An ERP investigation into the strategic regulation of the fluency heuristic during recognition memory.

The goal of the present study was to determine whether masked repetition priming affects ERPs differently depending on whether or not participants are biased by task conditions to interpret enhanced perceptual fluency as evidence of prior study. Participants studied a list of words either in the visual modality or in the auditory modality and then performed a visual recognition memory test while ERPs were recorded. During the test, half the stimuli were preceded by a briefly presented matching prime word and half were preceded by a briefly presented non-matching prime word. Unlike in previous behavioral studies, masked repetition priming led to a reduction in positive recognition responses following auditory study, and had no effect following visual study, although post hoc analyses suggest that participants who received the visual study list may have relied on fluency to make some of their recognition decisions. Masked repetition priming also led to positive ERPs during two time windows-an early 300-500 ms window and a later 500-700 ms window. During the later time window, masked repetition priming exhibited a frontal scalp distribution that was most pronounced for participants who received the auditory study list. We suggest that this late frontal effect reflects participants' tendency to reject enhanced perceptual fluency as evidence of prior study.