Bridgeman B, Graziano J A
Program in Experimental Psychology, University of California, Santa Cruz 95064.
Vision Res. 1989;29(12):1729-36. doi: 10.1016/0042-6989(89)90155-7.
Bias in efferent commands to the eye changes the apparent straight ahead direction in an unstructured visual field, but has little effect in a normal visual environment. Naive subjects set a visible marker to appear straight ahead under monocular viewing conditions and while pressing on the viewing eye. Three background conditions were used: a naturalistic landscape photograph, a blank field, and a repeating checkerboard texture that provides strong contours but no information about visual direction. Effect of eyepress on straight-ahead judgments was small but significant with the landscape background, and larger with the blank field; the checkerboard texture yielded a bias halfway between the magnitudes of bias in the other two conditions. A visual capture theory predicts that the textured field should work like a blank one, while an oculomotor theory predicts that it should work like a natural one. Interpreted in this context, the results show the two theories to be about equally important in judging straight ahead. A second experiment with experienced observers and moving backgrounds gave the same result.
传出至眼睛的指令偏差会在无结构视野中改变视直向前方向，但在正常视觉环境中影响甚微。未经过训练的受试者在单眼观察条件下并按压正在观察的眼睛时，将一个可见标记设置为视直向前。使用了三种背景条件：一张自然风景照片、一个空白视野和一个重复的棋盘格纹理，该纹理提供了强烈的轮廓但没有关于视觉方向的信息。按压眼睛对视直向前判断的影响在有风景背景时虽小但显著，在空白视野时更大；棋盘格纹理产生的偏差大小介于其他两种条件的偏差之间。一种视觉捕获理论预测，有纹理的视野应该像空白视野一样起作用，而一种动眼神经理论预测，它应该像自然视野一样起作用。在此背景下进行解释，结果表明这两种理论在判断视直向前时同样重要。一项针对有经验的观察者和移动背景的第二个实验也得出了相同的结果。
