Event-related potentials during learning and recognition of complex pictures

grantor: University of TorontoEvent-related potentials (ERPs) were recorded while subjects learned a large set of complex, coloured pictures. Recognition memory was examined within the same day and after a 24 hour lag. Memory performance decreased from 88% to 65% over 24 hours. The ERP waveforms showed a prominent parietal-occipital P100-N150-P240 complex that was the same in learning and recognition. A centro-parietal P650 wave was larger during recognition than during learning for both the new and old pictures. During learning the pictures elicited a sustained positive potential maximally recorded in the occipital regions. Finally, in the recognition condition, new pictures elicited an N400 wave over frontal electrodes while old pictures elicited an earlier centroparietal P650 than novel pictures. Learning is most clearly associated with a sustained occipital positivity, recognition with a parietal positive wave, and novelty-detection with a frontal negative wave.M.A