Amnestic Confusional Phenomena, Hippocampal Stimulation, and Laterality Factors

Abstract

The association between hippocampal function and phenomena of consciousness is usually indirectly inferred, i.e., through clinicopathological observations, in contrast to direct laboratory observations, of the involvement of limbic structures in seizures and seizure related disorders of consciousness in man. Equally, the association between hippocampal functions and memory is usually inferred through observations of memory impairment in man with hippocampal damage (Grunthal, 1947; Glees and Griffith, 1952). However, direct or experimental evidence of these associations is, understandably, rare in man. Only through the utilization of opportunities provided by legitimate diagnostic or therapeutic procedures, such as depth implantation for electrical recording and stimulation of epileptic patients with uncontrollable seizures considered for neurosurgery, can such evidence be obtained (Penfield and Jasper, 1954; Bickford et al., 1958). The following chapter deals first with background data relevant to the quest, then presents direct evidence of the experimental type mentioned above and finally discusses the implications of the evidence for cerebral lateralization and clinical syndromes of the literature.