Aberrant Reward Anticipating and Processing in Abstinent Heroin Addicts

Drug addicts have a strong desire for immediate reward, which are characterized by difficulty in controlling drug use. Whether chronic heroin intake impairs the reward-circuit function and behavioral regulation when confronted with monetary incentives is currently unknown. Thus, the present study explored the prospects of delayed reward by combining event-related potentials (ERPs) and standardized low-resolution brain electromagnetic tomography analyses (sLORETA). Behavioral and electroencephalography (EEG) data were collected from 23 abstinent heroin addicts (AHAs) and 23 age-, education-, and gender-matched healthy controls (HCs). We found that AHAs responded more quickly to monetary incentives compared with HCs across all conditions. AHAs exhibited a disappearing right hemisphere predominance of stimulus-preceding negativity (SPN) and a higher feedback-related negativity (FRN) compared to HCs. Moreover, sLORETA results showed AHAs had significant reduced activities in superior/medial frontal gyrus (SFG/MFG) at the cue detection stage and in superior temporal gyrus (STG) and insula at the reward anticipation stages, as well as in precuneus, anterior/posterior cingulate cortex (ACC and PCC), para-hippocampal gyrus (PHG), middle/inferior temporal gyrus (MTG/ITG), inferior parietal lobe (IPL), and SFG at the outcome notification stage, respectively, relative to HCs. Our findings revealed abnormalities in reward-related brain regions of AHAs, which further result in the insensitivity to potential punishments and deficits in impulsive control. This study contributes to the understanding of the neural basis of reward anticipation and processing by AHAs and provides a basis for further withdrawal treatment.