THE DIFFERENTIAL ROLE OF THE CEREBRAL CORTEX IN CLASSICAL AND INSTRUMENTAL CONDITIONING

Previous experiments (Bures & Buresöva, I960, Russell & Oehs, 1960) have shown that spreading cortical depression (SD) can be used as a technique to provide a functional split-brain preparation. Repeated waves of SD generated in one cortical hemisphere were found to depress cortical function for many hours. During this time rats were exposed to various instrumental conditioning procedures. Typically testing revealed that such conditioning during unilateral SD resulted in the formation of a unilateral memory trace, restricted to the hemisphere functional during training. No such retention of learning was found in the hemisphere that .had been depressed during training. These results indicate the cortex is involved in the storage of instrumental conditioning.