Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboudumc, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University, P.O. Box 9010//066, 6500 GL, Nijmegen, The Netherlands.
Sci Rep. 2022 Mar 28;12(1):5262. doi: 10.1038/s41598-022-09029-8.
Several studies have proposed that an optimal speed-accuracy tradeoff underlies the stereotyped relationship between amplitude, duration and peak velocity of saccades (main sequence). To test this theory, we asked 8 participants to make saccades to Gaussian-blurred spots and manipulated the task's accuracy constraints by varying target size (1, 3, and 5°). The largest targets indeed yielded more endpoint scatter (and lower gains) than the smallest targets, although this effect subsided with target eccentricity. The main sequence depended on several interacting factors: saccade latency, saccade gain and target size. Early saccades, which were faster than amplitude-matched late saccades, followed the target-size dependency one would expect from a speed-accuracy tradeoff process. They had higher peak velocities and shorter durations for larger targets than for smaller targets. For late saccades, however, the opposite was found. Deviations from the main sequence also covaried with saccade gain, in line with the idea that motor noise underlies part of the endpoint variability. Thus, our data provide partial evidence that the saccadic system weighs the detrimental effects of motor noise on saccade accuracy against movement duration and speed, but other factors also modulate the kinematics. We discuss the possible involvement of parallel saccade pathways to account for our findings.
已有几项研究提出，在眼跳的幅度、持续时间和峰值速度之间的这种刻板关系（主序列）的背后存在一个最佳速度-准确性权衡。为了检验这一理论，我们要求 8 名参与者向高斯模糊点进行眼跳，并通过改变目标大小（1、3 和 5°）来改变任务的准确性约束。最大的目标确实比最小的目标产生了更大的终点散布（和更低的增益），尽管这种效应随着目标的偏心度而减弱。主序列取决于几个相互作用的因素：眼跳潜伏期、眼跳增益和目标大小。比幅度匹配的晚期眼跳更快的早期眼跳遵循了人们预期的从速度-准确性权衡过程中得出的目标大小依赖性。它们的峰值速度更高，持续时间更短，目标越大，持续时间越短。然而，对于晚期眼跳，情况正好相反。偏离主序列也与眼跳增益相关，这与运动噪声是终点变异性部分原因的观点一致。因此，我们的数据提供了部分证据表明，眼跳系统权衡了运动噪声对眼跳准确性的不利影响，以换取运动持续时间和速度，但其他因素也调节了运动学。我们讨论了平行眼跳通路的可能参与，以解释我们的发现。
