Transfer after pretraining with the negative stimulus

Two groups of rats trained in the jumping stand acquired a horizontal stripes vs. vertical stripes discrimination and then learned its reversal. The groups differed in their pretraining. One group had previously learned a black vs. white discrimination; the other a discrimination in which the S- was the same as that used in the horizontal against vertical problem. S- pretraining facilitated not only acquisition but also the reversal of the orientation discrimination thereby confirming a prediction that reversal learning will be rapid when the original problem is learned chiefly in terms of the S-. It is suggested that overtraining may facilitate reversal learning, in some cases at least, by inducing animals to concentrate on the S-.