The discrimination of angry and fearful facial expressions in 7-month-old infants: An event-related potential study

The important ability to discriminate facial expressions of emotion develops early in human ontogeny. In the present study, 7-month-old infants’ event-related potentials (ERPs) in response to angry and fearful emotional expressions were measured. The angry face evoked a larger negative component (Nc) at fronto-central leads between 300 and 600 ms after stimulus onset when compared to the amplitude of the Nc to the fearful face. Furthermore, over posterior channels, the angry expression elicited a N290 that was larger in amplitude and a P400 that was smaller in amplitude than for the fearful expression. This is the first study that shows that the ability of infants to discriminate angry and fearful facial expressions can be measured at the electrophysiological level. These data suggest that 7-month-olds allocated more attentional resources to the angry face as indexed by the Nc. Implications of this result may be that the social signal values were perceived differentially, not merely as “negative”. Furthermore, it is possible that the angry expression might have been more arousing and discomforting for the infant compared with the fearful expression.