Implicit processing of heroin and emotional cues in abstinent heroin users: early and late event-related potential effects

Abstract

Background: The abnormal cognitive processing of drug cues is a core characteristic of drug dependence. Previous research has suggested that the late positive potential (LPP) of heroin users is increased by heroin-related stimuli because of the attention-grabbing nature of such stimuli. Objectives: The present research used a modified emotional Stroop (eStroop) task to examine whether there was an early posterior negativity (EPN) modulation to heroin cues compared with emotional or neutral stimuli in heroin dependent subjects. Methods: Fifteen former heroin users and 15 matched controls performed the eStroop task, which was composed of positive, negative, heroin-related, and neutral pictures with superimposed color squares. Participants responded to the color of the square and not to the picture while behavioral data and event-related potentials were recorded. Results: There were no significant differences of EPN amplitudes to emotional and neutral stimuli between heroin users and controls. However, heroin users displayed increased EPN modulation for heroin cues, whereas this modulation was absent in controls. Conclusions: Drug-related cues acquire motivational salience and automatically capture the attention of heroin users at early processing stages, even when engaged in a non-drug-related task. The EPN to heroin cues could represent a novel electrophysiological index with clinical implications for selecting abstinent drug users who are at increased risk of relapse or to evaluate treatment interventions.

• Attentional bias
• early posterior negativity (EPN)
• event-related potentials (ERP)
• heroin dependence
• late positive potential (LPP)

Acknowledgements

We gratefully acknowledge the valuable cooperation of Renqian Xie (Dean of the Gansu province Lanzhou city Addiction Recovery Center) and Weixiang Di (and the members of her laboratory) in preparing this study.

Funding

This study was supported by grants (31360233, 31300838) from National Natural Science Foundation of China.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.