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Evaluation of a Neural Network Model of Amnesia in Diffuse Cerebral Atrophy

Published online by Cambridge University Press:  02 January 2018

James R. G. Carrie*
Affiliation:
Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, and Psychiatry Service, Houston VAMC, 2002 Holcombe, Houston, Texas 77030, USA

Abstract

A digital computer program generating a simulated neural network was used to construct a model which can show behaviour resembling human associative memory. The experimental network uses distributed storage, and, in this respect, its functional organisation resembles that suggested by reported observations of neuronal activity in the human temporal lobe during memory storage and recall. Inactivation of increasing numbers of randomly distributed network units simulated advancing cerebral atrophy. This caused progressive impairment of performance, resembling the gradual deterioration of memory function observed in chronic diffuse cerebral degeneration. Unit inactivation had similar effects on recall whether the same units were inactivated before or after learning. This differs from most relevant observations of amnesia resulting from diffuse cerebral disease. While the model may functionally resemble long-term information storage sites in the brain, other cerebral mechanisms participating in learning and remembering are also damaged by diffuse cerebral atrophy.

Type
Research Article
Copyright
Copyright © Royal College of Psychiatrists, 1993 

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References

Beatty, W. W., Salmon, D. P., Butters, N., et al (1988) Retrograde amnesia in patients with Alzheimer's disease or Huntington's disease. Neurobiology of Aging, 9, 181186.CrossRefGoogle ScholarPubMed
Crick, F. (1989) The recent excitement about neural networks. Nature, 337, 129132.CrossRefGoogle ScholarPubMed
Damasio, A. R., Eslinger, P. J., Damasio, H., et al (1985) Multimodal amnesic syndrome following bilateral temporal and basal forebrain damage. Archives of Neurology, 42, 252259.CrossRefGoogle ScholarPubMed
Dudai, Y. (1989) The Neurobiology of Memory. New York: Oxford University Press.Google Scholar
Hebb, D. O. (1949) Organization of Behavior. New York: Wiley.Google Scholar
Heit, G., Smith, M. E. & Halgren, E. (1988). Neural encoding of individual words and faces by the human hippocampus and amygdala. Nature, 333, 773775.CrossRefGoogle ScholarPubMed
Hopfield, J. J. (1982) Neural networks and physical systems with emergent collective computational abilities. Proceedings of the National Academy of Science, 79, 25542558.CrossRefGoogle ScholarPubMed
Jorgensen, C. C. & Matheus, C. J. (1986) Catching knowledge in neural nets. Al Expert, 1, 3038.Google Scholar
Kopelman, M. D. (1989) Remote and autobiographical memory, temporal context memory, and frontal atrophy in Korsakoff and Alzheimer patients. Neuropsychologia, 27, 437460.CrossRefGoogle ScholarPubMed
Lazare, B. (1973) Hidden conceptual models in clinical psychiatry. New England Journal of Medicine, 288, 345351.CrossRefGoogle ScholarPubMed
Miall, R. C. (1989) The diversity of neuronal properties. In The Computing Neuron (eds Durbin, R., Miall, R. C. & Mitchison, G. J.), pp. 1134. Wokingham: Addison-Wesley.Google Scholar
Mishkin, M. (1982) A memory system in the monkey. Philosophical Transactions of the Royal Society, London, Series B, 298, 8595.Google ScholarPubMed
Mishkin, M. & Appenzeller, T. (1987) The anatomy of memory. Scientific American, 256, 6271.CrossRefGoogle ScholarPubMed
Reggia, J. A. (1988) Artificial neural systems in medical science and practice. MD Computing, 5, 46.Google ScholarPubMed
Rolls, E. T. (1989) The representation and storage of information in neural networks in the primate cerebral cortex and hippocampus. In The Computing Neuron (eds Durbin, R., Miall, R. C. & Mitchison, G. J.), pp. 125159. Wokingham: Addison-Wesley.Google Scholar
Rumelhart, D. E. & McClelland, J. L. (1986) PDP models and general issues in cognitive science. In Parallel Distributed Processing, Vol. 1 (eds Rumelhart, D. E., McClelland, J. L. & The PDP Research Group), pp. 110146. Cambridge, Mass.: MIT Press.CrossRefGoogle Scholar
Sagar, H. J., Cohen, N. J., Sullivan, E. V., et al (1988) Remote memory function in Alzheimer's disease and Parkinson's disease. Brain, 111, 185206.CrossRefGoogle ScholarPubMed
Squire, L. R. (1986) Mechanisms of memory. Science, 232, 16121619.CrossRefGoogle ScholarPubMed
Squire, L. R. (1987) Memory: neural organization and behavior. In Handbook of Physiology, Section 1, Vol. 5, Part I: The Nervous System (eds Brookhart, J. M. & Mountcastle, V. B.), pp. 295371. Bethesda, MD: American Physiological Society.Google Scholar
Squire, L. R., Haist, F. & Shimamura, A. P. (1989) The neurology of memory: quantitative assessment of retrograde amnesia in two groups of amnesic patients. Journal of Neuroscience, 9, 828839.CrossRefGoogle ScholarPubMed
Squire, L. R., & Zola-Morgan, S. (1991) The medial temporal memory system. Science, 253, 13801386.CrossRefGoogle Scholar
Tank, D. & Hopfield, J. J. (1987) Collective computation in neuronlike circuits. Scientific American, 257, 104114.CrossRefGoogle ScholarPubMed
Wilson, R. S., Kaszniak, A. W. & Fox, J. H. (1981) Remote memory in senile dementia. Cortex, 17, 4148.CrossRefGoogle ScholarPubMed
Zola-Morgan, S. M. & Squire, L. R. (1990) The primate hippocampal formation: evidence for a time-limited role in memory storage. Science, 250, 288290.CrossRefGoogle ScholarPubMed
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