裕固语-汉语习得者大脑灰质体积变化

Changes of brain grey matter volume in Yugur language-Chinese learners

目的 采用基于体素的形态学分析(VBM)观察裕固语-汉语习得者大脑灰质体积。方法 前瞻性对19名裕固族裕固语-汉语习得者(双语组)及20名汉族单一习得汉语者(单语组)采集头颅3D-T1WI并进行VBM全脑灰质体积分析,利用两样本t检验比较组间脑灰质体积的差异,分析其与蒙特利尔认知评估(MoCA)评分的相关性;以中介分析探讨双语组大脑灰质体积动态变化的可能机制。结果 双语组右侧顶下小叶、双侧颞中回、左侧背侧丘脑及右侧直回灰质体积均明显大于对照组(体素水平FWE校正,P均<0.05)。双语组右侧颞中回灰质体积与MoCA评分呈正相关(r=0.76,P<0.01),与左侧颞中回、右侧直回及左侧背侧丘脑体积均呈正相关(r=0.82、0.69、0.70,P均<0.05);左侧颞中回灰质体积与右侧直回体积呈正相关(r=0.61,P<0.05);中介分析结果显示,左侧背侧丘脑直接介导左侧颞中回灰质体积变化,右侧颞中回与右侧直回之间灰质体积变化受左侧颞中回介导,双侧颞中回灰质体积变化均受左侧背侧丘脑、右侧直回介导。结论 相比单一习得汉语者,裕固语-汉语习得者大脑灰质体积发生改变,且各脑区灰质体积均呈动态变化。

Objective To observe the changes of brain grey matter volumes in Yugur language-Chinese learners using voxel-based morphological(VBM)analysis,and to explore the possible dynamic mechanisms of these changes.Methods Brain 3D MR T1WI were prospectively acquired in 19 Yugur language-Chinese learners(double language group)and 20 single Chinese learners(single language group),then VBM whole-brain gray matter volume analysis was performed.The gray matter volumes were compared between groups using two-sample t test,and the correlations of the changes of grey matter volumes and Montreal cognitive assessment(MoCA)scores were analyzed.Mediated analysis was applied to explore the possible mechanisms of dynamic changes of grey matter volumes in bilingual group.Results The grey matter volume of the right inferior parietal lobule,bilateral middle temporal gyrus,left dorsal lateral thalamus and right gyrus rectus in bilingual group were larger than those in single language group(FWE corrected,all P<0.05).In bilingual group,grey matter volume of the right middle temporal gyrus was positively correlated with MoCA scores(r=0.76,P<0.01)and grey matter volume of left middle temporal gyrus,right gyrus rectus and left dorsal thalamus(r=0.82,0.69,0.70,all P<0.05),while gray matter volume of the left middle temporal gyrus was positively correlated with that of the right gyrus rectus(r=0.61,P<0.05).Mediation analysis showed that the left dorsal thalamus directly mediated the changes of gray matter volume in left middle temporal gyrus,while the changes of gray matter volume between the right middle temporal gyrus and the right gyrus rectus were mediated by the left middle temporal gyrus,of bilateral middle temporal gyrus was mediated by the left dorsal thalamus and the right gyrus rectus.Conclusion Compared with single Chines learners,the volumes of brain gray matter in Yugur language-Chinese learners were different,and dynamic changes of gray matter volumes were observed in relative brain areas.