Reduction of lesion-induced deficits in visual reversal learning following cross-modal training.

Two experiments examined the effects of postoperative auditory intensity training on serial brightness reversal learning of visual decorticate rats. In Experiment 1 rats learned an avoidance response cued by a high intensity light prior to visual decortication. Six days later the rats were given either avoidance training with an auditory intensity cue, additional training with the preoperative visual cue, or no training. The next day all rats began a series of 8 brightness discrimination reversals. The no-training lesion group failed the early reversals but reached criterion in later reversals. Lesion rats retrained with visual cues failed early reversals with the low intensity light cue but not reversals with the high intensity cue. In contrast, lesion rats given auditory training easily reached criterion in all reversals. Experiment 2 followed a similar training sequence except auditory training was given after the second reversal. All rats showed rapid acquisition of all visual reversals subsequent to auditory training. These data suggest that generalization of a learning set by cross-modal transfer training with an intact modality can reduce reversal learning deficits following brain damage more efficiently than comparable training with the damaged system.