The concreteness effect in implicit and explicit memory tests

Four experiments were conducted to examine the concreteness effect ill implicit and explicit memory measures. Experiment 1 replicated prior reports of an imagery effect on an implicit conceptual memory test. In Experiment 2. we confirmed our prediction of conceptual sensitivity of free recall, explicit general knowledge, explicit word fragment completion, and the implicit general knowledge tests with a levels of processing manipulation. Furthermore, although we obtained the concreteness effect (better memory for concrete than abstract nouns) in free recall and we explicit general knowledge test, we failed to find this effect in the implicit general knowledge test. Experiment 3 revealed that the failure to iind the concreteness effect on the implicit general knowledge test was not attributable to combining two encoding manipulations in Experiment 2. In Experiment 4. we ruled out the possibility that the failure to find the concreteness effect in conceptual implicit memory may be related to the number of meaningful associates for targets, We discuss the implications of these findings within the context of the transfer appropriate processing framework (Roediger, Weldon, & Challis, 1989) and the dual-code hypothesis (Paivio, 1971, 1991) of memory. (C) 2001 Academic Press.