Studies suggest that bilingualism may be associated with better cognition, but the role of active bilingualism, the daily use of two languages, on cognitive trajectories remains unclear. One hypothesis is that frequent language switching may protect cognitive trajectories against effects of brain atrophy. Here, we examined interaction effects between language and brain variables on cognition among Hispanic participants at baseline (N = 153) and longitudinally (N = 84). Linguistic measures included self-reported active Spanish–English bilingualism or Spanish monolingualism. Brain measures included, at baseline, regions of gray matter (GM) thickness strongly correlated with cross-sectional episodic memory and executive function and longitudinally, tissue atrophy rates correlated with episodic memory and executive function change. Active Spanish–English bilinguals showed reduced association strength between cognition and gray matter thickness cross-sectionally, β=0.303, p < .01 but not longitudinally, β=0.024, p = 0.105. Thus, active bilingualism may support episodic memory and executive function despite GM atrophy cross-sectionally, but not longitudinally.

中文翻译：

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双语会减少基线时认知与大脑之间的关联，但随着时间的推移并没有显示出认知储备的证据

研究表明，双语可能与更好的认知有关，但主动双语（即日常使用两种语言）对认知轨迹的作用仍不清楚。一种假设是，频繁的语言转换可以保护认知轨迹免受脑萎缩的影响。在这里，我们研究了语言和大脑变量之间的相互作用对西班牙裔参与者的认知的影响，包括基线（N = 153）和纵向（N = 84）。语言测量包括自我报告的活跃的西班牙语-英语双语或西班牙语单语。大脑测量包括，在基线时，灰质（GM）区域厚度与横截面情景记忆和执行功能密切相关，纵向上，组织萎缩率与情景记忆和执行功能变化相关。活跃的西班牙语-英语双语者表现出认知与灰质厚度之间的横截面关联强度降低，β=0.303，p < .01 但不是纵向，β=0.024，p = 0.105。因此，尽管 GM 出现横断面萎缩，但活跃的双语能力可能支持情景记忆和执行功能，但不能支持纵向萎缩。