Saturday, September 22, 2007

Consciousness without a cerebral cortex

It’s bizarre how it’s ok to withhold food and water to a person who has a working brain stem but not much else. But to starve and dehydrate an animal without much more than a brain stem and this is considered cruel.

Self-awareness and other "higher" forms of thought may require cortical contributions. But Merker posits that "primary consciousness," which he regards as an ability to integrate sensations from the environment with one's immediate goals and feelings in order to guide behavior, springs from the brain stem.

If he's right, virtually all vertebrates—which share a similar brain stem design—belong to the "primary consciousness" club. Moreover, medical definitions of brain death as a lack of cortical activity would face a serious challenge. At the very least, physicians could no longer assume that individuals with hydranencephaly don't need pain medication or anesthesia during invasive medical procedures. (Consciousness without a cerebral cortex: A challenge for neuroscience
and medicine
)

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