McKim Theresa H, Bauer Daniel J, Boettiger Charlotte A
University of North Carolina.
J Cogn Neurosci. 2016 Jul;28(7):1024-38. doi: 10.1162/jocn_a_00953. Epub 2016 Mar 11.
Learned habitual responses to environmental stimuli allow efficient interaction with the environment, freeing cognitive resources for more demanding tasks. However, when the outcome of such actions is no longer a desired goal, established stimulus-response (S-R) associations or habits must be overcome. Among people with substance use disorders (SUDs), difficulty in overcoming habitual responses to stimuli associated with their addiction in favor of new, goal-directed behaviors contributes to relapse. Animal models of habit learning demonstrate that chronic self-administration of drugs of abuse promotes habitual responding beyond the domain of compulsive drug seeking. However, whether a similar propensity toward domain-general habitual responding occurs in humans with SUDs has remained unclear. To address this question, we used a visuomotor S-R learning and relearning task, the Hidden Association between Images Task, which employs abstract visual stimuli and manual responses. This task allows us to measure new S-R association learning and well-learned S-R association execution and includes a response contingency change manipulation to quantify the degree to which responding is habit-based, rather than goal-directed. We find that people with SUDs learn new S-R associations as well as healthy control participants do. Moreover, people with an SUD history slightly outperform controls in S-R execution. In contrast, people with SUDs are specifically impaired in overcoming well-learned S-R associations; those with SUDs make a significantly greater proportion of perseverative errors during well-learned S-R replacement, indicating the more habitual nature of their responses. Thus, with equivalent training and practice, people with SUDs appear to show enhanced domain-general habit formation.
对环境刺激的习得性习惯反应有助于与环境进行有效互动，从而将认知资源解放出来用于更具挑战性的任务。然而，当此类行为的结果不再是期望的目标时，就必须克服已建立的刺激-反应（S-R）关联或习惯。在患有物质使用障碍（SUD）的人群中，难以克服与成瘾相关的对刺激的习惯性反应，转而采取新的、目标导向行为，这会导致复发。习惯学习的动物模型表明，长期自我给药滥用药物会促进习惯性反应，超出强迫性觅药的范畴。然而，患有SUD的人类是否也存在类似的对领域通用习惯性反应的倾向仍不清楚。为了解决这个问题，我们使用了一种视觉运动S-R学习和再学习任务，即图像任务中的隐藏关联任务，该任务采用抽象视觉刺激和手动反应。这个任务使我们能够测量新的S-R关联学习以及熟练掌握的S-R关联执行情况，并包括一个反应偶然性变化操作，以量化反应基于习惯而非目标导向的程度。我们发现，患有SUD的人与健康对照参与者一样能够学习新的S-R关联。此外，有SUD病史的人在S-R执行方面略优于对照组。相比之下，患有SUD的人在克服熟练掌握的S-R关联方面存在特定障碍；患有SUD的人在熟练掌握的S-R替换过程中出现持续性错误的比例显著更高，这表明他们的反应更具习惯性。因此，在经过同等训练和练习后，患有SUD的人似乎表现出增强的领域通用习惯形成。
