Sridhar Deepika, Bedell Harold E
College of Optometry, University of Houston, 505 J Armistead Building, Houston, TX 77204, USA.
Perception. 2013;42(2):127-37. doi: 10.1068/p7280.
The Wells-Hering's laws of perceived egocentric visual direction (EVD) assume that information about eye position includes equal contributions from both eyes. An implication of this assumption is that only versional eye movements should lead to a change in perceived EVD. Previously, we showed that a differential weighting of eye-position information occurs in some individuals during asymmetric vergence. To extend this finding, we determined here whether a differential weighting of eye-position information occurs also during symmetric vergence eye movements. Open-loop pointing responses to a bright target were obtained in five subjects to estimate the contribution of each eye's position information to perceived EVD during symmetric vergence demands that ranged from 6 prism diopters base in to 18 prism diopters base out. In all five subjects, the slopes of the lines fit to the pointing responses were in the direction that was predicted from an unequal weighting of eye-position information. We conclude that symmetric vergence movements can result in a change in perceived visual direction, contrary to an assumption of the Wells-Hering's laws.
威尔斯-赫林关于自我中心视觉方向（EVD）的定律假定，关于眼位的信息在双眼的贡献相等。这一假设的一个推论是，只有版本性眼动才会导致感知到的EVD发生变化。此前，我们发现，在不对称性聚散过程中，一些个体存在眼位信息的差异加权。为了扩展这一发现，我们在此确定了在对称性聚散眼动过程中是否也会出现眼位信息的差异加权。在五名受试者中获得了对明亮目标的开环指向反应，以估计在从6棱镜度内聚到18棱镜度外聚的对称性聚散需求期间，每只眼睛的位置信息对感知到的EVD的贡献。在所有五名受试者中，拟合指向反应的直线斜率方向与眼位信息不等加权所预测的方向一致。我们得出结论，与威尔斯-赫林定律的假设相反，对称性聚散运动可导致感知视觉方向的改变。
