Neuroanatomy of memory and amnesia: a case for multiple memory systems.
Several different dissociable memory systems are considered in terms of their known or putative sites of pathology. In man, short-term memory can be selectively impaired by left hemisphere lesions near the acoustic projection area. There may be other modality-specific deficits. Long-term memory is considered in terms of a) knowledge systems, b) stable associative memory; c) priming, and d) event memory, with special reference to the amnesic syndrome. For each of these categories, clinical neuropathological and relevant animal evidence is reviewed. It is concluded that "memory" is not holistic, and the anatomical bases must be considered independently for each of the several dissociable (but normally interacting) systems. Some are likely to involve virtually all levels of the nervous system, while others are highly specific.