Zeevi Y Y, Wetzel P A, Geri G A
Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa.
Vision Res. 1988;28(10):1145-55. doi: 10.1016/0042-6989(88)90141-1.
Saccaadic response preferences and latencies were measured using dual targets presented at 5, 10 and 15 deg along the horizontal meridian in either one or both visual hemifields. In the unihemifield condition, subjects exhibited a strong preference (about 95%) in favor of the target presented closer to the original fixation point. Further, the presence of the second target did not increase the response latency to the preferred target. In the bihemifield condition using spatially symmetric targets, directional preference varied across subjects from 57 to 100% (mean = 83%). There was also a significant increase in response latency as compared with responses to either single targets or dual targets presented in one hemifield. This latency increase was observed for responses in both the preferred and nonpreferred directions and was taken as evidence of mutual interaction between the two hemispheres. The response preferences could be eliminated by delaying the onset of the preferred target by about 100 msec in the unihemifield condition and by about 50 msec in the bihemifield condition. Further, the interactions between the effects of the targets on response time in the bihemifield condition were found to be asymmetrical in that a target presented in the preferred hemifield has a greater effect than a target in the nonpreferred hemifield on responses to targets presented in the counterhemifield. The results suggest an asymmetry in hemispheric interaction which has not previously been demonstrated in the visualoculomotor system.
使用沿水平子午线在5度、10度和15度处呈现于一个或两个视觉半视野中的双目标来测量扫视反应偏好和潜伏期。在单半视野条件下，受试者对更靠近原始注视点呈现的目标表现出强烈偏好（约95%）。此外，第二个目标的存在并未增加对偏好目标的反应潜伏期。在使用空间对称目标的双半视野条件下，不同受试者的方向偏好从57%到100%不等（平均 = 83%）。与对单目标或在一个半视野中呈现的双目标的反应相比，反应潜伏期也有显著增加。在偏好和非偏好方向的反应中均观察到这种潜伏期增加，这被视为两个半球之间相互作用的证据。在单半视野条件下将偏好目标的起始延迟约100毫秒，在双半视野条件下延迟约50毫秒，可以消除反应偏好。此外，发现在双半视野条件下目标对反应时间的影响之间的相互作用是不对称的，即偏好半视野中呈现的目标对反半视野中呈现的目标的反应的影响大于非偏好半视野中的目标。结果表明半球相互作用存在不对称性，这在视觉动眼系统中以前尚未得到证实。
