Cerella J
Veterans Administration Outpatient Clinic, Boston, MA 02108.
Perception. 1990;19(2):141-59. doi: 10.1068/p190141.
Two experiments are reported in which the response of pigeons to perspective transformations of a pattern target was measured. In the first experiment an alphabet letter was taken as the pattern target (the 'positive') and the response to its perspective transforms was compared to the response to nontarget letters ('negatives') over the course of discrimination training. In the second experiment irregular quadrilaterals were used as positives and the responses to slight perspective deformations of the prototypes were compared to the responses to random transformations of the same magnitude under steady-state conditions. The amount of differential responding depended on the type of transformation. There was no differential response to targets rotated in the picture plane or around the horizontal axis in either experiment. There was differential response to small reductions and enlargements of the target. There was also differential response to translated targets, and this was seen irrespective of the amount of displacement. Results from targets rotated around the vertical axis were erratic, some target-plus-angle combinations elicited differential responding, but most did not. The erratic responses are attributed to symmetries in pattern elements that were abstracted as critical features. Pigeons therefore exhibit no true rotation invariance, limited size invariance, and complete shift invariance. It is argued that size invariance, but not position invariance, may depend on prior exposure to the alternatives.
本文报告了两项实验，其中测量了鸽子对图案目标透视变换的反应。在第一个实验中，将一个字母表字母作为图案目标（“正例”），并在辨别训练过程中，将其透视变换的反应与对非目标字母（“负例”）的反应进行比较。在第二个实验中，使用不规则四边形作为正例，并在稳态条件下，将对原型轻微透视变形的反应与对相同幅度随机变换的反应进行比较。差异反应的程度取决于变换的类型。在任何一个实验中，对在画面平面内或绕水平轴旋转的目标都没有差异反应。对目标的小幅缩小和放大有差异反应。对平移后的目标也有差异反应，且无论位移量如何都能观察到。绕垂直轴旋转的目标的结果不稳定，一些目标加角度组合会引发差异反应，但大多数不会。不稳定的反应归因于被抽象为关键特征的图案元素中的对称性。因此，鸽子没有表现出真正的旋转不变性、有限的大小不变性和完全的位移不变性。有人认为，大小不变性而非位置不变性可能取决于之前对各种选项的接触。
