Unintentional and intentional recognition rely on dissociable neurocognitive mechanisms

Distractibility can lead to accidents and academic failures, as well as memory problems. Recent evidence suggests that intentional recognition memory can be biased by unintentional recognition of distracting stimuli in the same environment. It is unknown whether unintentional and intentional recognition depend on the same underlying neurocognitive mechanisms. We assessed whether human participants’ recognition of previously seen (old) or not seen (new) target stimuli was affected by whether a to-be-ignored distractor was old or new. ERPs were recorded to investigate the neural correlates of this bias. The results showed that the old/new status of salient distractors had a biasing effect on target recognition accuracy. Both intentional and unintentional recognition elicited early ERP effects that are thought to reflect relatively automatic memory processes. However, only intentional recognition elicited the later ERP marker of conscious recollection, consistent with previous suggestions that recollection is under voluntary control. In contrast, unintentional recognition was associated with an enhanced late posterior negativity, which may reflect monitoring or evaluation of memory signals. The findings suggest that unintentional and intentional recognition involve dissociable memory processes.