|其他题名||Mechanism of eye movements compensation in heading perception|
|关键词||自身运动认知 光流 眼动补偿 顶内沟 猕猴|
It is critical to correctly judge their self-motion direction for most of free moving animals, especially when they are hunting or being hunted. The primates, including human being, largely depend on the visual system to attain the information from outside world. Normally we define the retinal flow changes caused by self-motion as optic flow, which is an important cue for heading judgements. In natural conditions, eye/head rotations are common during self-motion. This will severely distort the radical image pattern of the retinal optic flow. However, we can still estimate the heading direction correctly. Therefore, the visual system must have a mechanism to compensate the eye movements and recover the real direction of self-motion. Unfortunately, the neuronal mechanism of eye movements compensation during self-motion are still unclear. We first conducted a series of behavioral experiments to test how eye movement speed, self-motion speed and visual signal reliability affect heading perception and eye movements compensation. The visual stimuli were generated by computer to simulate the retinal flow when the observer was moving towards a 3D cloud of points. Heading direction was varied along horizontal line. The participants were asked to report the perceived heading direction, either left or right. In real eye movements condition, the subject was required to pursuit moving target with their eyes. In simulated eye movements condition, subjects had to hold their gaze at fixation point but was presented with visual stimuli combined the effects of pursuit eye movements. In another word, the distortion on retinal flow cause by pursuit eye movement was superimposed on each heading stimulus to keep the retinal image equal, frame by frame, but no presence of extra-retinal signals. The error rate was used to evaluate the behavioral performance. We found that the levels of extra-retinal contributions increased with increasing pursuit speed (stronger extra-retinal signal), and with decreasing heading speed (weaker retinal signal). In addition, extra-retinal contributions also increased as we corrupted retinal signals with noise. Our results suggest that neural system can flexible integrate the retinal and non-retinal signal based on the reliability of the information and optimally percept the direction of self-motion.
|石金富. 自身运动中眼动补偿机制研究[D]. 北京. 中国科学院研究生院,2017.|
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