Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
Behavioural and Cognitive Neuroscience Institute, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
Sci Rep. 2018 Sep 20;8(1):14112. doi: 10.1038/s41598-018-32504-0.
People must decide where, when, and for how long to allocate gaze to perform different motor behaviours. However, the factors guiding gaze during these ongoing, natural behaviours are poorly understood. Gaze shifts help acquire information, suggesting that people should direct gaze to locations where environmental details most relevant to the task are uncertain. To explore this, human subjects stepped on a series of targets as they walked. We used different levels of target uncertainty, and through instruction, altered the importance of (or subjective value assigned to) foot-placement accuracy. Gaze time on targets increased with greater target uncertainty when precise foot placement was more important, and these longer gaze times associated with reduced foot-placement error. Gaze times as well as the gaze shifts to and from targets relative to stepping differed depending on the target's position in the sequence and uncertainty level. Overall, we show that gaze is allocated to reduce uncertainty about target locations, and this depends on the value of this information gain for successful task performance. Furthermore, we show that the spatial-temporal pattern of gaze to resolve uncertainty changes with the evolution of the motor behaviour, indicating a flexible strategy to plan and control movement.
人们必须决定在何处、何时以及持续多长时间分配注视以执行不同的运动行为。然而，在这些正在进行的自然行为中，引导注视的因素理解得很差。注视转移有助于获取信息，这表明人们应该将目光投向环境细节对任务最不确定的地方。为了探索这一点，人类受试者在行走时踩到了一系列目标。我们使用了不同水平的目标不确定性，并通过指令改变了足部放置准确性的重要性（或主观赋值）。当精确的足部放置更重要时，目标不确定性越大，注视时间就越长，与足部放置错误的减少有关。注视时间以及相对于跨步的注视转移与从目标转移的时间取决于目标在序列中的位置和不确定性水平。总的来说，我们表明注视是为了减少对目标位置的不确定性，而这取决于信息获取对成功任务表现的价值。此外，我们还表明，解决不确定性的注视的时空模式会随着运动行为的演变而变化，这表明了一种灵活的策略来规划和控制运动。
