Kaye Geoffrey, Johnston Edan, Burke Jaiden, Gasson Natalie, Marinovic Welber
School of Population Health (Psychology), Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia.
Psychophysiology. 2025 May;62(5):e70069. doi: 10.1111/psyp.70069.
Smooth pursuit eye movements (SPEM) are important to gather visual information that guides our interactions with moving objects (e.g., tracking a tennis ball, or following a car when driving). In many neurological conditions, from Parkinson's disease to stroke, the voluntary control of SPEM can be compromised. Therefore, SPEMs can serve as sensitive proxies for assessing cognitive and sensorimotor function. Prior research has shown that SPEMs are influenced by attention and working memory load, yet it remains unclear how the sensory modality of concurrent tasks interacts with these effects. Here, we conducted a 3 (working memory load: no load, easy [low load], and hard [high load]) × 2 (sensory modality: visual vs. auditory) experiment to examine how working memory load and secondary task modality interact to affect SPEM in healthy young adults. Participants tracked a moving circle while simultaneously performing an arithmetic task, where they added either constant (1) or variable (1-5) numbers which were presented visually or auditorily. Our results showed that a secondary auditory task increased tracking variability during high cognitive load. In contrast, we found that the visual task improved tracking, reducing variability irrespective of cognitive load. We interpret our results as evidence that auditory processing requires additional top-down control that is critical for the control of smooth pursuit, diverting resources required for smooth pursuit and, consequently, increasing SPEM variability. These findings emphasize the importance of sensory modality in understanding the interactions between working memory and oculomotor control. We suggest that auditory secondary cognitive tasks may provide a more sensitive test of sensorimotor control deficits in future research with clinical populations.
平稳跟踪眼球运动（SPEM）对于收集视觉信息很重要，这些信息指导我们与移动物体的互动（例如，跟踪网球，或开车时跟随汽车）。在许多神经系统疾病中，从帕金森病到中风，SPEM的自主控制可能会受到损害。因此，SPEM可作为评估认知和感觉运动功能的敏感指标。先前的研究表明，SPEM受注意力和工作记忆负荷的影响，但目前尚不清楚并发任务的感觉模态如何与这些影响相互作用。在这里，我们进行了一项3（工作记忆负荷：无负荷、轻松[低负荷]和困难[高负荷]）×2（感觉模态：视觉与听觉）实验，以研究工作记忆负荷和次要任务模态如何相互作用，从而影响健康年轻成年人的SPEM。参与者在跟踪一个移动的圆圈时，同时执行一项算术任务，他们要将视觉或听觉呈现的常数（1）或变量（1-5）相加。我们的结果表明，在高认知负荷下，次要听觉任务会增加跟踪的变异性。相比之下，我们发现视觉任务改善了跟踪，无论认知负荷如何，都能降低变异性。我们将我们的结果解释为证据，即听觉处理需要额外的自上而下的控制，这对于平稳跟踪的控制至关重要，会转移平稳跟踪所需的资源，从而增加SPEM的变异性。这些发现强调了感觉模态在理解工作记忆和眼动控制之间相互作用方面的重要性。我们建议，在未来对临床人群的研究中，听觉次要认知任务可能会提供一个更敏感的感觉运动控制缺陷测试。
