Retention deficits produced in monkeys with reversible cold lesions in the prestriate cortex

Cryodes were implanted over the prelunate and fusiform gyri in 4 monkeys. The intention was to block the prestriate projection to the inferotemporal cortex (IT). Cooling this cortex produced deficits that were completely reversed by removing the cold. The deficits appeared in the recall of visual discriminations that were learned prior to the application of the cold, but new discriminations were learned during cooling at the same rate as in control animals. This closely resembles the results of ablation experiments in this same cortex. There was no deficit when cooling this area on a delayed match-to-sample (DMS) task that required the animals to hold visual information over delays of 10 or 45 s. However, performance was close to chance during cooling when the delays were 6 min. With this long delay, when cooling was done separately at sample when the stimulus is received, or at match when the information is recalled, a significant deficit occurred only at match. The results are consistent with the suggestion that this area is involved in retrieval of visual information from long-term memory.