Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA.
Neuroimage. 2010 Nov 1;53(2):653-63. doi: 10.1016/j.neuroimage.2010.06.062. Epub 2010 Jun 30.
Understanding which brain regions regulate the execution, and suppression, of goal-directed behavior has implications for a number of areas of research. In particular, understanding which brain regions engaged during tasks requiring the execution and inhibition of a motor response provides insight into the mechanisms underlying individual differences in response inhibition ability. However, neuroimaging studies examining the relation between activation and stopping have been inconsistent regarding the direction of the relationship, and also regarding the anatomical location of regions that correlate with behavior. These limitations likely arise from the relatively low power of voxelwise correlations with small sample sizes. Here, we pooled data over five separate fMRI studies of the Stop-signal task in order to obtain a sufficiently large sample size to robustly detect brain/behavior correlations. In addition, rather than performing mass univariate correlation analysis across all voxels, we increased statistical power by reducing the dimensionality of the data set using independent component analysis and then examined correlations between behavior and the resulting component scores. We found that components reflecting activity in regions thought to be involved in stopping were associated with better stopping ability, while activity in a default-mode network was associated with poorer stopping ability across individuals. These results clearly show a relationship between individual differences in stopping ability in specific activated networks, including regions known to be critical for the behavior. The results also highlight the usefulness of using dimensionality reduction to increase the power to detect brain/behavior correlations in individual differences research.
理解哪些大脑区域调节目标导向行为的执行和抑制，对许多研究领域都有意义。特别是，了解在需要执行和抑制运动反应的任务中哪些大脑区域被激活，可以深入了解个体反应抑制能力差异的机制。然而，检查激活与停止之间关系的神经影像学研究在关系的方向上以及与行为相关的区域的解剖位置上一直存在不一致。这些局限性可能源于与小样本量相关的体素相关的相对较低的功率。在这里，我们汇集了五个单独的停止信号任务 fMRI 研究的数据，以便获得足够大的样本量来稳健地检测大脑/行为相关性。此外，我们不是对所有体素进行大规模的单变量相关分析，而是通过使用独立成分分析来降低数据集的维度，从而增加统计功效，然后检查行为与得到的成分得分之间的相关性。我们发现，反映被认为与停止有关的区域活动的成分与更好的停止能力相关，而个体之间默认模式网络的活动与较差的停止能力相关。这些结果清楚地表明，在特定的激活网络中，个体停止能力的差异与大脑/行为相关性之间存在关系，包括对行为至关重要的区域。这些结果还突出了使用降维来提高个体差异研究中检测大脑/行为相关性的功率的有用性。
