Faculty of Psychology and Educational Sciences, University of Geneva, Switzerland.
Department of Neurorehabilitation, Geneva University Hospitals, Switzerland.
J Speech Lang Hear Res. 2022 Oct 17;65(10):3758-3775. doi: 10.1044/2022_JSLHR-22-00096. Epub 2022 Oct 6.
While the involvement of attention in utterance planning is well established at the conceptual and lexical levels, the attentional demands of postlexical processes are still debated. This study investigates the involvement of attentional resources on motor speech encoding during utterance production in the context of Parkinson's disease (PD), a population allowing to assess if the attentional demands observed in a dual-task paradigm (the dual-task costs [DTCs]) are explained by postlexical difficulties and not solely by executive impairment.
Speech production was analyzed in a dual-task paradigm with 30 participants presenting with motor speech disorders due to hypokinetic dysarthria in the context of PD. The dual-task comprised an automatic speech task in which participants recited the days of the week and two nonverbal tasks evaluating processing speed and inhibition. The severity of dysarthria and performance in several executive tests (inhibition, verbal fluency, and cognitive shifting) were used as potential predictors of the DTCs.
Individuals with PD exhibited a DTC on the nonverbal tasks and on the speech task when the secondary task was inhibition (the most difficult one). Additionally, the severity of dysarthria and a poorer performance in cognitive shifting predicted a more severe DTC on speech rate. Finally, modulation of the magnitude of the DTCs was observed, depending on the difficulty of the nonverbal secondary task.
The results suggest that, in PD, postlexical processes require attentional resources and cognitive shifting is related to dual-task performance in speech.
虽然在概念和词汇层面上已经证实了注意力参与话语规划，但词汇后加工过程的注意力需求仍存在争议。本研究调查了在帕金森病（PD）的背景下，言语产生过程中词汇后加工阶段的注意力资源的参与情况，这一人群可用于评估在双重任务范式（双重任务成本[DTC]）中观察到的注意力需求是否是由词汇后加工困难引起的，而不仅仅是由执行功能障碍引起的。
在双重任务范式中分析言语产生，该范式涉及 30 名因运动性言语障碍而出现低动力性构音障碍的 PD 患者。双重任务包括一个自动言语任务，参与者在该任务中背诵星期的天数，以及两个非言语任务，评估处理速度和抑制能力。构音障碍的严重程度和几项执行功能测试（抑制、言语流畅性和认知转换）的表现被用作 DTC 的潜在预测指标。
PD 患者在非言语任务和抑制性的次要言语任务上表现出 DTC（最困难的任务）。此外，构音障碍的严重程度和认知转换能力较差与言语速度的 DTC 更严重相关。最后，取决于非言语次要任务的难度，观察到 DTC 的幅度有所调节。
研究结果表明，在 PD 中，词汇后加工过程需要注意力资源，认知转换与言语的双重任务表现有关。
