Supplementary Material for: Visual Attention and Saccadic Oculomotor Control in Parkinson's Disease

<b><i>Background:</i></b> In patients with Parkinson's disease (PD) we aimed at differentiating the relation between selective visual attention, deficits of programming and dynamics of saccadic eye movements while searching for a target and hand-reaction time as well as hand-movement time. Visual attention is crucial for concentrating selectively on one aspect of the visual field while ignoring other aspects. Eye movements are anatomically and functionally related to mechanisms of visual attention. Saccadic dysfunction might confound selective visual attention in PD. <b><i>Methods:</i></b> We studied visual selective attention in 22 medicated PD patients (clinical ON status, mild to moderate disease severity) and 22 age matched controls. We looked for possible interferences through oculomotor deficits. Two tasks were compared: free viewing of photographs and time optimal visual search of a hidden target. Visual search times (VST), task related dynamics of saccades, and hand-reaction and hand-movement times were analyzed. <b><i>Results:</i></b> In the free viewing task mild to moderately affected PD patients did not differ statistically from healthy subjects with respect to saccade dynamics. However, patients differed significantly from healthy subjects in the time optimal visual search task with 25% lower rates of successful searches. Hand movement reaction time did not differ in both groups, whereas hand movement execution time was significantly prolonged in PD patients. <b><i>Conclusion:</i></b> Saccadic oculomotor control and hand movement reaction times were intact, whereas in our less severely affected treated PD patients, visual selective attention was not. The highly reduced successful search rate might be related to disturbed programming and delayed execution of saccades during time optimal visual search due to decreased execution of serial-order sequential generation of saccades.

**背景：** 本研究针对帕金森病（PD）患者，旨在厘清选择性视觉注意、目标搜索时扫视眼动的编程与动力学特征缺损，与手部反应时、手部运动时之间的关联差异。视觉注意的核心作用在于，可选择性地聚焦于视觉场景的某一区域，同时忽略其余无关信息。眼动在解剖结构与功能层面均与视觉注意机制密切相关。帕金森病患者的扫视功能异常，可能会干扰其选择性视觉注意能力。
**方法：** 本研究纳入22例接受药物治疗的帕金森病患者（处于临床“开期”，病情为轻至中度），以及22例年龄匹配的健康对照者，对其视觉选择性注意能力进行评估，并探究动眼功能缺损可能带来的干扰效应。本研究设置两项任务进行对照：自由观看图片任务，以及隐藏目标的时间最优视觉搜索任务。研究对视觉搜索时（VST）、任务相关的扫视动力学特征，以及手部反应时与手部运动时进行了分析。
**结果：** 在自由观看任务中，轻中度帕金森病患者与健康对照者的扫视动力学特征无统计学差异。但在时间最优视觉搜索任务中，患者与健康对照者存在显著差异：患者的成功搜索率较对照降低25%。两组受试者的手部反应时无显著差异，但帕金森病患者的手部运动执行时显著延长。
**结论：** 本研究中接受药物治疗的轻度帕金森病患者，其扫视动眼控制能力与手部反应时均保持完好，但选择性视觉注意功能存在缺损。时间最优视觉搜索任务中成功搜索率的大幅降低，或与串行顺序扫视生成能力受损相关，进而导致该任务中扫视编程紊乱、执行延迟。