Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, New Taipei City 235, Taiwan.
Int J Environ Res Public Health. 2022 Jul 28;19(15):9234. doi: 10.3390/ijerph19159234.
Saccadic eye movements are directed to the objects of interests and enable high-resolution visual images in the exploration of the visual world. There is a trial-to-trial variation in saccade dynamics even in a simple task, possibly attributed to arousal fluctuations. Previous studies have showed that an increase of fatigue level over time, also known as time-on-task, can be revealed by saccade peak velocity. In addition, pupil size, controlled by the autonomic nervous system, has long been used as an arousal index. However, limited research has been done with regards to the relation between pupil size and saccade behavior in the context of trial-to-trial variation. To investigate fatigue and arousal effects on saccadic and pupillary responses, we used bright and emotional stimuli to evoke pupillary responses in tasks requiring reactive and voluntary saccade generation. Decreased voluntary saccade peak velocities, reduced tonic pupil size and phasic pupillary responses were observed as time-on-task increased. Moreover, tonic pupil size affected saccade latency and dynamics, with steeper saccade main sequence slope as tonic pupil size increased. In summary, saccade dynamics and tonic pupil size were sensitive to fatigue and arousal level, together providing valuable information for the understanding of human behavior.
扫视眼动被引导至感兴趣的物体，使我们能够在探索视觉世界时获得高分辨率的视觉图像。即使在简单的任务中，扫视的动力学也存在个体间的差异，这可能归因于觉醒波动。先前的研究表明，随着时间的推移，疲劳水平的增加，即任务时间，可通过扫视的峰值速度揭示出来。此外，由自主神经系统控制的瞳孔大小长期以来一直被用作觉醒指标。然而，在个体间差异的背景下，关于瞳孔大小和扫视行为之间的关系的研究还很有限。为了研究疲劳和觉醒对扫视和瞳孔反应的影响，我们使用明亮和情绪化的刺激来诱发需要反应性和自愿性扫视产生的瞳孔反应。随着任务时间的增加，我们观察到自愿性扫视峰值速度降低、紧张性瞳孔大小减小和相位性瞳孔反应减少。此外，紧张性瞳孔大小影响扫视潜伏期和动力学，随着紧张性瞳孔大小的增加，扫视主序列斜率变陡。总之，扫视动力学和紧张性瞳孔大小对疲劳和觉醒水平敏感，共同为理解人类行为提供了有价值的信息。
