Human facial expressions are important social signals conveying emotions, and have been used extensively in emotion research. A large literature on the psychology of facial emotion processing is now complemented by lesion and functional imaging studies from cognitive neuroscience. However, we still lack a detailed understanding of the anatomical and temporal components of such processing: what brain regions are engaged at various points in time, and what cognitive processes do they participate in? The goal of our research is to understand the functional organizations of those areas of human cerebral cortex that are engaged in processing emotional facial expressions, and to examine how facial expression is represented within these regions. These experiments involve direct electrophysiological recording from the cerebral cortex of awake human subjects undergoing clinical evaluation for intractable epilepsy. In the course of our investigations we plan to identify the cortical regions within temporal, parietal, and frontal lobes that are differentially engaged in processing emotional facial expressions. Subjects will be shown faces, and morphs of faces, that vary in terms of the emotion shown. Recordings obtained from intracranial grid electrodes will be analyzed in terms of the emotion shown on the face stimulus, and the location at which the recording was obtained. The research will be carried out in the context of a multidisciplinary team investigating the neurophysiology of human cognition. Findings from this research will complement data obtained from functional imaging and lesion studies in humans, which lack the spatiotemporal resolution of direct electrical recordings, and can also be compared to electrophysiological studies efface processing and emotion in nonhuman primates. They thus constitute a critical set of data that will help to construct detailed causal theories of emotional information processing in the brain. The studies will also be of value in guiding the diagnosis, management, and treatment of patients with dysfunction of emotion and face processing, such as those suffering from various psychiatric disorders or focal lesions. By providing us with a better basic understanding of how emotional stimuli are processed by the human brain, the proposed studies will inform not only pathologies of emotion, but also help elucidate individual differences in emotion processing in normal individuals.