Target similarity effects: Support for the parallel distributed processingassumptions

Recent research has begun to provide support for the assumptions that memor ies are stored as a composite and are accessed in parallel (Tehan & Humphre ys, 1998). New predictions derived from these assumptions and from the Chap pell and Humphreys (1994) implementation of these assumptions were tested. In three experiments, subjects studied relatively short lists of words. Som e of the Lists contained two similar targets (thief and theft) or two dissi milar targets (thief and steal) associated with the same cue (ROBBERY). AS predicted, target similarity affected performance in cued recall but not fr ee association. Contrary to predictions, two spaced presentations of a targ et did not improve performance in free association. Two additional experime nts confirmed and extended this finding. Several alternative explanations f or the target similarity effect, which incorporate assumptions about separa te representations and sequential search, are rejected. The importance of t he finding that, in at least one implicit memory paradigm, repetition does not improve performance is also discussed.