ERP responses to the Recognition of ambiguous facial expressions

Abstract

An event-related brain potential (ERP) study investigated how different processing stages involved in categorization of facial expression are reflected by ERP modulations, and how ambiguity of facial expressions influence such effects. ERPs were recorded in response to facial expressions in which ambiguity was controlled by morphing techniques. Fifteen participants labeled positive or negative emotion expressed by face. The labeling task was a forced choice two categories. Each trial lasted 6.5s (0.5s of presentation, followed by a 6s interval of scrambled faces).
The ambiguous expression gave rise to N480 ms component with frontocentral and bilateral temporal electrodes; the onset of N480 component was much later in temporal than frontcentral. These findings suggest that activity in both frontocentral and temporal region vary with ambiguity of facial expressions in the categorization process.