Nulsen C, Fox A, Hammond G. Electrophysiological indices of altered working memory processes in long-term ecstasy users.
Hum Psychopharmacol 2011;
26:488-97. [PMID:
21953632 DOI:
10.1002/hup.1231]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Accepted: 08/25/2011] [Indexed: 11/08/2022]
Abstract
OBJECTIVE
The aim of this study was to determine the effect of light long-term ecstasy consumption on verbal short-term and working memory and to identify the cognitive processes contributing to task performance.
METHOD
Electroencephalogram was recorded while ecstasy users (N = 11), polydrug users (N = 13), and non-users (N = 13) completed forward and backward serial recognition tasks designed to engage verbal short-term memory and verbal working memory, respectively.
RESULTS
All three groups displayed significantly lower digit-backward span than digit-forward span with ecstasy users displaying the greatest difference. The parietally distributed P3b was significantly smaller in the digits backward task than in the digits forward task in non-ecstasy-using controls. Ecstasy users did not show the reduced P3b component in the backward task that was seen in both non-ecstasy-using control groups.
CONCLUSIONS
Ecstasy users' performance was suppressed more by the concurrent processing demands of the working memory task than that of the non-ecstasy-using controls. Non-ecstasy-using controls showed differential event-related potential wave forms in the short-term and working memory tasks, and this pattern was not seen in the ecstasy users. This is consistent with a reduction in the cognitive resources allocated to processing in working memory in ecstasy users.
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