Abstract
Functional magnetic resonance imaging (fMRI) is. a new method to investigate the neural substrates that underlie the psychological process in human and to test and expand the hypothesis of the affective psychological models. First, the present paper surveys the brief history of the neural imaging technique and physiological backgrounds of fMRI. Next, focusing on the neural imaging studies that examined the processing of facial expression, function of the amygdala playing an important role to evaluate the emotional valence of perceived stimuli is discussed according to it's laterality. There is also a review of the studies that investigated the processing of classification of facial expression into emotional categories using fMRI and an event-related brain potential (ERP) measurement. It seems to be important to note that the both frontal and temporal region underlies the categorization process, and the onset of ERP component that was presumed to reflect the categorization process is much later of temporal than frontal. Based on these findings, a new model on the processing of facial expression is suggested that describes emotional categorizing process is achieved by front-temporal network. Finally, future direction of the affective psychological studies is discussed on this topic.
