Comparison of compound and cross-modal training on postoperative visual relearning of visual decorticate rats.

The effects of postoperative bimodal compound conditioning and cross-modal transfer of learning on behavior were compared by training rats prior to visual decortication to avoid shock with visual intensity cues. On Postop Day 6, rats were given avoidance training in one of three cue conditions: auditory intensity cues (cross-modal), paired auditory and visual cues (compound conditioning), or no cues (no-training control). On Postop Day 7 rats in the no-training control and the cross-modal transfer conditions were retrained with the visual discrimination while rats in the compound conditioning group were either retrained with the visual intensity cue or trained with the auditory intensity cue. Postoperative cross-modal transfer training enhanced visual relearning whereas bimodal compound conditioning interfered with relearning. However, compound conditioning facilitated subsequent auditory discrimination learning. These results support the notion of an injury-induced neurological bias that is increased after bimodal compound conditioning and reduced after cross-modal training. Potential implications for neurological rehabilitation are also discussed.