Event-related potentials to unfamiliar faces in a recognition memory task

摘要

The purpose of this study was to investigate electrophysiological correlates related to the recognition of repeated faces in the intact human by means of event-related potentials (ERPs), Twenty young healthy adults (mean, 24.5 years) performed a continuous face recognition task, in which unfamiliar faces were flashed upon a computer screen. Some faces were repeated immediately after initial presentation (at lag 0), while others were repeated after one intervening face (at lag 1) or at lag 3. Subjects were requested to push a button with the right thumb upon first presentation of a face and with a left thumb upon repeat presentation. Significant differences were seen in accuracy of new/old responses between at lag 0 and at lags 1 or 3. Reaction time (RT) for faces repeated at lag 0 was significantly shorter than that for first (new) presentations. RT at lag 3, however, was longer than RT for new faces. The ERPs recorded from 7 scalp sites revealed more positive going waveforms beginning at about 200 ms (old/new effect) for the correctly classified repeated faces. The ERP old/ new effects were more marked in anterior sites and were more prominent at lag 0 than at lags 1 and 3, It is thus concluded that the ERP old/new effect is demonstrated to unfamiliar faces and varies with repetition interval and scalp regions In addition, some discrepancy was found between electrophysiological and behavioral priming effects.