Nakamizo S, Shimono K, Kondo M, Ono H
Department of Psychology, Fukuoka University of Education, Japan.
Perception. 1994;23(9):1037-48. doi: 10.1068/p231037.
Visual directions of the two stimuli in Panum's limiting case with different interstimulus and convergence distances confirmed the predictions from the reformulated Wells-Hering's laws of visual direction. In experiment 1, six observers each converged on the midpoint of the interstimulus axis at 30, 60, and 90 cm from the eyes and adjusted a probe on the fixation plane to be in the same visual direction as that of each stimulus. Visual direction of the far stimulus was always nonveridical whereas that of the near stimulus was veridical only when its retinal disparity was small. In experiment 2, three observers each converged on the intersection of mid-sagittal plane and (a) the frontoparallel plane of the near stimulus, (b) that of the midpoint between the two stimuli, or (c) that of the far stimulus. The midpoint of the interstimulus axis was 60 cm from the eyes. Visual direction of the far stimulus was veridical only with convergence at the far plane. Visual direction of the near stimulus was veridical with convergence at the near plane, and also, only when its retinal disparity was small, with convergence at the two other planes.
在不同刺激间距和辐合距离的潘诺极限情况下，两种刺激的视觉方向证实了重新阐述的韦尔斯 - 黑林视觉方向定律的预测。在实验1中，6名观察者分别在距离眼睛30厘米、60厘米和90厘米处，将视线辐合于刺激轴的中点，并在注视平面上调整一个探针，使其与每个刺激处于相同的视觉方向。远处刺激的视觉方向总是非真实的，而近处刺激的视觉方向只有在其视网膜视差较小时才是真实的。在实验2中，3名观察者分别将视线辐合于正中矢状面与（a）近处刺激的额平行面、（b）两个刺激之间中点的额平行面或（c）远处刺激的额平行面的交点处。刺激轴的中点距离眼睛60厘米。远处刺激的视觉方向只有在辐合于远处平面时才是真实的。近处刺激的视觉方向在辐合于近处平面时是真实的，并且同样只有在其视网膜视差较小时，在辐合于其他两个平面时才是真实的。
