When human beings sustain a stroke, traumatic head injury or neurotoxic poisoning, they may suffer from "organic amnesia" -- a form of memory loss resulting from damage to the brain. Clinical studies of these people have increased our understanding of normal memory in two ways. First, we have been able to identify many of the brain structures involved in memory. Second, we are better able to understand some of the basic mechanisms of memory as we learn what causes it's malfunction. Animal models of organic amnesia have furthered our understanding of memory because the conditions leading to such memory deficits can be more carefully controlled. Studies of animal memory often cannot be compared directly to human memory, in part because the information we ask animals to remember may bear but little meaning to their lives. In their recent studies, Drs. Eichenbaum and Cohen have shown that rodents possess exceptionally good abilities in learning about odors. In fact, their olfactory learning capabilities may be as powerful as are visual memories of humans and monkeys. In these studies, Drs. Eichenbaum and Cohen will utilize rodents' striking olfactory learning capacities to: (1) develop new and more powerful memory tasks similar to those used so successfully in monkeys and humans, (2) use these tasks to test whether rats demonstrate amnesia as humans do after damage to specific brain structures, and (3) employ variations of these tasks to clarify how memories are encoded within specific brain regions. The results should indicate whether the qualities of memory are the same in humans and in animals. In addition, their results may help in the search for treatments of memory loss.
