ABSTRACT
This chapter focuses on a condition that has been traditionally referred to as a loss of memory. Clinicians recognize two main forms of amnesia— anterograde and retrograde amnesia. Anterograde amnesia pertains to a person's inability to recall ongoing experiences subsequent to some disease, trauma, or other affliction, whereas a retrograde amnesia applies to a failure to remember experiences throughout a particular period prior to such an affliction. The possible role of the hippocampal formation in memorative functions began to attract wider interest in 1958 when W. Penfield and B. Milner reported two cases of severe anterograde amnesia following unilateral extirpation of a large part of the hippocampal formation for the treatment of psychomotor epilepsy. Since the recognition that the limbic structures of the temporal lobe are implicated in memorative functions, numerous experiments have been performed on rats, cats, dogs, and monkeys in an attempt to define the nature of the deficit and to identify specific structures involved.
