猫对方位辨别的知觉学习

观察了猫对光栅方位辨别的知觉学习。两只成年猫(cat1和cat2)先单眼辨别方位差为30度角的两个正弦光栅以获得食物奖赏。当辨别正确率达80%以上后,猫开始学习用单眼辨别夹角连续变化的两个正弦光栅,采用二进一递进训练方法(two-correct down/one-error up staircase method,即猫连续两次辨别正确,则待辨别的两个光栅的方位差降低为原来的0.9倍;如果辨别错误一次,则方位差增加至原来的1.1倍)追踪猫可辨别的光栅方位差。在训练前后分别检测训练眼和非训练眼对不同方位差(2°,4°,6°,8°,10°,12°,16°,20°,24°,30°)光栅辨别的正确率。结果显示:对于固定方位差光栅的辨别学习,学习效果能完全传递给非训练眼;但对方位差连续减小的光栅辨别,两眼间几乎没有传递。提示固定方位角和连续变化方位角光栅的辨别学习可能由不同的信息处理机制介导。

Perceptual Learning of Grate Orientation Discrimination in Cats(in English)

Perceptual learning of orientation discrimination was investigated using cats. Two adult cats (Cat 1 and 2) were trained to monocularly discriminate between two static striped sinusoidal grates with 30° orientation difference. After greater than 80% correct performance was reached, cats were then required to monocularly perform a discrimination between two grates with consecutively shifting orientation difference(2°, 4°, 6°, 8°, 10°, 12°, 16°, 20°, 24°, 30°) . The staircase method (two correct-down and one error-up) was applied throughout the training to track the threshold of orientation difference that cats could detect. The performance of detecting grates with varied orientation difference was measured respectively for both trained and untrained eyes before and after training. Our results showed that the learning effect of discrimination for grates with a fixed orientation difference transferred completely from the trained eye to the untrained eye, whereas the inter-eye transfer for detecting grates with gradually reducing orientation difference was almost nonegrates. The two opposite learning effects in the same subject strongly suggest that different information processing mechanisms might mediate the learning processes.