Bias toward drug-related stimuli is affected by loading working memory in abstinent ex-methamphetamine users

Research output: Contribution to journalArticlepeer-review

Authors

  • Zoha Deldar
  • Hamed Ekhtiari
  • Hamidreza Pouretemad
  • Ali Khatibi

Colleges, School and Institutes

External organisations

  • Institute for Cognitive Science Studies
  • Tehran University of Medical Sciences
  • Shahid Beheshti University

Abstract

Background: There is a trade-off between drug-related impulsive process and cognitive reflective process among ex-drug abusers. The present study aimed to investigate the impulsive effects of methamphetamine-related stimuli on working memory (WM) performance by manipulating WM load in abstinent ex-methamphetamine users.
Methods: Thirty abstinent ex-methamphetamine users and 30 nonaddict matched control participants were recruited in this study. We used a modified Sternberg task in which participants were instructed to memorize three different sets of methamphetamine-related and non–drug-related words (three, five, or seven words) while performing a secondary attention-demanding task as an interference.
Results: Repeated-measures ANOVA revealed that reaction times of abstinent ex-methamphetamine users increased during low WM load (three words) compared to the control group (p = 0.01). No significant differences were observed during high WM loads (five or seven words) (both p’s > 0.1). Besides, reaction times of the experimental group during trials with high interference (three, five, or seven words) were not significantly different compared to the control group (p > 0.2).
Conclusion: These findings imply that increasing WM load may provide an efficient buffer against attentional capture by salient stimuli (i.e., methamphetamine-related words). This buffer might modify the effect of interference bias. Besides, presenting methamphetamine-related stimuli might facilitate the encoding phase due to bias toward task-relevant stimuli. This finding has an important implication, suggesting that performing concurrent demanding tasks may reduce the power of salient stimuli and thus improve the efficiency of emotional regulation strategies.

Details

Original languageEnglish
Article number776
Pages (from-to)1-13
Number of pages13
JournalFrontiers in Psychiatry
Volume10
Publication statusPublished - 22 Oct 2019

Keywords

  • addiction, dual-process models, working memory bias, working memory interference bias, working memory capacity, abstinent ex-methamphetamine users