Older adults demonstrate greater susceptibility to high-confidence memory distortions. Cognitive processes underlying memory errors in older adults remain unclear. Here, in a categorized pictures paradigm, we used the event-related potential (ERP) to examine the electrophysiological correlates of false recognition. Young and older participants were presented with categorized pictures during study and subsequently completed an old/new recognition memory task that included studied pictures, lure pictures from studied categories, and new pictures. Behavioral results showed proportionally similar but higher-confidence false memories in older adults compared to young adults. ERP results revealed that false recognition elicited a significant early frontal old/new effect indexing familiarity in young adults, while older adults exhibited a reliable late posterior negativity during false recognition. These findings suggest that episodic reconstruction contributes to high-confidence false memories in older adults.