SUPPRESSION OF SENSITIVITY TO SURROUND DISPLACEMENT DURING VERGENCE EYE-MOVEMENTS
SUPPRESSION OF SENSITIVITY TO SURROUND DISPLACEMENT DURING VERGENCE EYE-MOVEMENTS
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DOI：
10.1016/0014-4886(89)90133-7
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发表时间：
1989-09-01
影响因子：
5.3
通讯作者：
SEMMLOW, JL
中科院分区：
文献类型：
--
作者：
HUNG, GK;WANG, TJ;SEMMLOW, JL
通过测量三名人类观察者对短暂(20ms)同时垂直位移(最高可达0.5度)的敏感度损失，对抑制进行了心理生理研究。在4度期间的水平线。会聚眼球运动。采用两种选择的强迫选择程序，其中刺激在试验的第一部分或第二部分呈现。移位脉冲的幅度、脉冲相对于收敛开始的时间以及试验中呈现刺激的部分被随机化。结果表明，抑制在会聚开始前约200ms开始，并持续到会聚开始后350ms，最大损失出现在会聚开始后25~125ms。最大灵敏度损失约为0.25~0.30个对数单位。由于外围因素通过使用简短的刺激呈现和偏心放置的周围环境来最小化，所发现的抑制主要归因于中枢神经机制。最后，收敛运动初始阶段对脉冲位移敏感性的抑制与最近发展的收敛系统的双模模型是一致的，在该模型中，阶跃响应的初始瞬时部分是预先编程的，而最终持续部分是通过连续反馈控制来维持的。
Suppression was investigated psychophysically in three human observers by measuring their loss of sensitivity to brief (20 ms) simultaneous vertical displacement (up to 0.5.degree.) of horizontal lines during 4.degree. covergence eye movements. A two-alternative forced choice procedure was used in which the stimulus was presented either in the first or second portion of a trial. The amplitude of the displacement pulse, the time of the pulse relative to convergence onset, and the portion of a trial in which the stimulus was presented were randomized. The results showed that suppression began about 200 ms before, and continued until 350 ms after, convergence onset with maximum loss occurring at 25 to 125 ms after convergence onset. The maximum sensitivity loss was about 0.25 to 0.30 log units. Since peripheral factors were minimized by the use of a brief stimulus presentation and an eccentrically placed surround, the suppression found was primarily attributed to central neural mechanisms. Finally, the suppression of sensitivity to pulse displacement during the initial phase of the vergence movement is consistent with a recently developed dual-mode model of the vergence system, in which the initial transient portion of a step response is preprogrammed whereas the final sustained portion is maintained by continuous feedback control.