RESULTS

Figure 2 shows, at a subset of anterior and posterior electrodes, the grand mean ERPs elicited by non-target faces averaged across the age ranges for all discrimination tasks (No-discrimination, Incidental-age, Intentional-age and Intentional-gender discrimination). At posterior electrode sites, the responses are characterized by the positive ’P100 component’ peaking around 100 msec at O1-O2, and the negative ’N170 component’ maximum around 150 msec at T5-T6. These deflections are followed by a positive peak around 240 msec, and a sustained positivity lasting up to the stimulus offset deflection around 400 msec at posterior sites (P13-P24 and T5-T6). The shaded rectangles indicate the time periods when the ERP responses elicited in the No-discrimination task differ from those elicited in age or gender discrimination tasks.