Unfolding of cognitive effort in aphasia (Chapman & Hallowell, 2021)

Purpose: Arousal and cognitive effort are relevant yet often overlooked components of attention during language processing. Pupillometry can be used to provide a psychophysiological index of arousal and cognitive effort. Given that much is unknown regarding the relationship between cognition and language deficits seen in people with aphasia (PWA), pupillometry may be uniquely suited to explore those relationships. The purpose of this study was to examine arousal and the time course of the allocation of cognitive effort related to sentence processing in people with and without aphasia.Method: Nineteen PWA and age- and education-matched control participants listened to relatively easy (subject-relative) and relatively difficult (object-relative) sentences and were required to answer occasional comprehension questions. Tonic and phasic pupillary responses were used to index arousal and the unfolding of cognitive effort, respectively, while sentences were processed. Group differences in tonic and phasic responses were examined.Results: Group differences were observed for both tonic and phasic responses. PWA exhibited greater overall arousal throughout the task compared with controls, as evidenced by larger tonic pupil responses. Controls exhibited more effort (greater phasic responses) for difficult compared with easy sentences; PWA did not. Group differences in phasic responses were apparent during end-of-sentence and postsentence time windows.Conclusions: Results indicate that the attentional state of PWA in this study was not consistently supportive of adequate task engagement. PWA in our sample may have relatively limited attentional capacity or may have challenges with allocating existing capacity in ways that support adequate task engagement and performance. This work adds to the body of evidence supporting the validity of pupillometric tasks for the study of aphasia and contributes to a better understanding of the nature of language deficits in aphasia.Supplemental Material S1. PWA detailed neuroimaging information. Chapman, L. R., & Hallowell, B. (2021). The unfolding of cognitive effort during sentence processing: Pupillometric evidence from people with and without aphasia. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2021_JSLHR-21-00129

目的：唤起与认知努力是语言处理过程中相关但常被忽视的注意力组成部分。瞳孔测量的应用能够提供唤起与认知努力的生理心理指标。鉴于关于非流利性语言障碍（PWA）患者认知与语言障碍之间关系的研究尚不充分，瞳孔测量可能特别适用于探索这些关系。本研究旨在探讨患有和非患有非流利性语言障碍的人群在句子处理过程中唤起与认知努力的时间分配。方法：十九名非流利性语言障碍患者与年龄和教育程度相匹配的对照组参与者聆听了相对简单（主语相对）和相对困难（宾语相对）的句子，并被要求偶尔回答理解问题。在句子处理过程中，通过分析节律性瞳孔反应和相位性瞳孔反应来分别衡量唤起与认知努力的展开。对节律性和相位性反应的组间差异进行了考察。结果：在节律性和相位性反应方面均观察到组间差异。与非流利性语言障碍患者相比，对照组在整个任务期间表现出更高的整体唤起，这由更大的节律性瞳孔反应所证实。与对照组相比，对照组在处理困难句子时表现出更多的努力（更大的相位性反应），而非流利性语言障碍患者则不然。在句末和句后时间窗口中，相位性反应的组间差异显著。结论：结果表明，本研究中非流利性语言障碍患者的注意力状态并不始终支持足够的任务参与。在我们的样本中，非流利性语言障碍患者可能具有相对有限的眼动注意力容量，或者可能在分配现有容量以支持足够的任务参与和表现方面存在挑战。本研究为支持瞳孔测量任务在非流利性语言障碍研究中的有效性提供了更多证据，并有助于更好地理解非流利性语言障碍的语言障碍本质。补充材料S1：非流利性语言障碍患者的详细神经影像信息。Chapman, L. R. & Hallowell, B. (2021). 句子处理过程中认知努力的展开：来自患有和非患有非流利性语言障碍人群的瞳孔测量证据。言语、语言和听力研究杂志。在线预发表。https://doi.org/10.1044/2021_JSLHR-21-00129