Word: braine
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Dates: during 1990-1999
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From these studies, Damasio, who is chairman of the University of Iowa's neurology department, concludes that consciousness is a layered edifice, like some Mayan pyramid or Mesopotamian ziggurat. It is based on an inchoate feeling of self that arises from the brain's detailed "diagram" of the body. Damasio says this diagram, which is continuously revised by the senses, can be thought of as the "protoself"; it props up the rest of the structure...
...there is another form of consciousness that embellishes one's image of self with a wealth of autobiographical detail. Damasio calls this extended consciousness, and it requires such a vast capacity for memory that it's probably special only to humans and great apes. Hence, damage to the brain's memory centers can impair a person's extended consciousness while leaving core consciousness intact...
Damasio cites the case of a young woman who at age 30, shortly after the birth of her second child, entered a netherworld of nonstop epileptic seizures. The seizures damaged a region of the brain called the hippocampus, so that afterward she could no longer recall the simplest things, like having put clothes in the washer or having given her kids permission to visit friends. For six years she has lived in a free-floating present, unable to form new memories or envision the future. Her extended consciousness has been sadly diminished...
...Damasio and his wife Hanna, his closest collaborator, such patients are windows into the brain. Their seizures, strokes and diseases, while damaging the hippocampus, leave core consciousness unimpaired. That's because it evolved much earlier than extended consciousness, Damasio says, and thus is dependent on more ancient structures, especially those located within the brain stem and hypothalamus. Among the most important: a large region called the cingulate cortex, which not only receives sensory input from the skin, muscles and internal organs but also sends out signals to initiate movement and focus attention, as when emotions send our blood pressure soaring...
Even so, Damasio doesn't regard any one region of the brain--or the brain as a whole--as the seat of consciousness. Instead he sees the brain as an interconnected system with cognition (language, memory, reason and emotion) and sensory processes (vision, hearing, touch and taste) centered in different areas. Consciousness, he says, is similarly dispersed...