A comparison of pursuit eye movement and perceptual performance in speed discrimination
A comparison of pursuit eye movement and perceptual performance in speed discrimination
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DOI：
10.1167/3.11.19
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发表时间：
2003-01-01
影响因子：
1.8
通讯作者：
Hawken, MJ
中科院分区：
文献类型：
--
作者：
Gegenfurtner, KR;Xing, DJ;Hawken, MJ
目前，对于负责感知和运动表现的通路的性质存在相当多的争论。我们研究了感知速度（移动刺激的体验表征）与平滑追踪眼球运动（运动动作）的速度之间的关系。我们确定了用于检测移动模式速度中的小扰动的心理物理学阈值，然后通过理想观察者分析，从相同试验中相同刺激引起的眼球运动轨迹中计算出类似的“眼测量”阈值。我们的结果证实了之前的研究结果，即速度辨别的感知判断与眼球运动速度的精细分级之间存在显着的一致性。我们分析了长持续时间（1000 ms）和短持续时间（200 ms）扰动的初始追踪期。当我们在反复试验的基础上比较感知和追踪的误差时，发现感知误差和眼动误差之间没有相关性。观察到眼测量和心理测量的表现相似，韦伯分数在正常范围内，但误差不存在相关性，这表明运动系统和感知在运动信号分析中具有相同的约束，但独立行动并具有不同的噪声源。我们在两个感知和眼动性能模型中模拟了噪声。在第一个模型中，我们假设感知和眼动信号的初始公共源。在这种情况下，需要观察到的噪声的大约十倍才能在逐次试验的性能中产生不相关性。在第二个模型中，我们假设感知信号是再传入眼速度信号加上扰动信号的组合，而追踪信号则来自动眼植物加上扰动信号。在此模型中，独立信号中大约三倍的噪声水平将掩盖由于共同扰动信号而产生的任何相关性。
Currently there is considerable debate as to the nature of the pathways that are responsible for the perception and motor performance. We have studied the relationship between perceived speed, which is the experiential representation of a moving stimulus, and the speed of smooth pursuit eye movements, the motor action. We determined psychophysical thresholds for detecting small perturbations in the speed of moving patterns, and then by an ideal observer analysis computed analogous "oculometric" thresholds from the eye movement traces elicited by the same stimuli on the same trials. Our results confirm those of previous studies that show a remarkable agreement between perceptual judgments for speed discrimination and the fine gradations in eye movement speed. We analyzed the initial pursuit period of long duration (1000 ms) and short (200 ms) duration perturbations. When we compared the errors for perception and pursuit on a trial-by-trial basis there was no correlation between perceptual errors and eye movement errors. The observation that both oculometric and psychometric performance were similar, with Weber fractions in the normal range, but that there is no correlation in the errors suggests that the motor system and perception share the same constraints in their analysis of motion signals, but act independently and have different noise sources. We simulated noise in two models of perceptual and eye movement performance. In the first model we postulate an initial common source for the perceptual and eye movement signals. In that case about ten times the observed noise is required to produce no correlation in trial-by-trial performance. In the second model we postulate that the perceptual signal is a combination of a reafferent eye velocity signal plus the perturbation signal while the pursuit signal is derived from the oculomotor plant plus the perturbation signal. In this model about three times the noise level in the independent signals will mask any correlation due to the common perturbation signal.