VISUALLY INDUCED ADAPTIVE-CHANGES IN PRIMATE SACCADIC OCULOMOTOR CONTROL SIGNALS
VISUALLY INDUCED ADAPTIVE-CHANGES IN PRIMATE SACCADIC OCULOMOTOR CONTROL SIGNALS
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DOI：
10.1152/jn.1985.54.4.940
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发表时间：
1985-01-01
影响因子：
2.5
通讯作者：
MILES, FA
中科院分区：
文献类型：
--
作者：
OPTICAN, LM;MILES, FA
扫视是用于改变视觉固定的快速眼球运动。正常的眼跳突然结束，眼跳后眼球漂移很少，但急性眼运动缺陷可能会导致眼跳后眼睛明显漂移。先前对患有周围眼运动缺陷的患者和猴子的研究表明，大脑可以抑制这种眼跳后漂移。响应于位置和/或速度误差的视觉和/或本体感觉反馈，可以抑制眼睛漂移。本研究试图描述抑制跳动后漂移的适应性机制。研究了七只恒河猴对全视野刺激的水平指数运动引起的眼跳后视网膜滑动的反应。经过几个小时与眼跳相关的视网膜图像滑动后，猴子的眼球运动出现了零延迟、补偿性眼跳后眼漂移。这种眼睛漂移在黑暗中仍然很明显，尽管较小（通常为先前扫视幅度的 15%，最大漂移为 8 度）。单独的视网膜滑动（没有图像的净位移）足以引起这些适应性变化，并且对向左和向右扫视的补偿是独立的。需要几天的时间才能完成适应，但恢复（在光明中）要快得多。这种适应能力在黑暗中的衰退非常缓慢。 3天后，眼漂移减少了不到50%。单指数曲线拟合来自五只动物的数据的适应时间过程的时间常数为采集时间为 35 小时，恢复时间为 4 小时，黑暗中腐烂至少为 40 小时。对眼跳的中枢神经支配的描述通常被简化为只有两个组成部分：脉冲和步长。据推测，通过调整脉冲与神经支配步骤的比率来抑制病理性跳动后漂移 (19, 26)。然而，我们发现眼漂移的时间常数受到适应刺激的时间常数的影响，这不能用扫视神经支配的简单脉冲步模型来解释。扫视神经支配的更真实的表示具有三个组成部分：脉冲、指数滑动和步骤。由这种脉冲-滑动-步进组合驱动的眼运动植物的四阶线性模型可以准确地模拟正常的眼跳。通过正确调整滑动和步进组件，也可以模拟长时间暴露于光诱导视网膜图像滑动后发生的眼跳。（摘要截断为 400 字）
Saccades are the rapid eye movements used to change visual fixation. Normal saccades end abruptly with very little postsaccadic ocular drift, but acute ocular motor deficits can cause the eyes to drift appreciably after a saccade. Previous studies in both patients and monkeys with peripheral ocular motor deficits have demonstrated that the brain can suppress such postsaccadic drifts. Ocular drift might be suppressed in response to visual and/or proprioceptive feedback of position and/or velocity errors. This study attempts to characterize the adaptive mechanism for suppression of postsaccadic drift. The responses of seven rhesus monkeys were studied to postsaccadic retinal slip induced by horizontal exponential movements of a full-field stimulus. After several hours of saccade-related retinal image slip, the eye movements of the monkeys developed a zero-latency, compensatory postsaccadic ocular drift. This ocular drift was still evident in the dark, although smaller (typically 15% of the amplitude of the antecedent saccade, up to a maximum drift of 8 degrees). Retinal slip alone, without a net displacement of the image, was sufficient to elicit these adaptive changes, and compensation for leftward and rightward saccades was independent. It took several days to complete adaptation, but recovery (in the light) was much quicker. The decay of this adaptation in darkness was very slow; after 3 days the ocular drift was reduced by less than 50%. The time constants of single exponential curve fits to adaptation time courses of data from five animals were 35 h for acquisition, 4 h for recovery, and at least 40 h for decay in darkness. Descriptions of the central innervation for a saccade are usually simplified to only two components: a pulse and a step. It has been hypothesized that suppression of pathological postsaccadic drift is achieved by adjusting the ratio of the pulse to the step of innervation (19, 26). However, we show that the time constant of the ocular drift is influenced by the time constant of the adapting stimulus, which cannot be explained by the simple pulse-step model of saccadic innervation. A more realistic representation of the saccadic innervation has three components: a pulse, an exponential slide, and a step. Normal saccades were accurately simulated by a fourth-order, linear model of the ocular motor plant driven by such a pulse-slide-step combination. Saccades made after prolonged exposure to optically induced retinal image slip could also be simulated by properly adjusting the slide and step components.(ABSTRACT TRUNCATED AT 400 WORDS)