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No. 36: Nov-Dec 1984

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Brains Not Hardwired

The prevalent conception of the brain compares it to a hardwired computer in which all the wires and components are all permanently soldered together. An equivalent situation would prevail in the brain if all sensory pathways and cells had fixed duties and memories to handle. If the portion of the brain dedicated to speech were damaged, as in a stroke, it could never repair itself. This dogma is now being challenged.

A pertinent line of brain research is now underway at the Coleman Laboratory of the University of California in San Francisco, where Michael Merzenich and his associates are studying the brains of monkeys.

"Merzenich's findings challenge a prevailing notion that most sensory pathways in the nervous system are 'fixed' or 'hardwired' by the maturation of anatomic connections, either just before or soon after birth. They also address the puzzling question of what forces may be at work when stroke victims partly recover. Do 'redundant copies' of skills exist outside the damaged regions, or is physical damage within the brain repaired over time? Or can old skills be newly established in different, undamaged brain regions."

Apparently the brain should really be compared with a reprogrammable computer. Perhaps the brain even stores duplicates of critical "programs"; i.e., skills. Merzenich's findings go even farther. He finds that the parts of the brain associated with certain skills or data processing move and change shape spontaneously. The brain, it seems, continually reorganizes itself. Fading fast is the idea that each data point is recorded in a specific cell or neuron interconnection.

(Fox, Jeffrey L.; "The Brain's Dynamic Way of Keeping in Touch,: Science, 225:820; 1984.)

From Science Frontiers #36, NOV-DEC 1984. � 1984-2000 William R. Corliss