The distinctiveness effect in the absence of conscious recollection: Evidence from conceptual priming

We tested whether the distinctiveness effect in memory (superior memory for isolated or unusual items) only occurs with conscious recollection or could emerge with recapitulation of the type of processing that occurred at study even in the absence of recollection at test. Participants studied lists of categorically isolated exemplars. In Experiment 1, participants received either an explicit or an implicit test of category verification. We hypothesized that this task would recapitulate the evaluative processing from study. Results showed better explicit category cued recognition as well as greater priming for isolated items than nonisolated items on a category verification test. The latter outcome suggests that the distinctiveness effect can occur in the absence of conscious recollection. In Experiment 2, we sought converging evidence for our hypothesis that reinstating the evaluative process is critical for obtaining the effect on the implicit test; we used another conceptual implicit memory test (category production) that contained matching test cues but did not require evaluative processing. The absence of a distinctiveness effect on this measure in conjunction with its presence on the implicit category verification measure suggests that evaluative processing mediates the distinctiveness effect.