Weber H, Aiple F, Fischer B, Latanov A
Department of Neurophysiology, University of Freiburg, Federal Republic of Germany.
Exp Brain Res. 1992;89(1):214-22. doi: 10.1007/BF00229018.
The saccadic eye movements of three humans and one non-human primate (a male rhesus monkey) have been measured for target eccentricities between 0.3 and 15 deg. With a gap task (fixation point offset precedes target onset by 200 ms) and a target at 4 deg, all subjects produced reasonable amounts of express saccades as indicated by a clear peak in the distribution of their saccadic reaction times (SRT): about 100 ms in human subjects and 70 ms in the monkey. This peak disappeared with decreasing target eccentricity below 2 deg, but saccades of longer (regular) reaction times were still present. Thus it was found that there exists a dead zone for express saccades. In addition, small saccades have a much stronger tendency to overshoot the target and their velocity falls above the main sequence as defined by the least square fit of an exponential v = vo(1-exp(-a/ao)) to the maximal velocity (v) versus amplitude (a) relationship (vo and ao are constants fitted). It is concluded that for small saccades the express way is blocked functionally or does not exist anatomically.
已对三名人类和一只非人类灵长类动物（一只雄性恒河猴）在目标偏心度为0.3至15度之间的扫视眼动进行了测量。在间隙任务（注视点偏移比目标出现提前200毫秒）且目标位于4度的情况下，所有受试者都产生了适量的快速扫视，这由其扫视反应时间（SRT）分布中的明显峰值表明：人类受试者约为100毫秒，猴子约为70毫秒。随着目标偏心度降至2度以下，该峰值消失，但仍存在反应时间较长（常规）的扫视。因此发现快速扫视存在一个盲区。此外，小幅度扫视有更强的过冲目标倾向，并且其速度高于通过指数v = vo(1 - exp(-a/ao))对最大速度（v）与幅度（a）关系进行最小二乘拟合所定义的主序列（vo和ao为拟合常数）。得出的结论是，对于小幅度扫视，快速通道在功能上被阻断或在解剖学上不存在。
