DO CHRONIC-ALCOHOLICS HAVE INTACT IMPLICIT MEMORY - AN ERP STUDY

In order to investigate whether visual object priming differs from vis ual word priming and whether the visual repetition priming in chronic alcoholic patients is impaired, we performed an ERP study on 27 male c ontrol and 67 male alcoholic subjects. Sixty-one electrodes were emplo yed to record ERPs that were elicited by random presentations of objec t pictures, words, and scrambles for both pictures and words. We also used an implicit task that required subjects to identify whether each stimulus was recognizable. The current experiment revealed that (1) th e reaction times to both recognizable picture and word stimuli were si gnificantly shortened by the prior exposures of the same stimuli, (2) control subjects reflected visual object and word priming in different ERP components with different topographic patterns, (3) alcoholic sub jects manifested visual word priming in the same ERP component as cont rols, and (4) the differences in ERP components, both in amplitude and topographic distribution, between the two groups occurred mainly in t he different stimuli. These data suggest that the visual object and wo rd priming have distinctive neural processes. The visual object primin g in alcoholic subjects may be impaired while the visual word priming seemed to be intact. (C) 1997 Elsevier Science Ireland Ltd.