The human brain stores and retrieves enormous amounts of information every waking moment. This organization, storage and retrieval of daily events is obviously essential to our existence and limitations in this capacity, either naturally occurring or resulting from disease, is devastating to the life of the sufferer. There appears to be particular parts of the brain that play special roles in these processes because there are brain injuries that often selectively disrupt learning or memory. It is critical for our understanding of the brain to identify these structures, determine how they work in relation to other brain areas and what they are doing that their damage will produce learning or memory disorders. Also, symptoms of learning and memory disorders produced by brain damage have been key elements in constructing models of normal learning. We have developed methods for using cold to make reversible lesions in different brain areas so that we can study this process in the awake, behaving monkey. We can suppress the function of a localized region of the brain, measure its effects on tests of learning and memory and then remove the cold and allow the area to return to normal so that we can then prepare the animal for a different task or a different lesion. This way we can control the flow of information through the brain, blocking it at certain points, observe what the block does and then move the block to a different spot and test again. Ultimately we hope to discover the mechanisms that underlie the extraordinary capacity of the human brain to manage information.
