Abstract
Psychological and electroencephalographic study was made on memory disturbance in the various cloudy states of consciousness induced by electroconvulsion or injection of some hypnotic drugs (chlorpromazine, amobarbital sodium etc.). The experiments were carried out in fourty-eight psychiatric Patients, none of whom showed memory disturbance in a previous examination. The results of the experiments were compared with those of similar study in the clear state of consciousness in five cases of organic dementia.
These patients, lying on bed with eyes closed, were examined by a series of memory tests, e. i. a reproduction of short sentences, a digit-span test, and a paired-associate method, while the verbal responces, G. S. R. and E. E. G. wererecorded concomitantly.
In the clouded state of consciousness, the memorizing ability (immediate memory) could be fairly correlated with the appearance and continuance of arousal responces of E. E. G. evoked by the test-stimuli, whereas the duration of retention seemed to be determined by the excitation level of E. E. G. or the depth of disturbance of consciousness.
In the recall of memory, distinct differences were observed between the drug-induced somnolence and the post-convulsive state. In the former case the recall colud be obtained so far as it was accompanied by activation patterns, but in the latter the recall was apparently independent of the continued appearence of arousal responses, and was easily blocked by other distracting stimuli. Similar results to the post-convulsive state was found in the experiments of organic dement cases.
These findings in the drug-induced somnolence suggest the importance of the arousal and maintenance of attention for the memory activity, and can be considered in relation to the brain-stem functions. On the other hand, the recall defect in the post-convulsive state and the organic dementia can be ascribed to the disturbance of intellectual abilities or the integrating function of the cerebral cortex. (Author's abstract)
