Research has shown that older adults have increased difficulty comprehending foreign-accented speech. As these studies have only used behavioral measures, we exploited the fine-grained temporal resolution of EEG/ERPs to examine neural signatures of foreign- and native-accented sentence comprehension in older adults. Older adults, all normal-hearing monolingual English speakers, listened to foreign Chinese-accented and native English-accented sentences while ERPs were recorded. Foreign- and native-accented sentences contained semantic or pronoun errors, or were semantically and grammatically correct. We also gathered behavioral measures of sentence comprehension, and examined how neural activity during sentence processing relates to individual differences in listeners’ attitudes towards accented speakers, linguistic and cognitive skills, and hearing acuity. Older adults showed high comprehension accuracy of both foreign-accented and native-accented sentences. In contrast, ERP data showed different neural responses to foreign- and native-accented sentences: Semantic errors elicited an N400 effect in native-accented sentences, but not in foreign-accented sentences. Grammatical errors elicited a P600, not further qualified by accent type. Hearing acuity and individual differences in language attitudes, cognitive and linguistic variables did not systematically correlate with ERP patterns. These findings suggest that older adults are ultimately engaging in foreign-accented sentence comprehension, but non-native pre-lexical speech signals do not attain activation needed for strong lexical activation during online processing, resulting in strained and more effortful higher-level processing of semantics downstream the sentence.

研究表明，老年人理解外国口音的难度增加。由于这些研究仅使用行为测量，我们利用 EEG/ERP 的细粒度时间分辨率来检查老年人外国口音和本地口音句子理解的神经特征。老年人，所有听力正常的单语英语人士，在记录 ERP 的同时听外国汉语口音和母语英语口音的句子。外国口音和母语口音的句子包含语义或代词错误，或者在语义和语法上是正确的。我们还收集了句子理解的行为测量，并检查了句子处理过程中的神经活动如何与听众对口音说话者的态度、语言和认知技能的个体差异相关联，和听力。老年人对外国口音和本国口音的句子都表现出很高的理解准确性。相比之下，ERP 数据显示对外国口音和本国口音句子的不同神经反应：语义错误在本国口音句子中引起 N400 效应，但在外国口音句子中没有。语法错误导致 P600，未进一步按重音类型限定。听力敏锐度和语言态度、认知和语言变量的个体差异与 ERP 模式没有系统地相关。这些发现表明，老年人最终会参与外语句子理解，但非母语前词汇语音信号在在线处理过程中无法获得强烈词汇激活所需的激活，