Kemp Amy, Eddins David, Shrivastav Rahul, Hampton Wray Amanda
Department of Communicative Sciences & Disorders, Michigan State University, East Lansing.
Department of Communication Sciences & Disorders, University of South Florida, Tampa.
J Speech Lang Hear Res. 2019 Feb 26;62(2):367-386. doi: 10.1044/2018_JSLHR-H-17-0396.
Purpose Improving the ability to listen efficiently in noisy environments is a critical goal for hearing rehabilitation. However, understanding of the impact of difficult listening conditions on language processing is limited. The current study evaluated the neural processes underlying semantics in challenging listening conditions. Method Thirty adults with normal hearing completed an auditory sentence processing task in 4-talker babble. Event-related brain potentials were elicited by the final word in high- or low-context sentences, where the final word was either highly expected or not expected, followed by a 4-alternative forced-choice response with either longer (1,000 ms), middle (700 ms), or shorter (400 ms) response time deadlines (RTDs). Results Behavioral accuracy was reduced, and reactions times were faster for shorter RTDs. N400 amplitudes, reflecting ease of lexical access, were larger when elicited by target words in low-context sentences followed by shorter compared with longer RTDs. Conclusions These results reveal that more neural resources are allocated for semantic processing/lexical access when listening difficulty increases. Differences between RTDs may reflect increased attentional allocation for shorter RTDs. These findings suggest that situational listening demands can impact the demands for cognitive resources engaged in language processing, which could significantly impact listener experiences across environments.
目的 提高在嘈杂环境中有效倾听的能力是听力康复的一个关键目标。然而，对于困难倾听条件对语言处理的影响的理解是有限的。当前的研究评估了在具有挑战性的倾听条件下语义理解的神经过程。方法 30名听力正常的成年人在四说话者嘈杂声环境中完成了一项听觉句子处理任务。高语境或低语境句子的最后一个单词诱发事件相关脑电位，其中最后一个单词要么是高度可预期的，要么是不可预期的，随后是一个4选1的强制选择反应，反应时间截止（RTD）分别为较长（1000毫秒）、中等（700毫秒）或较短（400毫秒）。结果 行为准确性降低，较短的RTD反应时间更快。反映词汇通达难易程度的N400波幅，在低语境句子中的目标单词诱发时，与较长的RTD相比，较短的RTD诱发时更大。结论 这些结果表明，当倾听难度增加时，会分配更多的神经资源用于语义处理/词汇通达。RTD之间的差异可能反映了较短RTD时注意力分配的增加。这些发现表明，情境性倾听需求会影响语言处理中认知资源的需求，这可能会显著影响不同环境下的倾听体验。
