Department of Psychiatry and Biobehavioral Sciences, UCLA, Los Angeles, CA, USA.
Department of Psychology, University of Southern California, Los Angeles, CA, USA.
Psychiatry Res. 2011 Dec 30;194(3):287-295. doi: 10.1016/j.pscychresns.2011.04.010. Epub 2011 Nov 1.
Individuals who abuse methamphetamine (MA) perform at levels below those of healthy controls on tests that require cognitive control. As cognitive control deficits may influence the success of treatment for addiction, we sought to help clarify the neural correlates of this deficit. MA-dependent (n=10, abstinent 4-7 days) and control subjects (n=18) performed a color-word Stroop task, which requires cognitive control, during functional MRI (fMRI). The task included a condition in which participants were required to respond to one stimulus dimension while ignoring another conflicting dimension, and another condition without conflict. We compared the groups on performance and neural activation in the two conditions. MA-dependent subjects made more errors and responded more slowly than controls. Controlling for response times in the incongruent condition, voxel-wise mixed effects analyses (whole-brain corrected) demonstrated that MA-dependent subjects had less activation than control subjects in the right inferior frontal gyrus, supplementary motor cortex/anterior cingulate gyrus and the anterior insular cortex during the incongruent condition only. MA-dependent subjects did not exhibit greater activation in any brain region in either of the Stroop conditions. These preliminary findings suggest that hypofunction in cortical areas that are important for executive function underlies cognitive control deficits associated with MA dependence.
滥用甲基苯丙胺（MA）的个体在需要认知控制的测试中表现不如健康对照组。由于认知控制缺陷可能会影响成瘾治疗的成功，我们试图帮助阐明这种缺陷的神经相关性。MA 依赖者（n=10，戒断 4-7 天）和对照组（n=18）在功能磁共振成像（fMRI）期间执行了颜色-单词斯特鲁普任务，该任务需要认知控制。任务包括要求参与者响应一个刺激维度而忽略另一个冲突维度的条件，以及没有冲突的另一个条件。我们比较了两组在两种情况下的表现和神经激活。MA 依赖者比对照组犯的错误更多，反应也更慢。在不一致条件下控制反应时间，体素混合效应分析（全脑校正）表明，MA 依赖者在不一致条件下右侧额下回、辅助运动皮层/前扣带皮层和前岛叶皮层的激活程度低于对照组。MA 依赖者在斯特鲁普任务的任何一种情况下都没有表现出更大的大脑区域激活。这些初步发现表明，与 MA 依赖相关的认知控制缺陷的基础是与执行功能相关的皮质区域的功能低下。
