Previous studies identified cerebral markers of response inhibition dysfunction in cocaine dependence. However, whether deficits in response inhibition vary with the severity of cocaine use or ameliorate during abstinence remain unclear. This study aimed to address these issues and the neural mechanisms supporting the individual variation. We examined the data of 67 individuals with cocaine dependence (CD) and 84 healthy controls (HC) who underwent functional magnetic resonance imaging during a stop-signal task (SST). The stop-signal reaction time (SSRT) was computed using the integration method, with a longer SSRT indicating poorer response inhibition. The results showed that, while CD and HC did not differ significantly in SSRT, years of cocaine use (YOC) and days of abstinence (DOA) were each positively and negatively correlated with the SSRT in CD. Whole-brain regressions of stop minus go success trials on SSRT revealed correlates in bilateral superior temporal gyrus (STG) in response inhibition across CD and HC. Further, mediation and path analyses revealed that YOC and DOA affected SSRT through the STG activities in CD. Together, the findings characterized the contrasting effects of cocaine use severity and abstinence on response inhibition as well as the neural processes that support these effects in cocaine dependence.

先前的研究发现了可卡因依赖中反应抑制功能障碍的大脑标志物。然而，反应抑制的缺陷是否随着可卡因使用的严重程度而变化，或者在戒断期间是否有所改善仍不清楚。本研究旨在解决这些问题以及支持个体差异的神经机制。我们检查了 67 名可卡因依赖者 (CD) 和 84 名健康对照者 (HC) 的数据，他们在停止信号任务 (SST) 期间接受了功能性磁共振成像。使用积分方法计算停止信号反应时间（SSRT），SSRT 越长表明反应抑制越差。结果显示，虽然 CD 和 HC 在 SSRT 方面没有显着差异，但 CD 中可卡因使用年限 (YOC) 和戒断天数 (DOA) 分别与 SSRT 呈正相关和负相关。SSRT 成功试验的全脑回归揭示了双侧颞上回 (STG) 与 CD 和 HC 反应抑制的相关性。此外，中介和路径分析表明，YOC 和 DOA 通过 CD 中的 STG 活动影响 SSRT。总之，这些发现描述了可卡因使用严重程度和戒断对反应抑制的对比影响，以及支持可卡因依赖中这些影响的神经过程。