Few investigators have applied the working memory theory to studies on
abstinent chronic alcoholics, though it has been reported that the de
ficits in short-term memory appear to be specific to visuo-spatial and
problem-solving tasks. In the present study, we recorded ERPs from 40
male control subjects and 78 alcoholics performing a modified delayed
matching to sample task. To minimize the possible confound of retinot
opic projections for the matching stimuli, in contrast to the non-matc
hing stimuli, we employed a unique set of stimuli in our delayed match
ing to sample task. Our results indicate that an ERP component, occurr
ing at approximately 250 ms post-stimulus, may be a reflection of the
ERP mnemonic effect for working memory. This component distinguishes t
he two groups at the right occipitotemporal region, providing evidence
of right hemisphere dysfunction in alcoholics. Thus, the current expe
riment may show electrophysiological evidence of working memory defici
ts in alcoholics. (C) 1997 Elsevier Science Ireland Ltd.