Objectives: A pre-conscious auditory sensory (echoic) memory of about 10 s
duration can be studied with the event-related brain potential mismatch neg
ativity (MMN). Previous work indicates that this memory is preserved in abs
tinent chronic alcoholics for a duration of up to 2 s. The authors' aim was
to determine the integrity of auditory sensory memory as indexed by MMN in
chronic alcoholism, when this memory has to be functionally active for a l
onger period of time.
Methods: The presence of MMN for stimuli that differ in duration was tested
at memory probe intervals (MPIs) of 0.4 and 5.0 s in 17 abstinent chronic
alcoholic patients and in 17 healthy age-matched control subjects.
Results: MMN was similar in alcoholics and controls when the MPI was 0.4 s,
whereas MMN could not be observed in the patients when the MPI was increas
ed to 5.0 a.
Conclusions: These results provide evidence of an impairment of auditory se
nsory memory in abstinent chronic alcoholics, whereas the automatic stimulu
s-change detector mechanism, involved in MMN generation, is preserved. (C)
2001 Elsevier Science Ireland Ltd. All rights reserved.