Visuomotor Control Laboratory, Human Systems Integration Division, NASA Ames Research Center, Moffett Field, CA, USA.
San José State University, San José, CA, USA.
J Physiol. 2019 Sep;597(17):4643-4660. doi: 10.1113/JP277779. Epub 2019 Aug 6.
Inadequate sleep and irregular work schedules have not only adverse consequences for individual health and well-being, but also enormous economic and safety implications for society as a whole. This study demonstrates that visual motion processing and coordinated eye movements are significantly impaired when performed after sleep loss and during the biological night, and thus may be contributing to human error and accidents. Because affected individuals are often unaware of their sensorimotor and cognitive deficits, there is a critical need for non-invasive, objective indicators of mild, yet potentially unsafe, impairment due to disrupted sleep or biological rhythms. Our findings show that a set of eye-movement measures can be used to provide sensitive and reliable indicators of such mild neural impairments.
Sleep loss and circadian misalignment have long been known to impair human cognitive and motor performance with significant societal and health consequences. It is well known that human reaction time to a visual cue is impaired following sleep loss and circadian misalignment, but it has remained unclear how more complex visuomotor control behaviour is altered under these conditions. In this study, we measured 14 parameters of the voluntary ocular tracking response of 12 human participants (six females) to systematically examine the effects of sleep loss and circadian misalignment using a constant routine 24-h acute sleep-deprivation paradigm. The combination of state-of-the-art oculometric and sleep-research methodologies allowed us to document, for the first time, large changes in many components of pursuit, saccades and visual motion processing as a function of time awake and circadian phase. Further, we observed a pattern of impairment across our set of oculometric measures that is qualitatively different from that observed previously with other mild neural impairments. We conclude that dynamic vision and visuomotor control exhibit a distinct pattern of impairment linked with time awake and circadian phase. Therefore, a sufficiently broad set of oculometric measures could provide a sensitive and specific behavioural biomarker of acute sleep loss and circadian misalignment. We foresee potential applications of such oculometric biomarkers assisting in the assessment of readiness-to-perform higher risk tasks and in the characterization of sub-clinical neural impairment in the face of a multiplicity of potential risk factors, including disrupted sleep and circadian rhythms.
睡眠不足和不规律的工作时间安排不仅对个人的健康和幸福产生不利影响，而且对整个社会的经济和安全也产生巨大影响。本研究表明，在睡眠不足和生物夜间进行时，视觉运动处理和协调的眼球运动明显受损，因此可能导致人为错误和事故。由于受影响的个体通常没有意识到自己的感觉运动和认知缺陷，因此迫切需要非侵入性的客观指标来检测因睡眠或生物节律紊乱而导致的轻度但潜在不安全的损伤。我们的研究结果表明，一组眼球运动测量指标可用于提供敏感而可靠的轻度神经损伤指标。
睡眠不足和昼夜节律失调早已被证实会损害人类的认知和运动表现，对社会和健康造成重大影响。众所周知，人类对视觉提示的反应时间在睡眠不足和昼夜节律失调后会受到损害，但在这些情况下，更复杂的视觉运动控制行为如何改变仍不清楚。在这项研究中，我们测量了 12 名参与者（6 名女性）的自愿眼球追踪反应的 14 个参数，使用恒常例行 24 小时急性睡眠剥夺范式系统地检查了睡眠不足和昼夜节律失调的影响。最先进的眼动测量和睡眠研究方法的结合使我们首次记录了在清醒时间和昼夜相位的影响下，追踪、扫视和视觉运动处理的许多成分的大变化。此外，我们观察到一组眼动测量指标中的损伤模式与以前用其他轻度神经损伤观察到的模式不同。我们得出结论，动态视觉和视觉运动控制表现出与清醒时间和昼夜相位相关的明显损伤模式。因此，足够广泛的眼动测量指标可以提供敏感和特异性的急性睡眠不足和昼夜节律失调的行为生物标志物。我们预计，这种眼动生物标志物的潜在应用可以帮助评估执行高风险任务的准备情况，并在面对多种潜在风险因素（包括睡眠和昼夜节律紊乱）时，描述亚临床神经损伤。
