16260358
Metacognition of Working Memory Performance: Trial-by-Trial Subjective Effects from a New Paradigm
Investigators have begun to examine the fleeting urges and inclinations that subjects experience when performing tasks involving response interference and working memory. Building on this research, we developed a paradigm in which subjects, after learning to press certain buttons when presented with certain letters, are presented with two action-related letters (the memoranda) but must withhold responding (4 s) until cued to emit the response associated with only one of the two letters. In the Congruent condition, the action corresponds to the cue (e.g., memoranda = AB, cue = B, response = B); in the Incongruent condition, the action corresponds to the other item of the memoranda (e.g., memoranda = AB, cue = B, response = A). After each trial, subjects inputted a rating regarding their subjectively experienced “urge to err” on that trial. These introspection-based data revealed that, as found in previous research, urges to err were strongest for incongruent trials. Our findings reveal, first, that subjects can successfully perform this new task, even though it is more complex than that of previous studies, and second, that, in this new paradigm, reliable subjective, metacognitive data can be obtained on a trial-by-trial basis. We hope that our novel paradigm will serve as a foundation for future experimental projects on the relationship between working memory performance and consciousness—an under-explored nexus whose investigation is likely to reveal insights about working memory, cognitive control, and metacognition.
9762686
Conflict adaptation effects in the absence of executive control
According to the 'conflict-monitoring' model, a leading theory of cognitive control, information-processing conflict registered in the anterior cingulate cortex (ACC) triggers the prefrontal cortex to reduce conflict susceptibility. Here we show that the existing empirical support for an online modulation of susceptibility to conflict through immediately preceding conflict, the 'conflict-adaptation effect', needs to be reevaluated. In a human cognitive control task, we found that it was not the stimulus-independent level of conflict that was responsible for the conflict-adaptation effect but rather an episodic memory phenomenon: stimulus-specific priming.
2298524
The function of phenomenal states: supramodular interaction theory.
Discovering the function of phenomenal states remains a formidable scientific challenge. Research on consciously penetrable conflicts (e.g., "pain-for-gain" scenarios) and impenetrable conflicts (as in the pupillary reflex, ventriloquism, and the McGurk effect [H. McGurk & J. MacDonald, 1976]) reveals that these states integrate diverse kinds of information to yield adaptive action. Supramodular interaction theory proposes that phenomenal states play an essential role in permitting interactions among supramodular response systems--agentic, independent, multimodal, information-processing structures defined by their concerns (e.g., instrumental action vs. certain bodily needs). Unlike unconscious processes (e.g., pupillary reflex), these processes may conflict with skeletal muscle plans, as described by the principle of parallel responses into skeletal muscle (PRISM). Without phenomenal states, these systems would be encapsulated and incapable of collectively influencing skeletomotor action.
25915636
Evidence for a close relationship between conscious effort and anterior cingulate cortex activity.
The function of the anterior cingulate cortex (ACC) has been discussed in the last years in the context of conflict monitoring and error detection. In addition, ACC activity has been described in the context of "conscious effort". Recent neurophysiological and neuroimaging studies have described a negative correlation between ACC activity and reaction times in simple or choice reaction time experiments. One suggested explanation for this finding has been that there is a relationship between effort and ACC activity. The present ERP-LORETA study of healthy volunteers (n=35) was intended to directly investigate this relationship. In this experiment, three conditions were investigated: condition I was a choice reaction task with the instruction to stay relaxed during the task (relaxed condition), condition II was the same choice reaction task with the instruction to press the respective button as fast and correct as possible (effort condition). Condition III was just listening to the tones without button press (control condition). Subjects had to score directly after each experimental run on a visual analogue scale the amount of effort they have actually spent. The subjects showed significantly shorter reaction times during the high effort condition in comparison to the relaxed condition, as well as increased N1 amplitudes and increased ACC activity. In a subgroup analysis, this effect was present only in subjects who were (according to their self-ratings) following the instructions closely. These results provide direct evidence for a close relationship between conscious effort and ACC activity and suggest the usefulness of the applied effort-self-rating.
26151486
Subjective aspects of cognitive control at different stages of processing
Although research on cognitive control has addressed the effects that different forms of cognitive interference have on behavior and the activities of certain brain regions, until recently, the effects of interference on subjective experience have not been addressed. We demonstrate that, at the level of the individual trial, participants can reliably introspect the subjective aspects (e.g., perceptions of difficulty, competition, and control) of responding in interference paradigms. Similar subjective effects were obtained for both expressed and unexpressed (subvocalized) actions. Few participants discerned the source of these effects. These basic findings illuminate aspects of cognitive control and cognitive effort. In addition, these data have implications for the study of response interference in affect and self-control, and they begin to address theories regarding the function of consciousness.
16397403
The essence of conscious conflict: subjective effects of sustaining incompatible intentions.
Conflict constitutes one of the fundamental "tuggings and pullings" of the human experience. Yet, the link between the various kinds of conflict in the nervous system and subjective experience remains unexplained. The authors tested a hypothesis that predicts why both the "hot" conflicts involving self-control and motivation and the "cooler" response conflicts of the laboratory lead to changes in subjective experience. From this standpoint, these changes arise automatically from the activation of incompatible skeletomotor intentions, because the primary function of consciousness is to integrate such intentions for adaptive skeletal muscle output. Accordingly, the authors demonstrated for the first time that merely sustaining incompatible intentions (to move right and left) in a motionless state produces stronger subjective effects than sustaining compatible intentions. The results held equally strongly for two different effector systems involving skeletal muscle: arm movements and finger movements. In contrast, no such effects were found with conflict in a smooth muscle effector system. Together, these findings illuminate aspects of the nature of subjective experience and the role of incompatible intentions in affect and failures of self-control.
10436266
On the control of automatic processes: a parallel distributed processing account of the Stroop effect.
Traditional views of automaticity are in need of revision. For example, automaticity often has been treated as an all-or-none phenomenon, and traditional theories have held that automatic processes are independent of attention. Yet recent empirical data suggest that automatic processes are continuous, and furthermore are subject to attentional control. A model of attention is presented to address these issues. Within a parallel distributed processing framework, it is proposed that the attributes of automaticity depend on the strength of a processing pathway and that strength increases with training. With the Stroop effect as an example, automatic processes are shown to be continuous and to emerge gradually with practice. Specifically, a computational model of the Stroop task simulates the time course of processing as well as the effects of learning. This was accomplished by combining the cascade mechanism described by McClelland (1979) with the backpropagation learning algorithm (Rumelhart, Hinton, & Williams, 1986). The model can simulate performance in the standard Stroop task, as well as aspects of performance in variants of this task that manipulate stimulus-onset asynchrony, response set, and degree of practice. The model presented is contrasted against other models, and its relation to many of the central issues in the literature on attention, automaticity, and interference is discussed.
13505062
Interdimensional interference in the Stroop effect: uncovering the cognitive and neural anatomy of attention
In the classic Stroop effect, naming the color of an incompatible color word (e.g. the word RED printed in green ink; say, 'green') is much slower and more error-prone than is naming the color of a control item (e.g. XXX or CAT printed in green; say 'green'). This seemingly simple interference phenomenon has long provided a fertile testing ground for theories of the cognitive and neural components of selective attention. We present a sketch of the behavioral phenomenon, focusing on the idea that the relative automaticity of the two dimensions determines the direction and the degree of interdimensional interference between them. We then present an outline of current parallel processing explanations that instantiate this automaticity account, and we show how existing interference data are captured by such models. We also consider how Stroop facilitation (faster response of 'red' to RED printed in red) can be understood. Along the way, we describe research on two tasks that have emerged from the basic Stroop phenomenon - negative priming and the emotional Stroop task. Finally, we provide a survey of brain imaging research, highlighting the possible roles of the anterior cingulate in maintaining attentional set and in processing conflict or competition situations.
11801785
Information processing in visual search: A continuous flow conception and experimental results
This paper reexamines the visual search process, and visual information processing more generally, from a perspective of the continuous flow of information and responses through the visual system. The results from three experiments are reported which support the continuous flow conception: Information accumulates gradually in the visual system, with concurrent priming of responses. The first two experiments investigated the processing of display stimuli which varied in size and figure-ground contrast in a nonsearch task, and provided evidence confirming a continuous flow model. Experiment 3 employed an asynchronous onset of target and noise and provided convergent evidence of the accumulative nature of information and response priming in visual processing.
18711308
A psychophysiological investigation of the continuous flow model of human information processing.
Twelve subjects responded to target letters "H" or "S" by squeezing dynamometers with the left or right hand. Targets could be surrounded by compatible (e.g., HHHHH) or incompatible noise (SSHSS) letters. Measures of the P300 component of the event-related brain potential and of correct and incorrect electromyographic and squeeze activity were used to study stimulus evaluation and response-related processes. When incorrect squeeze activity was present, execution of the correct response was prolonged, indicating a process of response competition. This process occurred more often under incompatible noise conditions, which were also associated with a delayed P300. Thus, the noise/compatibility manipulation influenced both stimulus evaluation and response competition processes. In contrast, a warning tone that preceded array presentation on half the trials, increased response speed without influencing evaluation time. The data suggest that the latency and accuracy of overt behavioral responses are a function of (a) a response activation process controlled by an evaluation process that accumulates evidence gradually, (b) a response priming process that is independent of stimulus evaluation, and (c) a response competition process.
12614263
Anterior Cingulate Cortex, Conflict Monitoring, and Levels of Processing
It has been hypothesized that the anterior cingulate cortex (ACC) contributes to cognition by detecting conflicts that might occur during information processing, to signal the need to engage top-down attentional processes. The present study was designed to investigate which levels of processing are being monitored by the ACC for the presence of conflict. Event-related fMRI was used to measure the response of the ACC during an interference task in which distracting information could be congruent, conflicting at the level of stimulus identification, or conflicting at the response level. Although both types of conflict caused reaction time interference, the fMRI data showed that the ACC is responsive only to response conflict, even when controlling for reaction times. These results suggest a highly specific contribution of the ACC to executive functions, through the detection of conflicts occurring at later or response-related levels of processing.
46567627
Flanker effects on motor output and the late-level response activation hypothesis
When participants must respond to a relevant central target and ignore irrelevant flanking stimuli, the flankers produce a flanker compatibility effect on behavioural measures. Current accounts of the flanker compatibility effect assume that both target and flanker stimuli affect response activation. This idea is supported by electrophysiological studies, which show that irrelevant flanker stimuli can affect the motor system. The present experiments examined the characteristics of flanker effects on the motor system by analysing the details of the motor output with response force measures. A total of 60 participants responded in the flanker task to arrows (Experiment 1) or letters (Experiment 2). Reaction time as well as response force increased on incompatible trials. Analyses of the distribution of incorrect activation revealed that both response times and correct motor output increased with the amount of incorrect activity. However, the flanker compatibility effect was only marginally modulated by incorrect activity. Results suggest that the largest part of the flanker compatibility effect cannot be attributed to response activation and competition at late levels of the response system.
7533924
Cognitive and neural components of the phenomenology of agency
A primary aspect of the self is the sense of agency – the sense that one is causing an action. In the spirit of recent reductionistic approaches to other complex, multifaceted phenomena (e.g., working memory; cf. Johnson & Johnson, 2009), we attempt to unravel the sense of agency by investigating its most basic components, without invoking high-level conceptual or ‘central executive’ processes. After considering the high-level components of agency, we examine the cognitive and neural underpinnings of its low-level components, which include basic consciousness and subjective urges (e.g., the urge to breathe when holding one's breath). Regarding urges, a quantitative review revealed that certain inter-representational dynamics (conflicts between action plans, as when holding one's breath) reliably engender fundamental aspects both of the phenomenology of agency and of ‘something countering the will of the self’. The neural correlates of such dynamics, for both primordial urges (e.g., air hunger) and urges elicited in laboratory interference tasks, are entertained. In addition, we discuss the implications of this unique perspective for the study of disorders involving agency.
34070577
Attention and facilitation: converging information versus inadvertent reading in Stroop task performance.
Disagreement exists about whether color-word Stroop facilitation is caused by converging information (e.g., Cohen et al., 1990; Roelofs, 2003) or inadvertent reading (MacLeod & MacDonald, 2000). Four experiments tested between these hypotheses by examining Stroop effects on response time (RT) both within and between languages. Words cannot be read aloud to produce facilitation between languages. Dutch-English bilingual participants named color patches while trying to ignore Dutch or English color words presented at a wide range of preexposure and postexposure stimulus onset asynchronies. The color patches were named in Dutch (Experiments 1 and 2) or English (Experiments 3 and 4). In all experiments, Stroop facilitation and interference effects were obtained in mean RTs with similar time courses within and between languages. Facilitation was generally present throughout the entire RT distributions. These results suggest that Stroop interference and facilitation have a common locus within and between languages, supporting the converging information hypothesis of Stroop facilitation.
144074954
What Is an Output?
A recurrent idea in the history of psychology is that one is conscious of outputs but not of the complex processes underlying the generation of outputs, which is evident in the out-of-the-blue, “eureka-like” experiences associated with intuition. We examine how this idea may suffer from a logical fallacy and may thus have inadvertently hindered progress on the study of the intimate liaisons among high-level central processes, intuition, and overt action. It is proposed that, for various reasons, the only undisputable output in the nervous system is overt action. Once this is accepted, the overlooked relationship between conscious central processes and overt action can be examined. A review of the evidence reveals that conscious processing is in the business of, not low-level perceptual processing, motor control, or action production per se, but of constraining a peculiar form of knowledge-based, integrated action-goal selection, which can lead to integrated actions such as holding one's breath. Unconscious processing can influence behavior indirectly, by producing these conscious constraining dimensions that modulate action-goal selection, or directly, through unintegrated actions such as reflexively inhaling or responding to a subliminal stimulus. From this standpoint, eureka-like intuitions reflect not an atypical brain process but the general nature by which unconscious machinations influence action either directly or indirectly, through the limited purview of consciousness.
13351076
Failure of anterior cingulate activation and connectivity with the amygdala during implicit regulation of emotional processing in generalized anxiety disorder.
OBJECTIVE
Clinical data suggest that abnormalities in the regulation of emotional processing contribute to the pathophysiology of generalized anxiety disorder, yet these abnormalities remain poorly understood at the neurobiological level. The authors recently reported that in healthy volunteers the pregenual anterior cingulate regulates emotional conflict on a trial-by-trial basis by dampening activity in the amygdala. The authors also showed that this process is specific to the regulation of emotional, compared to nonemotional, conflict. Here the authors examined whether this form of noninstructed emotion regulation is perturbed in generalized anxiety disorder.


METHOD
Seventeen patients with generalized anxiety disorder and 24 healthy comparison subjects underwent functional MRI while performing an emotional conflict task that involved categorizing facial affect while ignoring overlaid affect label words. Behavioral and neural measures were used to compare trial-by-trial changes in conflict regulation.


RESULTS
Comparison subjects effectively regulated emotional conflict from trial to trial, even though they were unaware of having done so. By contrast, patients with generalized anxiety disorder were completely unable to regulate emotional conflict and failed to engage the pregenual anterior cingulate in ways that would dampen amygdalar activity. Moreover, performance and brain activation were correlated with symptoms and could be used to accurately classify the two groups.


CONCLUSIONS
These data demonstrate that patients with generalized anxiety disorder show significant deficits in the noninstructed and spontaneous regulation of emotional processing. Conceptualization of anxiety as importantly involving abnormalities in emotion regulation, particularly a type occurring outside of awareness, may open up avenues for novel treatments, such as by targeting the medial prefrontal cortex.
10214273
Explicit and implicit emotion regulation: A dual-process framework
It is widely acknowledged that emotions can be regulated in an astonishing variety of ways. Most research to date has focused on explicit (effortful) forms of emotion regulation. However, there is growing research interest in implicit (automatic) forms of emotion regulation. To organise emerging findings, we present a dual-process framework that integrates explicit and implicit forms of emotion regulation, and argue that both forms of regulation are necessary for well-being. In the first section of this review, we provide a broad overview of the construct of emotion regulation, with an emphasis on explicit and implicit processes. In the second section, we focus on explicit emotion regulation, considering both neural mechanisms that are associated with these processes and their experiential and physiological consequences. In the third section, we turn to several forms of implicit emotion regulation, and integrate the burgeoning literature in this area. We conclude by outlining open questions and areas for future research.
61301593
Plans and the Structure of Behavior
which is used to describe a third component of thinking processes, particularly preverbal, and it denotes the concept that the world is activated by some generalized "energy" that links together causally all objects and events ; it is presumably revealed by a person's lack of curiosity about causal connections, as though they were self-evident. Aside from the rather frequent use of such key words, having strong connotations for this reviewer far away from what the author is aiming to denote, the book is written in a lucid and stimulating style that makes reading it an invigorating intellectual exercise. It is a book that is likely to have somewhat limited attraction to the full-time clinician, especially one treating adult patients. And child psychiatrists and psychologists, if reasonably well read, will most likely be familiar with the majority of references from which this author has synthesized his material. On the other hand, the scholarly and refreshing con¬ ceptual approaches of the author will appeal to psychologists, philosophers, linguists, and psychiatrists with a research bent and anyone else who wants to be provoked to do some thinking on the problems of language, language development, and the psychology of cognition. Louis A. GOTTSCHALK, M.D. Plans and the Structure of Behavior. By George A Miller, Eugene gALANTER, and Karl H. Pribram. Price, $5.00. Pp. 226. Henry Holt & Co., Inc., New York 17, 1960. This is an important book for psychiatrists and behavioral scientists, since it presents a clear, concise study of the application of cybernetics, information and computer theory to the problem of analyzing behavior. The authors have been actively engaged in behavioral research in different areas\p=m-\Millerin information and communication, Galanter in experimental psychology, and Pribram in neurophysiology. The book resulted from a series of discussions which they engaged in during a year they spent together at the Center for Advanced Study in the Behavioral Sciences, Palo Alto, Calif. Their original intent was to write a diary, as it were, of the development of their ideas and, fortunately, enough of this remains to make the book clear, easy to read, and interesting. It is also fortunate, however, that in the final writing a variety of studies comparing the "behavior" of computing machines with human "cognitive behavior" have been reviewed and summarized. The result is one of the best presentations of the present status of the brain-computer problem. The authors, however, do not discuss certain aspects of this problem, such as the difference between the brain and its vast number of parallel channels, but few operations, and the modern high-speed computer with its few channels and vast numbers of operations. This omission is consistent with their interest, since it would introduce the question of mechanisms rather than the problem of the structure of behavior as it is observed in everyday life in the clinic and in experiments on learning, conditioning, etc. Similarly, they do not discuss the qualitative differences between mechanisms of memory in the computer and those in the brain. In the former, a "memory"\p=m-\ i.e., stored information\p=m-\isidentified, metaphorically speaking, by an address, whereas no such mechanism is known in the brain (personal communication, Dr. Julian Bigelow). With few exceptions, however, the data, concepts, and theories presented are handled with elegant precision, as illustrated by the discussion of Sherrington's concepts of the "Reflex" and the "Synapse," Kurt Lewin's ideas of "tension states," and the numerous references to the work of Newell, Shaw, and Simon on computers and logic. There are, nevertheless, areas with
141716602
Cognitive Psychology. (Book Reviews: Cognition and Reality. Principles and Implications of Cognitive Psychology)
DOWNLOAD http://bit.ly/1ahnv9u Cognition and Reality: Principles and Implications of Cognitive Psychology Surveys contemporary theories of perception, criticizing mechanistic information-processing models and stressing differences between perception in the external world and in experimental laboratory situations This book presents a general and formal theory of meaning, signs, and language. The theory is presented in a clear and consistent way offering novel and provocative insights. book explores the representational powers of a person's mind.. A book/disk/3-D glasses package that explains the concepts behind VR and provides fascinating software for readers who want to explore this rapidly-evolving topic. This book. pages. This important book focuses on the role of human factors in the design and use of automobiles. It should review current knowledge of human characteristics as related to.
38891668
Working memory
It is suggested that working memory comprises a system for the temporary storage and manipulation of information, forming an important link between perception and controlled action. Evidence is presented for a three-component model, comprising an attentional control system, the central executive, and two subsidiary slave systems. One of these the, the visuo-spatial sketch pad holds and manipulates spatial information, while the other, the phonological loop performs a similar function for auditory and speech-based information. Evidence is presented for the view that the phonological loop has evolved as a mechanism to facilitate the acquisition of language.
142763675
Working Memory, Thought, and Action
1. Introduction and overview 2. Why do we need a phonological loop? 3. The phonological loop: challenges and growing points 4. Visuospatial short-term memory 5. Imagery and the visuospatial sketchpad 6. Recency retrieval and the constant ratio rule 7. Fractionating the central executive 8. Long-term memory and the episodic buffer 9. Exploring the episodic buffer 10. Individual differences in working memory 11. What limits working memory span 12. Neuroimaging working memory 13. Working memory and social behaviour 14. Working memory and emotion I: fear and craving 15. Working memory and emotion II: depression and the well-springs of action 16. Working memory and consciousness 17. Multilevel control of action 18. Working memory in context: life, the universe and everything
142766669
Consciousness: Creeping up on the Hard Problem
1. Stances towards the problem of consciousness 2. The illusory narrative of consciousness 3. Where science and consciousness meet 4. Intentionality 5. Reality and illusion 6. Enter qualia 7. A survival value for consciousness? 8. Creeping up on the hard problem 9. Epiphenomenalism revisited 10. Scrutinising functionalism 11. From Cartesian theatre to global workspace 12. The global neuronal workspace 13. The neural correlate of consciousness 14. Bottom-up vs top-down processing 15. Egocentric space and the parietal lobes 16. Taking physics seriously 17. Consciousness of self: the point of view 18. The bodily senses 19. Responsibility 20. Overview
145382683
Attention to Information in Working Memory
Working memory retains information and makes it available for processing. People often need to hold several chunks of information available while concentrating on only one of them. This process requires selective attention to the contents of working memory. In this article, we summarize evidence for both a broad focus of attention with a capacity of approximately four chunks and a narrow focus of attention that selects a single chunk at a time.
6815466
Representations in working memory yield interference effects found with externally-triggered representations.
An act as simple as flicking a switch involves various stages of processing. Each stage is susceptible to interference from competing representations/processes. Interference at different stages of processing (e.g., perceptual stages versus response selection stages) leads to distinct behavioral, neural, and subjective effects. In the flanker task, for instance, one responds to a visual target and disregards flanking 'distractors.' Theoretically-predicted interference (increased response times, error rates, and subjective 'urges to err') is stronger when distractors and targets are associated with different actions (response interference) than when they look different but are associated with the same action (perceptual interference). Extant versions of the task tax working memory (WM) minimally, but many everyday actions (e.g., searching for keys or holding one's breath) require more WM-based control. To illuminate this uncharted area, we examined the nature of interference in delayed action tasks, which rely on WM. We found that systematic interference arises even when action-related representations are, not triggered solely by external stimuli, but actively held in WM. We discuss these findings with increased emphasis on the under-explored subjective effects of different kinds of interference. The implications of these findings for the study of action production, WM, and conscious processing are entertained.
14957376
Subjective aspects of working memory performance: Memoranda-related imagery
Although it is well accepted that working memory (WM) is intimately related to consciousness, little research has illuminated the liaison between the two phenomena. To investigate this under-explored nexus, we used an imagery monitoring task to investigate the subjective aspects of WM performance. Specifically, in two experiments, we examined the effects on consciousness of (a) holding in mind information having a low versus high memory load, and (b) holding memoranda in mind during the presentation of distractors (e.g., visual stimuli associated with a response incompatible with that of the memoranda). Higher rates of rehearsal (conscious imagery) occurred in the high load and distractor conditions than in comparable control conditions. Examination of the temporal properties of the rehearsal-based imagery revealed that, across subjects, imagery events occurred evenly throughout the delay. We hope that future variants of this new imagery monitoring task will reveal additional insights about WM, consciousness, and action control.
144198339
Short-term recall as a function of covert rehearsal and of intervening task
Experiment I found that memory for trigrams was better if the intervening task was counting backward by 3's rather than by 7's. On the assumption that varying difficulty in the intervening task affects rehearsal ease, Ss in Experiment II were instructed to report rehearsals via button pressing. Intervening tasks consisted of counting backward by 3's or by 7's after auditory trigram presentation, and of shadowing after visual or auditory trigram presentation. The results indicated that: (a) More rehearsals occurred during shadowing than during counting backward. Within shadowing, more rehearsals occurred after visual than auditory presentation. Within counting backward, more rehearsals occurred while counting by 3's than by 7's. (b) Rehearsals were least effective while shadowing after auditory trigram presentation, while rehearsals were equally effective during the other three conditions. (c) On trials where no rehearsals were reported, recall following visual presentation was best.
1023800
The neural bases of mental imagery
A cable clamp having jaws hingedly connected at one end by a hinge having a diametrical bore through which a cable can be inserted between the jaws, is energized by tension applied to the other ends of the jaws by a means acting to draw the jaws together into clamping engagement with a cable engaged between the jaws.
23602412
Scientific Utopia
An academic scientist’s professional success depends on publishing. Publishing norms emphasize novel, positive results. As such, disciplinary incentives encourage design, analysis, and reporting decisions that elicit positive results and ignore negative results. Prior reports demonstrate how these incentives inflate the rate of false effects in published science. When incentives favor novelty over replication, false results persist in the literature unchallenged, reducing efficiency in knowledge accumulation. Previous suggestions to address this problem are unlikely to be effective. For example, a journal of negative results publishes otherwise unpublishable reports. This enshrines the low status of the journal and its content. The persistence of false findings can be meliorated with strategies that make the fundamental but abstract accuracy motive—getting it right—competitive with the more tangible and concrete incentive—getting it published. This article develops strategies for improving scientific practices and knowledge accumulation that account for ordinary human motivations and biases.
18665006
Neural correlates of the essence of conscious conflict: fMRI of sustaining incompatible intentions
The study of intrapsychic conflict has long been central to many key theories about the control of behavior. More recently, by focusing on the nature of conflicting processes in the brain, investigators have revealed great insights about controlled versus automatic processes and the nature of self-control. Despite these advances, many theories of cognitive control or self-control remain agnostic about the function of subjective awareness (i.e., basic consciousness). Why people consciously experience some conflicts in the nervous system but not others remains a mystery. One hypothesis is that people become conscious only of conflicts involving competition for the control of skeletal muscle. To test one aspect of this larger hypothesis, in the present study, 14 participants were trained to introspect the feeling of conflict (the urge to make an error during a Stroop color-word interference task) and then were asked to introspect in the same way while sustaining simple compatible and incompatible intentions during fMRI scanning (to move a finger left or right). As predicted, merely sustaining incompatible skeletomotor intentions prior to their execution produced stronger systematic changes in subjective experience than sustaining compatible intentions, as indicated by self-report ratings obtained in the scanner. Similar ratings held for a modified Stroop-like task when contrasting incompatible versus compatible trials also during fMRI scanning. We use subjective ratings as the basis of parametric analyses of fMRI data, focusing a priori on the brain regions involved in action-related urges (e.g., parietal cortex) and cognitive control (e.g., dorsal anterior cingulate cortex, lateral PFC). The results showed that subjective conflict from sustaining incompatible intentions was consistently related to activity in the left post-central gyrus.
45486938
Neuronal correlates of subjective visual perception.
Neuronal activity in the superior temporal sulcus of monkeys, a cortical region that plays an important role in analyzing visual motion, was related to the subjective perception of movement during a visual task. Single neurons were recorded while monkeys (Macaca mulatta) discriminated the direction of motion of stimuli that could be seen moving in either of two directions during binocular rivalry. The activity of many neurons was dictated by the retinal stimulus. Other neurons, however, reflected the monkeys' reported perception of motion direction, indicating that these neurons in the superior temporal sulcus may mediate the perceptual experience of a moving object.
8226605
Neural correlates of thought suppression
The present report used functional magnetic resonance imaging (fMRI) to examine the neural correlates of thought suppression. Subjects were imaged while alternately (i) attempting to suppress a particular thought, (ii) attempting to suppress all thoughts, or (iii) thinking freely about any thought. Suppression of a particular thought, when compared to the free-thought control condition, revealed greater activation in the anterior cingulate. When the task of suppressing all conscious thoughts was compared to free-thought, a more distributed network of brain regions, including the anterior cingulate and the insula, was activated. These findings are consistent with previous research on cognitive control and may provide potential insights into psychological disorders involving recurring, intrusive thoughts.
14919848
Response to Comment on "Wandering Minds: The Default Network and Stimulus-Independent Thought"
Gilbert et al. suggest that activity in the default network may be due to the emergence of stimulus-oriented rather than stimulus-independent thought. Although both kinds of thought likely emerge during familiar tasks, we argue—and report data suggesting—that stimulus-independent thought dominates unconstrained cognitive periods.
7228673
Separating Sustained From Transient Aspects of Cognitive Control During Thought Suppression
Cognitive theories of how people regulate their thoughts have suggested the involvement of two control processes that occur over different time courses. These cognitive accounts parallel recent neural models of executive control, which suggest that the prefrontal cortex (PFC) mediates sustained changes in the allocation of control processes, whereas the anterior cingulate cortex (ACC) relays a transient need for additional control. Combining these cognitive and neural models of control, we used recently developed analysis techniques to distinguish transient from sustained changes in brain activation while subjects attempted to suppress an unwanted thought. Results were consistent with both models: Dorsolateral PFC demonstrated sustained increases in activation during attempts at thought suppression, whereas bilateral ACC demonstrated transient increases associated with occurrences of unwanted thoughts. These data support proposals regarding the different contributions made by the PFC and ACC to executive control and provide initial neuroimaging support for dual-process models of how individuals regulate their thoughts.