Jansen Jochem M, van Holst Ruth J, van den Brink Wim, Veltman Dick J, Caan Matthan W A, Goudriaan Anna E
Academic Medical Centre, Department of Psychiatry, Amsterdam Institute for Addiction Research, The Netherlands.
Donders Institute for Cognition, Brain and Behaviour, Radboud University, The Netherlands.
Addict Biol. 2015 Sep;20(5):979-89. doi: 10.1111/adb.12199. Epub 2014 Dec 5.
Cognitive flexibility has been associated with prefrontal white matter (WM) integrity in healthy controls (HCs), showing that lower WM integrity is associated with worse performance. Although both cognitive flexibility and WM integrity have been found to be aberrant in alcohol-dependent (AD) patients, the relationship between the two has never been tested. In this study, we investigated the association between WM tract density and cognitive flexibility in patients with AD (n = 26) and HCs (n = 22). In order to assess the influence of AD severity, we also included a group of problematic drinkers (PrDs; n = 23) who did not meet the AD criteria. Behavioral responses and brain activity during a cognitive flexibility task were measured during functional magnetic resonance imaging. Probabilistic fiber tracking was performed between the dorsolateral prefrontal cortex and the basal ganglia; two crucial regions for task switching. Finally, the task-related functional connectivity between these areas was assessed. There were no significant group differences in the task performance. However, compared with HCs, AD patients and PrDs showed decreased WM integrity and increased prefrontal brain activation during task switching. Evidence is presented for a compensatory mechanism, involving recruitment of additional prefrontal resources in order to compensate for WM and neural function impairments in AD patients and PrDs. Although present in both alcohol groups, the PrDs were more successful in invoking this compensatory mechanism when compared to the AD patients. We propose that this may therefore serve as a protective factor, precluding transition from problematic drinking into alcohol dependence.
在健康对照者（HCs）中，认知灵活性与前额叶白质（WM）完整性相关，表明WM完整性越低，表现越差。尽管在酒精依赖（AD）患者中发现认知灵活性和WM完整性均异常，但两者之间的关系从未得到检验。在本研究中，我们调查了AD患者（n = 26）和HCs（n = 22）中WM束密度与认知灵活性之间的关联。为了评估AD严重程度的影响，我们还纳入了一组不符合AD标准的问题饮酒者（PrDs；n = 23）。在功能磁共振成像期间测量认知灵活性任务中的行为反应和大脑活动。在背外侧前额叶皮层和基底神经节之间进行概率纤维追踪；这是任务切换的两个关键区域。最后，评估这些区域之间与任务相关的功能连接性。任务表现方面没有显著的组间差异。然而，与HCs相比，AD患者和PrDs在任务切换期间显示出WM完整性降低和前额叶大脑激活增加。有证据表明存在一种代偿机制，即AD患者和PrDs会募集额外的前额叶资源以补偿WM和神经功能损伤。尽管在两个酒精组中都存在这种情况，但与AD患者相比，PrDs在调用这种代偿机制方面更成功。我们提出，这可能因此作为一种保护因素，防止从问题饮酒转变为酒精依赖。
