Modulation of the N170 adaptation as a function of individual differences in face ability

We used a rapid neural adaptation procedure and the Event Related Potential technique in order to study the electrophysiological correlates of individual differences in face ability. In the first session of the study using the Cambridge Face Memory Test different groups of face performers selected on the basis of their low, average or high face ability were identified. Subjects whose scores fell within one SD below the mean were classified as Bad recognizers, whereas those that fell within one SD above the mean were classified as Good recognizers; subjects inside the mean range were classified as Average recognizers. In the second session, ERPs were recorded during a same/different identity-task with the procedure of the rapid visual adaptation. The amplitude reduction of N170 for the test stimuli compared to the adaptor stimuli indexed the adaptation effect. A modulation of neural activity emerged as a function of the individual differences. Specifically, the face-specific N170 component showed the adaptation effect according to the different groups of face performers but, as the main interesting result, good recognizers showed a decreased amplitude of N170 for test face same identity compared to test face different identity indicating a very sensitive mechanism for face individuation. These results exhibit that individual differences in face recognition might influence the ERP patterns and that the N170 is a suitable and sensitive tool to tap into these variable abilities. All in all, we suggest that the specific brain activity that is involved in face recognition is highly influenced by individual differences.