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The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science is a book on neuroplasticity by psychiatrist and psychoanalyst Norman Doidge, M.D. It features numerous case studies of patients suffering from neurological disorders and details how in each case the brain adapts to compensate for the disabilities of the individual patients, often in unusual and unexpected ways. Interviews with the patients, clinicians, and research scientists involved in these studies make up a large portion of the contents. Doidge uses examples of previous work carried out by neuroscientists such as Paul Broca, Sigmund Freud, Aleksandr Luria, Donald O. Hebb, Paul Bach-y-Rita, and Eric Kandel to show that the brain is adaptive, and thus plastic. Through the case studies, Doidge demonstrates both the beneficial and detrimental effects that neuroplasticity can have on a patient, saying, "...neuroplasticity contributes to both the constrained and unconstrained aspects of our nature." However, neuroplasticity "...renders our brains not only more resourceful, but also more vulnerable to outside influences."
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An important example of neuroplasticity is how humans gain skills. Doidge presents an experiment performed by Alvaro Pascual-Leone in which he mapped the brains of blind people learning to read Braille. Braille reading is a motor activity, which involves scanning with a reading finger, and a sensory activity, which involves feeling the raised bumps. The brain maintains a representation of these sensory and motor aspects, which are located in different cortices. The blind subjects practiced two hours a day, Monday through Friday, with an hour of homework. The mapping of their brains took place on Monday, after the weekend, and Friday, immediately after their week cram. What the scans ultimately showed is that the maps dramatically increased in size on Friday scans but returned to a "baseline" size on the following Monday. It took 6 months for the baseline Monday map to gradually increase and by 10 months they plateaued. After the blind subjects took a two month break, they were remapped, and their maps were unchanged from their last Monday mapping. What this shows is that long lasting changes as the result of skill learning took 10 months of repeated practice. The reason why short-term improvements were made based on the Friday mappings, but eventually disappeared, is the result of the type of neuronal connections that were taking place. The Friday mappings were the result of the strengthening of existing neuronal connections. Monday mappings, though showing little progress initially and plateauing at ten months, were the result of the creation of new neural connections.
- ^ Doidge, N. The Brain That Changes Itself, Appendix 2, p. 318.
- ^ Doidge, N. The Brain That Changes Itself, Preface, p. xx.
- ^ Pascual-Leone, A., R. Hamilton, J.M. Tormos, J.P. Keenan, and M.D. Catala. 1999. Neuroplasticity in the adjustment to blindness. In J. Grafman and Y. Christen, eds., Neuronal plasticity: Building a bridge from the laboratory to the clinic. New York: Springer-Verlag, pp. 94-108.
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