More from Tanya Lewis in Livescience.com (“Scientists closing in on theory of Consciousness”)
“Correlates of consciousness
In the last few decades, neuroscientists have begun to attack the problem of understanding consciousness from an evidence-based perspective. Many researchers have sought to discover specific neurons or behaviors that are linked to conscious experiences.
Recently, researchers discovered a brain area that acts as a kind of on-off switch for the brain. When they electrically stimulated this region, called the claustrum, the patient became unconscious instantly. In fact, Koch and Francis Crick, the molecular biologist who famously helped discover the double-helix structure of DNA, had previously hypothesized that this region might integrate information across different parts of the brain, like the conductor of a symphony.
But looking for neural or behavioral connections to consciousness isn’t enough, Koch said. For example, such connections don’t explain why the cerebellum, the part of the brain at the back of the skull that coordinates muscle activity, doesn’t give rise to consciousness, while the cerebral cortex (the brain’s outermost layer) does. This is the case even though the cerebellum contains more neurons than the cerebral cortex.
Nor do these studies explain how to tell whether consciousness is present, such as in brain-damaged patients, other animals or even computers . [Super-Intelligent Machines: 7 Robotic Futures]
Neuroscience needs a theory of consciousness that explains what the phenomenon is and what kinds of entities possess it, Koch said. And currently, only two theories exist that the neuroscience community takes seriously, he said.”