Geekathon, part two

It's sometimes remarked by scientists that the easy questions are the hardest. One of the very hardest is the mystery of consciousness, our awareness of ourselves. We know we exist: "I think, therefore I am." It's far more than a matter of sensory input: A bacteria can react to its environment. It's an internal, something within ourselves, something that deals in and incorporates the information provided by our senses but goes clearly beyond it.

It's so mysterious - so frustrating - that in fact some people denied it even existed. But developments in neurology and neurological imaging continue to suggest a physical basis for consciousness. For example, WorldScience.net reports that

[i]n a study billed as an exploration into the realm of “consciousness,” researchers claim to have found brain cells that become very busy only when something is consciously noticed. ...

Volunteers were shown pictures on a computer screen very briefly - for a time just at the edge of being long enough to be noticeable. The participants were asked each time whether they saw the picture or not. Sometimes the exact same visual input was noticeable on one trial and not on another, for the same person, [lead researcher Rodrigo] Quian Quiroga [of the University of Leicester, UK,] said. ...

Certain neurons, or brain cells, “responded to the conscious perception in an ‘all-or-none’ way,” Quian Quiroga said: they dramatically changed their rate of firing signals, only when pictures were recognized. These neurons were in the medial temporal lobe, a region deep inside the brain often associated with memory.

For example, in one patient, a neuron in the hippocampus - a structure also in that area - “fired very strongly to a picture of the patient’s brother when recognized and remained completely silent when it was not,” Quian Quiroga said. ...

“[A] picture flashed very briefly generated nearly the same response - if recognized - as when shown for much longer periods of time.”

In other words, it was the recognition itself, not the length of time it was recognized, that produced the reaction. This is not, of course, a measure of consciousness itself, which still defies real understanding, much less analysis, but it does show the existence of specific physical mechanisms connected to a conscious - and that's the key point here, a conscious - awareness of the world around us. For the moment, neural scientists are having to content themselves with analyzing such physical mechanisms, but there is more than enough to do even there.

The article adds that potential applications of the work, even without considering the idea of explaining consciousness, include development of “neural prosthetic” devices that could enable paralyzed patients to operate a robotic limb by thinking about what they want it to do and the treatment of epilepsy, Alzheimer’s, and schizophrenia.