Brain potentials reflect behavioral differences in true and false recognition

People often falsely recognize nonstudied lures that are semantically simil ar to previously studied words. Behavioral research suggests that such fals e recognition is based on high semantic overlap between studied items and l ures that yield a feeling of familiarity, whereas true recognition is more often associated with the recollection of details. Despite this behavioral evidence for differences between true and false recognition, research measu ring brain activity (PET, fMRI, ERP) has not clearly differentiated corresp onding differences in brain activity. A median split was used to separate s ubjects into Good and Poor performers based on their discrimination of stud ied targets from similar lures. Only Good performers showed late (1000-1500 msec), right frontal event-related brain potentials (ERPs) that were more positive for targets and lures compared with new items. The right frontal d ifferences are interpreted as reflecting postretrieval evaluation processes that were more likely to be engaged by Good than Poor performers. Both Goo d and Poor performers showed a parietal ERP old/new effect (400-800 msec), but only Poor performers showed a parietal old/lure difference. These resul ts are consistent with the view that the parietal and frontal ERP old/new e ffects reflect dissociable processes related to recollection.