Rotman Research Institute, Baycrest Hospital, Toronto, Ontario, Canada.
Brain Cogn. 2010 Dec;74(3):347-57. doi: 10.1016/j.bandc.2010.09.004. Epub 2010 Oct 20.
To examine the effects of bilingualism on cognitive control, we studied monolingual and bilingual young adults performing a flanker task with functional MRI. The trial types of primary interest for this report were incongruent and no-go trials, representing interference suppression and response inhibition, respectively. Response times were similar between groups. Brain data were analyzed using partial least squares (PLS) to identify brain regions where activity covaried across conditions. Monolinguals and bilinguals activated different sets of brain regions for congruent and incongruent trials, but showed activation in the same regions for no-go trials. During the incongruent trials, monolinguals activated the left temporal pole and left superior parietal regions. In contrast, an extensive network including bilateral frontal, temporal and subcortical regions was active in bilinguals during the incongruent trials and in both groups for the no-go trials. Correlations between brain activity and reaction time difference relative to neutral trials revealed that monolinguals and bilinguals showed increased activation in different brain regions to achieve less interference from incongruent flankers. Results indicate that bilingualism selectively affects neural correlates for suppressing interference, but not response inhibition. Moreover, the neural correlates associated with more efficient suppression of interference were different in bilinguals than in monolinguals, suggesting a bilingual-specific network for cognitive control.
为了研究双语对认知控制的影响，我们使用功能磁共振成像技术研究了单语和双语的年轻成年人执行侧抑制任务的情况。本报告主要关注的试验类型是不一致和不可反应的试验，分别代表干扰抑制和反应抑制。两组的反应时间相似。使用偏最小二乘法（PLS）分析脑数据，以确定活动在条件之间共同变化的脑区。单语者和双语者在一致和不一致试验中激活了不同的脑区，但在不可反应试验中激活了相同的脑区。在不一致的试验中，单语者激活了左颞极和左顶叶上部区域。相比之下，在不一致的试验中，双语者的大脑活动涉及广泛的额、颞和皮质下区域，而在不可反应的试验中，两组的大脑活动都涉及这些区域。大脑活动与相对于中性试验的反应时间差异的相关性表明，单语者和双语者在不同的脑区表现出增加的激活，以减少来自不一致侧抑制器的干扰。结果表明，双语选择性地影响抑制干扰的神经相关性，但不影响反应抑制。此外，双语者与单语者相比，在更有效地抑制干扰方面的神经相关性不同，这表明双语者的认知控制存在特定的网络。
