Functional role of the sensory cortex in learning motor skills in cats.

The functional role of corticocortical input projecting to the motor cortex in learning motor skills was investigated by training 3 cats with and without the projection area. After unilateral removal of areas 1, 2, 2 praeinsularis and a part of 5, the cat was placed in a box and trained to pick up a small piece of food from a beaker in front of the box. Since the beaker and the edge of the box had a space in between, the cat had to develop a new motor skill to being the food back to the box across the space. This skill consisted of combined supination and flexion of the paw to hold the food over the gap. In all 3 cats, the training period necessary for acquisition of the motor skill for the forelimb contralateral to the lesioned brain was significantly longer than the period necessary for the forelimb ipsilateral to the lesioned cortex. Ablation of the remaining projection area after completion of the training did not impair the learned motor skill. The results suggest that the input from the lesioned area to the motor cortex participates in learning motor skills.