Neural correlates of encoding in an incidental paradigm I

Srmrmer_v Event-related brain potentials (ERPs) werc recorded during an incidental lcarning paradigm. Recall and recognition were better for words inir ial ly presented in tasks requir ing semantic decisions ( i .e.. ' is i t l iv ing?'or ' is i t edible?') than for words in tasks rer;uiring non-semantic decisions. ERPs elicited during performance of thesc tasks were predictive of subsequent memory performance. A late positive ERP elicited by words later recalled or recognized was larger than that elicitcd by words later forgotten. This enhanced positivity for to-be-remembered words could be accounted for, in part. by the fact that words in scmanlic tasks were remembcred better and elicited larger ERPs than did words in non-scmantic tasks. Similarly, words followed by affirmative rathcr than negative decisions wcre associated both with better recognition and with larger ERPs. Howevcr. ERPs wcre scnsitive to proccsscs that influenced later memory performance even within an individual semantic task and within the affirmative decision condition. ln addition. results showed that the ERP differenccs based on later memory performance did not necessarily arise from amplitude variation in P3 waves that occurred at the same time.