University of Bonn, Germany.
Cogn Affect Behav Neurosci. 2011 Dec;11(4):644-51. doi: 10.3758/s13415-011-0058-6.
The adjustment of behavior to changing goals and environmental constraints requires the flexible switching between different task sets. Cognitive flexibility is an endophenotype of executive functioning and is highly heritable, as indicated by twin studies. Individual differences in global flexibility as assessed by reaction-time measurement in a task-switching paradigm were recently related to a single nucleotide polymorphism in the vicinity of the dopamine d2 receptor gene DRD2. In the present study, we assessed whether the DRD2 gene is related to backward inhibition, a control mechanism that contributes to cognitive flexibility by reducing proactive interference by no longer relevant task sets. We found that carriers of the DRD2 A1+ variant who have a lower striatal dopamine d2 receptor density than A1- carriers show a larger backward inhibition effect. This is in line with previous results demonstrating increased behavioral flexibility in carriers of this genetic variant. The discussion relates the present finding to those of previous studies assessing the neurogenetic foundations of inhibitory control.
行为调整以适应不断变化的目标和环境约束需要在不同任务集之间灵活切换。认知灵活性是执行功能的一种内表型，双胞胎研究表明其具有高度遗传性。最近，通过任务转换范式中的反应时测量评估的整体灵活性的个体差异与多巴胺 D2 受体基因 DRD2 附近的单核苷酸多态性有关。在本研究中，我们评估了 DRD2 基因是否与反向抑制有关，反向抑制是一种通过不再相关的任务集减少前摄干扰来促进认知灵活性的控制机制。我们发现，与 A1-携带者相比，携带 DRD2 A1+变体的个体纹状体多巴胺 D2 受体密度较低，其反向抑制效应较大。这与先前的结果一致，表明该遗传变体的携带者具有更高的行为灵活性。讨论将目前的发现与先前评估抑制控制神经遗传基础的研究结果联系起来。
