ELECTROPHYSIOLOGICAL EVIDENCE OF MEMORY IMPAIRMENT IN ALCOHOLIC PATIENTS

In a series of event-related potential (ERP) studies, we have consiste ntly demonstrated an ERP component correlate of visual short-term memo ry, There have been frequent reports on the deficits of information en coding, retention, and retrieval in chronic alcoholics. In the present study, we investigated that the ERP mnemonic effects could be influen ced by long-term alcohol abuse. ERP data were recorded from 48 control s and 77 alcoholics while the subjects performed a modified delayed ma tching to sample paradigm using a series of object pictures as stimuli . The alcoholics completed the task with more errors and longer respon se times than the controls. The major differences in the evoked potent ials between the two groups are found at the temporo-occipital and fro ntal regions in the sample and nonmatching trials, and mostly prominen t in the right hemisphere. The current study indicates that the ERP te chnique can be a useful tool to index short-term memory, The ERP mnemo nic effect difference between the two groups may be a reflection of a working memory deficit caused by long-term alcohol abuse. Our data als o suggest right hemisphere dysfunction in alcoholics, with deficits in information encoding. (C) 1997 Society of Biological Psychiatry.