Center of Functionally Integrative Neuroscience, Aarhus University, 8000 Aarhus, Denmark.
Proc Natl Acad Sci U S A. 2013 Mar 19;110(12):4744-9. doi: 10.1073/pnas.1302374110. Epub 2013 Mar 4.
The introduction of magnetoencephalography has made it possible to study electromagnetic signaling in deeper, paralimbic cortical structures such as the medial prefrontal/anterior cingulate (ACC) and medial parietal/posterior cingulate (PCC) cortices. Self-awareness and self-control have been attributed to these regions. To test the hypothesis that they are dysfunctional in pathological gambling with poor self-control, we studied gamblers with and without previous stimulant abuse and age- and sex-matched controls. We found that pathological gamblers were more impulsive than controls in a stop-signal task and attributed this to changes in the activity of the paralimbic network: Pathological gamblers had reduced synchronization at rest in the high gamma range (55-100 Hz) compared with controls and failed to show an increase in gamma synchronization during rest compared with the task, as observed in controls. Subgroup analysis revealed that pathological gamblers without a history of stimulant abuse had lower PCC power during the stop-signal task compared with controls and gamblers with previous stimulant abuse. Furthermore, gamblers with a history of stimulant abuse had up to four times higher power at the ACC site during rest and the task compared with controls. In conclusion, pathological gamblers had higher impulsivity and functional paralimbic abnormalities, which could not be explained by a history of stimulant abuse. In addition, previous stimulant abuse had a marked effect on the amplitude of oscillatory brain activity in the ACC and PCC, suggesting long-term deleterious effects of repeated dopaminergic drug exposure. These consequences should be investigated in more detail in longitudinal studies.
脑磁图的引入使得研究更深层次的电磁信号成为可能，如边缘皮层结构中的内侧前额叶/前扣带（ACC）和内侧顶叶/后扣带（PCC）皮质。自我意识和自我控制被归因于这些区域。为了检验这些区域在病理性赌博和自我控制能力差中存在功能障碍的假设，我们研究了有或没有既往兴奋剂滥用史的赌徒以及年龄和性别匹配的对照组。我们发现，在停止信号任务中，病理性赌徒比对照组更冲动，并将其归因于边缘网络活动的变化：与对照组相比，病理性赌徒在静息状态下的高伽马频段（55-100Hz）的同步性降低，并且在静息状态下没有表现出与对照组相比在任务中伽马同步性增加。亚组分析显示，与对照组相比，无兴奋剂滥用史的病理性赌徒在停止信号任务中的 PCC 功率较低，而有兴奋剂滥用史的赌徒则较高。此外，与对照组相比，有兴奋剂滥用史的赌徒在静息和任务期间的 ACC 部位的功率高达四倍。总之，病理性赌徒的冲动性更高，边缘功能异常，这不能用兴奋剂滥用史来解释。此外，既往兴奋剂滥用对 ACC 和 PCC 中的脑振荡活动幅度有显著影响，提示反复多巴胺药物暴露的长期有害影响。这些后果应在纵向研究中进行更详细的研究。
