Speeding up visual discrimination learning in cats by differential exposure of positive and negative stimuli

We have developed an adaptive training method which considerably reduces the total time required to train cats to threshold in an orientation discrimination task. During training, the animals are given greater exposure in time to the positive stimulus compared to the negative one. Therefore, this method has been coined the differential exposure method (DEM). The greater exposure to the positive stimulus reduces the number of errors an animal commits during training and thereby enhances speed of learning. Indeed, with the DEM, 34 daily sessions sufficed to train cats to threshold for 2 different reference orientations. Furthermore, the DEM was effective not only for simple stimuli such as real bars but also for complex stimuli such as illusory contours. Finally, the DEM was equally effective for training naive cats which had undergone large visual cortical lesions as it was for normal animals.