Abstract

The bilingual experience is believed to impact brain development and, possibly, cognitive performance. Subcortical structures, including the striatum and white matter, are believed related to confrontation naming performance among bilingual individuals with later age of acquisition (AoA) and lower proficiency of a second language (L2). However, these findings are primarily derived from healthy adult samples, although there is clinical significance for the interpretation of naming performance. The present study examined whether striatal and white matter lesions were associated with naming tasks in clinic-referred bilingual veterans (n = 29) and whether L2 AoA moderated this relationship. Clinically rated lesions, without regard for AoA, were not consistently correlated with naming performance. Moderation models (lesion × AoA) were significant across naming tasks (i.e., naming scores were negatively correlated with striatal lesions with increasing AoA). Effect sizes were higher among striatal models as compared to white matter models. Results extend prior neuroimaging findings with healthy bilinguals that AoA moderates the relationship between subcortical lesions and naming performance in bilingual patients, and suggests that clinicians should consider specifics of bilingual experience when interpreting test scores.

摘要

双语体验被认为会影响大脑发育，并可能影响认知表现。皮层下结构，包括纹状体和白质，被认为与晚习得年龄 (AoA) 和较低第二语言 (L2) 熟练程度的双语个体的对抗命名表现有关。然而，这些发现主要来自健康成人样本，尽管对命名表现的解释具有临床意义。本研究检查了纹状体和白质病变是否与诊所转诊的双语退伍军人的命名任务相关（n = 29) 以及 L2 AoA 是否调节了这种关系。在不考虑 AoA 的情况下，临床评定的病变与命名表现并不一致。调节模型（病变×AoA）在命名任务中很重要（即，随着AoA 的增加，命名分数与纹状体病变呈负相关）。与白质模型相比，纹状体模型的效应量更高。结果扩展了先前对健康双语者的神经影像学发现，即 AoA 调节双语患者皮质下病变与命名能力之间的关系，并建议临床医生在解释测试分数时应考虑双语体验的细节。