Enactment and bizarreness modulate familiarity and recollection in associative recognition: Evidence from FN400 and...

Individuals usually have superior memory for bizarre stimuli compared to common ones. However, the extent to which bizarreness influences memory for actions remains unclear. Recent evidence has shown that performed actions represented by an action phrase (verb-object pair) in subject-performed task (SPT) result in better associative memory than simply reading it in verbal task (VT). Here, we directly investigated the effect of bizarreness on associative memory for action components following SPT relative to VT and its underlying memory processes using EEGs. During studying, the participants studied ordinary and bizarre verb-object phrases (pairs) in an SPT or VT condition. During testing, they discriminated between intact, recombined, and new pairs. Behaviorally, associative recognition of verb-object phrases was better following SPT than VT for ordinary and bizarre phrases. Bizarreness improved associative recognition under VT (but not SPT). In the event related potentials (ERP), an early frontal old-new effect (FN400) for intact vs. new pairs was observed under SPT for ordinary and bizarre phrases, whereas for VT, this effect was only observed for bizarre phrase. The FN400 for intact vs. recombined pairs was only present under SPT for ordinary phrases. In the late time window, a parietal old-new effect (LPC) for intact vs. new pairs was obtained under all conditions. The LPC for intact vs. recombined pairs only occurred under VT for bizarre phrases. These results demonstrate that enactment and bizarreness enhance associative recognition through distinct mechanisms by differentially modulating the contributions of familiarity and recollection during retrieval of action-object associations.