Goettker Alexander
Justus Liebig University, Giessen, Germany.
J Vis. 2021 May 3;21(5):28. doi: 10.1167/jov.21.5.28.
The oculomotor system makes use of an integration of previous stimulus velocities (the prior) and current sensory inputs to adjust initial eye speeds. The present study extended this research by investigating the roles of different retinal or extra-retinal signals for this process. To test for this, participants viewed movement sequences that all ended with the same test trial. Earlier in the sequence, the prior was manipulated by presenting targets that either had different velocities, different starting positions, or target movements designed to elicit differential oculomotor behavior (tracked with or without additional corrective saccades). Additionally, these prior targets could vary in terms of contrast to manipulate reliability. When the velocity of prior trials differed from test trials, the reliability-weighted integration of prior information was replicated. When the prior trials differed in starting position, significant effects on subsequent oculomotor behavior were only observed for the reliable target. Although there were also differences in eye velocity across the different manipulations, they could not explain the observed reliability-weighted integration. When comparing the same physical prior trials but tracked with additional corrective saccades, the eye velocity in the test trial also differed systematically (slower for forward saccades, and faster for backward saccades). The direction of the observed effect contradicts the expectations based on perceived speed and eye velocity, but can be predicted by a combination of retinal velocity and position error signals. Together, these results suggest that general fluctuations in eye velocity as well as retinal error signals are related to oculomotor behavior in subsequent trials.
动眼系统利用先前刺激速度(先验信息)和当前感觉输入的整合来调整初始眼速。本研究通过调查不同视网膜或视网膜外信号在此过程中的作用扩展了这项研究。为了对此进行测试,参与者观看了所有以相同测试试验结束的运动序列。在序列的早期,通过呈现具有不同速度、不同起始位置或旨在引发不同动眼行为(有或没有额外校正扫视跟踪)的目标来操纵先验信息。此外,这些先前目标在对比度方面可能有所不同,以操纵可靠性。当先验试验的速度与测试试验不同时,先验信息的可靠性加权整合得以重现。当先验试验在起始位置不同时,仅在可靠目标上观察到对后续动眼行为的显著影响。尽管在不同操纵之间眼速也存在差异,但它们无法解释观察到的可靠性加权整合。当比较相同的物理先验试验但用额外的校正扫视跟踪时,测试试验中的眼速也系统地不同(向前扫视时较慢,向后扫视时较快)。观察到的效应方向与基于感知速度和眼速的预期相矛盾,但可以通过视网膜速度和位置误差信号的组合来预测。总之,这些结果表明眼速的一般波动以及视网膜误差信号与后续试验中的动眼行为有关。