses, but changes in the size and probability of rewards impact the fERN amplitude only in win conditions. Results also show greater positivity following win feedback when the size and/or probability of the outcome rewards were higher, so that the higher the expected value the greater the positivity following win feedback. Our findings support the notion that both the probability and size of the offered rewards modulate the motivational value for the win feedback, this being also true for their interaction in an expected value fashion.
44995406
Augmenting serotonin neurotransmission with citalopram modulates emotional expression decoding but not structural encoding of moderate intensity sad facial emotional stimuli: an event-related potential (ERP) investigation
Antidepressants targeting the serotonergic system have been shown to modulate biases in emotional processing. The effects of serotonergic modulation on the temporal course of emotional processing (accruing within milliseconds) are unknown. Furthermore, it is unknown how serotonin affects different stages of facial emotional processing. The current study investigated the effects of acute serotonin augmentation on event-related potential (ERP) measures associated with ‘structural encoding’ (N170) and emotion ‘expression decoding’ (N250 and a late slow-wave positive potential [LPP]) of happy and sad facial stimuli, relative to neutral facial stimuli. The study was a double-blind, placebo-controlled, cross-over design, in which 14 healthy male participants completed a facial recognition task under two acute treatment conditions: 1) placebo (PLB) and 2) 20 mg citalopram (CIT). ERP recording were conducted while subjects viewed neutral, happy and sad facial stimuli. Findings indicated that under PLB, the N170 was not modulated by valence (happy or sad versus neutral), but the N250 and LPP were enhanced for processing happy (relative to neutral) faces. Citalopram had no effect on the N170, but it enhanced the LPP for processing sad (relative to neutral) faces. These findings suggest that serotonin enhancement has selective and temporal effects on emotional face processing, with evidence for modulating processes associated with ‘expression decoding’ but not ‘structural encoding’. The enhanced cortical response to perception of moderately intense sad facial expressions following citalopram administration may relate to the cognitive processing of the social relevance or significance of such ambiguous stimuli.
15330522
Tracking the Timecourse of Social Perception: The Effects of Racial Cues on Event-Related Brain Potentials
Event-related potentials were used to track social perception processes associated with viewing faces of racial ingroup and outgroup members. Activity associated with three distinct processes was detected. First, peaking at approximately 170 ms, faces were distinguished from nonface stimuli. Second, peaking at approximately 250 ms, ingroup members were differentiated from outgroup members, with a larger component suggesting greater attention to ingroup members. This effect may reflect the spontaneous application of a deeper level of processing to ingroup members. Third, peaking at approximately 520 ms, evaluative differentiation of ingroup and outgroup members occurred, with greater ingroup bias displayed by those with higher levels of prejudice on an explicit measure. Together, the results demonstrate the promise of using neural processes to track the presence, timing, and degree of activation of components relevant to social perception, prejudice, and stereotyping.
14814717
Category Specificity in Early Perception: Face and Word N170 Responses Differ in Both Lateralization and Habituation Properties
N170 event-related potential (ERP) responses to both faces and visual words raises questions about category specific processing mechanisms during early perception and their neural basis. Topographic differences across word and face N170s suggests a form of category specific processing in early perception – the word N170 is consistently left-lateralized, while less consistent evidence supports a right-lateralization for the face N170. Additionally, the face N170 shows a reduction in amplitude across consecutive individual faces, a form of habituation that might differ across studies thereby helping to explain inconsistencies in lateralization. This effect remains unexplored for visual words. The current study directly contrasts N170 responses to words and faces within the same subjects, examining both category-level habituation and lateralization effects. ERP responses to a series of different faces and words were collected under two contexts: blocks that alternated faces and words vs. pure blocks of a single category designed to induce category-level habituation. Global and occipito-temporal measures of N170 amplitude demonstrated an interaction between category (words, faces) and block context (alternating categories, same category). N170 amplitude demonstrated class-level habituation for faces but not words. Furthermore, the pure block context diminished the right-lateralization of the face N170, pointing to class-level habituation as a factor that might drive inconsistencies in findings of right-lateralization across different paradigms. No analogous effect for the word N170 was found, suggesting category specificity for this form of habituation. Taken together, topographic and habituation effects suggest distinct forms of perceptual processing drive the face N170 and the visual word form N170.
425195
The selective processing of briefly presented affective pictures: an ERP analysis.
Recent event-related potential (ERP) studies revealed the selective processing of affective pictures. The present study explored whether the same phenomenon can be observed when pictures are presented only briefly. Toward this end, pleasant, neutral, and unpleasant pictures from the International Affective Pictures Series were presented for 120 ms while event related potentials were measured by dense sensor arrays. As observed for longer picture presentations, brief affective pictures were selectively processed. Specifically, pleasant and unpleasant pictures were associated with an early endogenous negative shift over temporo-occipital sensors compared to neutral images. In addition, affective pictures elicited enlarged late positive potentials over centro-parietal sensor sites relative to neutral images. These data suggest that a quick glimpse of emotionally relevant stimuli appears sufficient to tune the brain for selective perceptual processing.
5635384
Distributed and interactive brain mechanisms during emotion face perception: Evidence from functional neuroimaging
Brain imaging studies in humans have shown that face processing in several areas is modulated by the affective significance of faces, particularly with fearful expressions, but also with other social signals such gaze direction. Here we review haemodynamic and electrical neuroimaging results indicating that activity in the face-selective fusiform cortex may be enhanced by emotional (fearful) expressions, without explicit voluntary control, and presumably through direct feedback connections from the amygdala. fMRI studies show that these increased responses in fusiform cortex to fearful faces are abolished by amygdala damage in the ipsilateral hemisphere, despite preserved effects of voluntary attention on fusiform; whereas emotional increases can still arise despite deficits in attention or awareness following parietal damage, and appear relatively unaffected by pharmacological increases in cholinergic stimulation. Fear-related modulations of face processing driven by amygdala signals may implicate not only fusiform cortex, but also earlier visual areas in occipital cortex (e.g., V1) and other distant regions involved in social, cognitive, or somatic responses (e.g., superior temporal sulcus, cingulate, or parietal areas). In the temporal domain, evoked-potentials show a widespread time-course of emotional face perception, with some increases in the amplitude of responses recorded over both occipital and frontal regions for fearful relative to neutral faces (as well as in the amygdala and orbitofrontal cortex, when using intracranial recordings), but with different latencies post-stimulus onset. Early emotional responses may arise around 120ms, prior to a full visual categorization stage indexed by the face-selective N170 component, possibly reflecting rapid emotion processing based on crude visual cues in faces. Other electrical components arise at later latencies and involve more sustained activities, probably generated in associative or supramodal brain areas, and resulting in part from the modulatory signals received from amygdala. Altogether, these fMRI and ERP results demonstrate that emotion face perception is a complex process that cannot be related to a single neural event taking place in a single brain regions, but rather implicates an interactive network with distributed activity in time and space. Moreover, although traditional models in cognitive neuropsychology have often considered that facial expression and facial identity are processed along two separate pathways, evidence from fMRI and ERPs suggests instead that emotional processing can strongly affect brain systems responsible for face recognition and memory. The functional implications of these interactions remain to be fully explored, but might play an important role in the normal development of face processing skills and in some neuropsychiatric disorders.
11616506
Event-related potential studies of language and emotion: words, phrases, and task effects.
This chapter reviews research that focuses on the effects of emotionality of single words, and of simple phrases, on event-related brain potentials when these are presented visually in various tasks. In these studies, presentation of emotionally evocative language material has consistently elicited a late (c. 300-600 ms post-onset) positive-going, largely frontal-central shift in the event-related potentials (ERPs), relative to neutral materials. Overall, affectively pleasant and unpleasant words or phrases are quite similar in their neuroelectric profiles and rarely differ substantively. This emotionality effect is enhanced in both amplitude and latency when emotional content is task relevant, but is also reliably observed when the task involves other semantically engaging tasks. On the other hand, it can be attenuated or eliminated when the task does not involve semantic evaluation (e.g., lexical decisions to words or orthographic judgments to the spelling patterns) or when comprehension of phrases requires integration of the connotative meaning of several words (e.g., compare dead puppy and dead tyrant). Taken together, these studies suggest that the emotionality of written language has a rapid and robust impact on ERPs, which can be modulated by specific task demands as well as the linguistic context in which the affective stimulus occurs.
31823977
Localization of the event-related potential novelty response as defined by principal components analysis.
Recent research indicates that novel stimuli elicit at least two distinct components, the Novelty P3 and the P300. The P300 is thought to be elicited when a context updating mechanism is activated by a wide class of deviant events. The functional significance of the Novelty P3 is uncertain. Identification of the generator sources of the two components could provide additional information about their functional significance. Previous localization efforts have yielded conflicting results. The present report demonstrates that the use of principal components analysis (PCA) results in better convergence with knowledge about functional neuroanatomy than did previous localization efforts. The results are also more convincing than that obtained by two alternative methods, MUSIC-RAP and the Minimum Norm. Source modeling on 129-channel data with BESA and BrainVoyager suggests the P300 has sources in the temporal-parietal junction whereas the Novelty P3 has sources in the anterior cingulate.
22314639
An ERP study of category priming: Evidence of early lexical semantic access
We investigated the effects of lexical semantic access on early components of high-density ERPs. Participants performed five blocks of a standard lexical decision (LD) task in which visually presented words were distinguished from nonwords (pseudowords) matched on word length. A second condition involved a lexical semantic (LS) version, in which the words (e.g., tiger) used in each block were selected from a single category (e.g., animals). ERP results indicated that (1) a main effect of lexicality occurred at 100 ms with P1 amplitude greater for words than for nonwords; (2) a task effect for both words and nonwords was also found in the P1 amplitude (larger for LS); (3) a lexicalityxtask interaction in the N1 amplitude indicated lexical semantic access by 168 ms; (4) semantic facilitation of response time to word-nonword judgment may be largely explained by P1 enhancement. Our findings of an early lexicality effect at 100 ms and of semantic access by 168 ms is in accordance with results of recent ERP and eye movement studies.
6835241
Implicit measures: A normative analysis and review.
Implicit measures can be defined as outcomes of measurement procedures that are caused in an automatic manner by psychological attributes. To establish that a measurement outcome is an implicit measure, one should examine (a) whether the outcome is causally produced by the psychological attribute it was designed to measure, (b) the nature of the processes by which the attribute causes the outcome, and (c) whether these processes operate automatically. This normative analysis provides a heuristic framework for organizing past and future research on implicit measures. The authors illustrate the heuristic function of their framework by using it to review past research on the 2 implicit measures that are currently most popular: effects in implicit association tests and affective priming tasks. (PsycINFO Database Record (c) 2009 APA, all rights reserved).
7840819
Measuring individual differences in implicit cognition: the implicit association test.
An implicit association test (IAT) measures differential association of 2 target concepts with an attribute. The 2 concepts appear in a 2-choice task (2-choice task (e.g., flower vs. insect names), and the attribute in a 2nd task (e.g., pleasant vs. unpleasant words for an evaluation attribute). When instructions oblige highly associated categories (e.g., flower + pleasant) to share a response key, performance is faster than when less associated categories (e.g., insect & pleasant) share a key. This performance difference implicitly measures differential association of the 2 concepts with the attribute. In 3 experiments, the IAT was sensitive to (a) near-universal evaluative differences (e.g., flower vs. insect), (b) expected individual differences in evaluative associations (Japanese + pleasant vs. Korean + pleasant for Japanese vs. Korean subjects), and (c) consciously disavowed evaluative differences (Black + pleasant vs. White + pleasant for self-described unprejudiced White subjects).
13520928
Brain potentials in perception: picture complexity and emotional arousal.
Event-related potentials (ERPs) were measured while participants viewed affectively arousing and neutral pictures depicting either simple figure-ground compositions or more complex scenes to assess the timing and topography of perceptual and emotional modulation. Emotional pictures elicited a larger late positive potential than neutral pictures in a 400-700-ms window over centro-parietal sensors both for pictures with simple figure-ground composition and for more complex scenes. Picture composition affected ERPs beginning earlier (around 150 ms), with simple figure-ground compositions eliciting less positivity over posterior sensors and less negativity over frontal sensors. Emotionality had little effect on modulation of these early ERPs. These data suggest that the late centro-parietal positive potential primarily reflects motivational relevance, and that earlier posterior (and anterior) components reflect, at least in part, differences in a picture's perceptual organization.
7294983
Affective valence, stimulus attributes, and P300: color vs. black/white and normal vs. scrambled images.
Pictures from the International Affective Picture System (IAPS) were selected to manipulate affective valence (unpleasant, neutral, pleasant) while keeping arousal level the same. The pictures were presented in an oddball paradigm, with a visual pattern used as the standard stimulus. Subjects pressed a button whenever a target was detected. Experiment 1 presented normal pictures in color and black/white. Control stimuli were constructed for both the color and black/white conditions by randomly rearranging 1 cm square fragments of each original picture to produce a "scrambled" image. Experiment 2 presented the same normal color pictures with large, medium, and small scrambled condition (2, 1, and 0.5 cm squares). The P300 event-related brain potential demonstrated larger amplitudes over frontal areas for positive compared to negative or neutral images for normal color pictures in both experiments. Attenuated and nonsignificant valence effects were obtained for black/white images. Scrambled stimuli in each study yielded no valence effects but demonstrated typical P300 topography that increased from frontal to parietal areas. The findings suggest that P300 amplitude is sensitive to affective picture valence in the absence of stimulus arousal differences, and that stimulus color contributes to ERP valence effects.
13856563
Spatial frequencies or emotional effects? A systematic measure of spatial frequencies for IAPS pictures by a discrete wavelet analysis
The influence of the emotional attributes of a visual scene on early perception processes remains a key question in contemporary affective neurosciences. The International Affective Picture System (IAPS; Lang et al., 2005) was developed to provide a set of standardized stimuli for experimental investigations of emotional processes. These stimuli have been widely used in brain activity investigations to study the influence of valence and/or arousal on visual processing. However, visual perception is strongly influenced by the physical properties of the images shown, especially their spatial frequency content, an aspect that has been unexpectedly neglected at large. In this study, we examine the complete set of IAPS with a discrete wavelet transform to highlight relations between the energy in different spatial frequencies and the emotional features of the pictures. Our results showed that these associations are weak when the complete dataset is considered, but for selected subsets of pictures, clear differences are present in both affective and spatial frequency content. The IAPS remains a powerful tool to explore emotional processing, but we strongly suggest that researchers use subsets of images that are controlled for the energy of their spatial frequencies when investigating emotional influence on visual processing.
25458540
Affective visual event-related potentials: arousal, valence, and repetition effects for normal and distorted pictures.
Event-related potentials (ERPs) were used to assess arousal (low, high), valence (negative, positive), and stimulus repetition effects for normal and distorted images from the International Affective Pictures System (IAPS). Distorted stimuli were constructed by dividing each image into small squares and rearranging the segments randomly to produce a "scrambled" picture. Event-related potentials (ERPs) were elicited by presenting the normal and scrambled images as target stimuli, with a repeated visual pattern used as the standard stimulus. Participants (N=32) were instructed to press a button to the targets and ignore the standard. Stimulus repetition effects were assessed by presenting each stimulus twice in the normal and scrambled condition. High-arousal stimuli yielded larger late positive components for both the normal and scrambled pictures. No overall valence effects were obtained, but arousal and valence influenced component amplitudes for middle-latency ERPs from the scrambled stimuli. For the normal pictures, stimulus repetition was associated with increased component amplitudes for all potentials and decreased RTs of all affective categories. For the scrambled pictures, no repetition changes were obtained. The findings suggest that stimulus arousal level contributes more than valence to affective ERP measures for normal as well as perceptually distorted pictures. Stimulus repetition engages memory for previous normal picture items but is not influenced by affective category. Theoretical implications are discussed.
2588423
Emotion and motivation I: defensive and appetitive reactions in picture processing.
Emotional reactions are organized by underlying motivational states--defensive and appetitive--that have evolved to promote the survival of individuals and species. Affective responses were measured while participants viewed pictures with varied emotional and neutral content. Consistent with the motivational hypothesis, reports of the strongest emotional arousal, largest skin conductance responses, most pronounced cardiac deceleration, and greatest modulation of the startle reflex occurred when participants viewed pictures depicting threat, violent death, and erotica. Moreover, reflex modulation and conductance change varied with arousal, whereas facial patterns were content specific. The findings suggest that affective responses serve different functions-mobilization for action, attention, and social communication-and reflect the motivational system that is engaged, its intensity of activation, and the specific emotional context.