Carpenter Erin, Peñaloza Claudia, Rao Leela, Kiran Swathi
Aphasia Research Laboratory, Department of Speech, Language and Hearing Sciences, Sargent College of Health & Rehabilitation Sciences, Boston University, Boston, MA, USA.
Neurobiol Lang (Camb). 2021 Dec 23;2(4):532-557. doi: 10.1162/nol_a_00053. eCollection 2021.
Different linguistic contexts place varying amounts of cognitive control on lexical retrieval in bilingual speakers, an issue that is complicated in bilingual patients with aphasia (BPWA) due to subsequent language and cognitive deficits. Verbal fluency tasks may offer insight into the interaction between executive and language control in healthy bilinguals and BPWA, by examining conditions with varying cognitive control demands. The present study examined switching and clustering in verbal fluency tasks in BPWA and healthy bilinguals across single- and dual-language conditions. We also examined the influence of language processing and language proficiency on switching and clustering performance across the dual-language conditions. Thirty-five Spanish-English BPWA and twenty-two Spanish-English healthy bilinguals completed a language use questionnaire, tests of language processing, and two verbal fluency tasks. The semantic category generation task included four conditions: two single-language conditions (No-Switch L1 and No-Switch L2) that required word production in each language separately; one dual-language condition that allowed switching between languages as desired (Self-Switch); and one dual-language condition that required switching between languages after each response (Forced-Switch). The letter fluency task required word production in single-language contexts. Overall, healthy bilinguals outperformed BPWA across all measures. Results indicate that switching is more sensitive to increased control demands than clustering, with this effect being more pronounced in BPWA, underscoring the interaction between semantic executive processes and language control in this group. Additionally, for BPWA switching performance relies on a combination of language abilities and language experience metrics.
不同的语言环境对双语者的词汇检索施加了不同程度的认知控制，对于患有失语症的双语患者（BPWA）来说，由于随后出现的语言和认知缺陷，这个问题变得更加复杂。言语流畅性任务可以通过检查具有不同认知控制要求的条件，来深入了解健康双语者和BPWA中执行控制与语言控制之间的相互作用。本研究考察了BPWA和健康双语者在单语言和双语条件下的言语流畅性任务中的转换和聚类情况。我们还考察了在双语条件下语言处理和语言熟练度对转换和聚类表现的影响。35名西班牙语-英语双语失语症患者和22名西班牙语-英语健康双语者完成了一份语言使用问卷、语言处理测试以及两项言语流畅性任务。语义类别生成任务包括四种条件：两种单语言条件（非转换L1和非转换L2），分别要求用每种语言单独生成单词；一种双语条件，允许根据需要在两种语言之间切换（自我转换）；以及一种双语条件，要求在每次回答后在两种语言之间切换（强制转换）。字母流畅性任务要求在单语言环境中生成单词。总体而言，在所有测量指标上，健康双语者的表现均优于BPWA。结果表明，转换比聚类对增加的控制要求更敏感，这种效应在BPWA中更为明显，突出了该群体中语义执行过程与语言控制之间的相互作用。此外，对于BPWA来说，转换表现依赖于语言能力和语言经验指标的综合作用。
