Contributions of surface and conceptual information to performance on implicit and explicit memory tasks.

Four experiments examined the effects of perceptual and conceptual processing operations on 2 implicit and 2 explicit memory tasks. Results show an advantage of visual over auditory presentation for word-fragment completion, word-stem completion, and word-stem cued recall; there was no such advantage in recognition memory. Conceptual processing had no effect on the implicit tasks, a small effect on word-stem cued recall, and a large effect on recognition. It is concluded that there is no necessary trade-off between the 2 types of information. Speculatively, the use of perceptual information may be all or none and relatively automatic, whereas the use of conceptual information appears to be graded and more under conscious control.