Saturday, April 30, 2005

Fw: Wired News: Awareness: Mystery of the Mind

This was just relayed from a friend; Interesting, eh?

TUCSON, Arizona -- In the quest to make a brainpower computer, perhaps the biggest mysteries remains the most nebulous: Where does awareness come from? Can it be simulated? What does awareness by itself look like?

While the first question remains unanswered, Rodney Brooks of MIT presented new research on robot algorithms that mimic aware behavior, which leaves open to interpretation whether it will pave the road to machine consciousness or simply build a better parrot.

The third question has inspired new studies that coax consciousness into the open, discovering that some heightened forms of awareness continue after the mind falls asleep, while more rudimentary kinds of awareness can even enter the mind through a temporarily blinded eye.

At the latest Toward a Science of Consciousness conference, which ended in Tucson on Friday, Brooks reported on his lab's latest efforts to teach its robot, named Kismet, some basic protocols of aware behavior.

First, he said, came the task of finding every set of human eyes in its field of view, so Kismet could follow the primary human medium for sending cues. This was done by detecting any oval-shaped objects with human skin tones and using geometrical models of faces to isolate that face's windows on the world.

From there, motion-detecting software -- combined with knowledge of the laws of classical physics -- allowed Kismet to sense when an object was ballistic and when it was guided by a conscious hand.

Algorithms such as these allowed the robot to perform basic interactions, such as simulating short conversations with humans and following a pointing hand toward the object it points at -- a task that cat and dog owners know nature's programmers never quite debugged for some species.

"Unlike neuroscience, where scientists are presented with an existing object they have to study, we get to build these objects and understand what we put into them," Brooks said.

Pure awareness, stripped of any corresponding mental state, does present itself for study in humans, said Fred Travis of the Maharishi University of Management. Travis reported on his recent efforts to isolate patterns of brain activity in subjects who regularly practice transcendental meditation.

"Can there be a sense of self without mental content, which is just aware of its own structure without perception or thinking?" he asked.

This state of consciousness in experienced meditators was characterized by EEG data that Travis presented, which showed brain patterns of wakeful awareness (so-called theta and alpha activity) that appeared even when the subjects were in deep sleep.

These findings were also consistent with meditators' claims.

"Subjects report a permanent integration of transcendental experiences with waking, sleeping and dreaming," Travis said.

Basic forms of awareness can be studied in the absence of conscious awareness, said Randolph Blake of Vanderbilt University. He presented a series of results involving subjects who were shown different images in each eye.

The brain, when presented with an image from the left eye that's completely different from the image in the right eye, cycles its conscious attention between eyes. Thus, at a moment when one eye is dominant, the images appearing before the other eye lie outside a subject's visual consciousness.

This laboratory trick -- called "binocular rivalry" -- allows researchers to provoke mental responses to changing images in one eye, even though the mind may be focused on the input coming from the other.

For instance, Blake summarized the results of a study in which subjects watched a rotating pinwheel pattern and then trained their sight on a still image that appeared to move. This optical illusion, his lab found, could even be provoked when the spinning pinwheel was only observed by the unconscious eye.

Subsequent studies, including brain-imaging studies, indicate that the brain's more basic regions for visual processing (including the primary visual cortex) handle these images, even though the pinwheels are suppressed from a person's awareness.

Yet when the researchers presented the subjects' temporarily "blinded" eye with images that required advanced visual or verbal processing -- requiring more sophisticated tasks beyond the range of the visual cortex -- they could not provoke unconscious awareness.

Blake said that binocular rivalry is a useful tool for probing some of the rudiments of awareness, but the "knife is not sharp enough" to slice into the root cause of awareness. To that end, he cited the early 20th century psychologist William James.

"We know what consciousness is," James famously wrote, "as long as no one asks us to define it."


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