Abstract
Does the early perceptual processing of faces flexibly adapt to the requirements of the categorization task at hand, or alternatively does it operate independently of this cognitive context? Behavioral studies have shown that visual information such as the fine and coarse scales of a face are differentially processed depending on the categorization task performed, thus suggesting that the latter can influence stimulus perception. Here, we investigated the early vs. late influence of task effects on perceptual processing by examining visual event-related potentials (ERPs P100 and N170) reflecting the activity of early vision, while observers categorized faces for their gender and familiarity. Stimuli were full spectrum, or filtered versions of the faces that preserved either their coarse or fine scale information. Behavioral results replicated previous findings of a differential processing of coarse and fine spatial scales across tasks. In addition, ERPs revealed a modulation of the P100, which was enlarged for the familiarity task, suggesting an increased visual analysis subtending this more stringent categorization. Familiarity also decreased the amplitude of the N170, but only for coarse scale faces. These results suggest that the task of categorizing an identical face according to its familiarity or gender modulates the early visual processing of spatial scales.