Transfer across modality in perceptual implicit memory.

We examined whether words studied in one modality (visual or auditory) would prime performance in the opposite modality in five different perceptual implicit memory tests: auditory perceptual identification, auditory stem completion, visual perceptual identification, visual stem completion, and visual fragment completion. Significant transfer across modality was observed in all five tasks. However, a large proportion of the subjects reported using explicit retrieval strategies during the implicit tests. Those subjects who claimed not to have used explicit retrieval processes during the test phase demonstrated transfer across modalities in the stem completion tests and the perceptual identification tests, but not in the fragment completion test. The results indicate that implicit visual word-fragment completion is unique, in the sense that it relies exclusively on perceptual memory processes, whereas the other tasks rely, in part, on nonperceptual memory processes.