Missing Shades of Grue

For example, if the 'Jennifer Anniston neuron' increases its firing then we can predict that the subject is seeing Jennifer Aniston. If the 'Halle Berry neuron' fires, then we can predict that the subject is seeing Halle Berry, and so on. To do this, we used and optimised a 'decoding algorithms', which is a mathematical method to infer the stimulus from the neuronal firing. We also needed to optimise our recording and data processing tools to record simultaneously from as many neurons as possible. Currently we are able to record simultaneously from up to 100 neurons in the human brain.

If I were to be eaten by a shark, I'm pretty sure the worst part would be not the pain or the mutilation or the actual dying and so forth, but rather the thought balloon over my head with the words, "I'm being eaten by a [expletive] shark!"

In a letter published this year in the journal Science, 10 scientists said that a Decade of the Mind would help us understand mental disorders that affect 50 million Americans and cost more than $400 billion a year. It might also aid in the development of intelligent machines and new computing techniques. A breakthrough in mind research, the scientists wrote, could have "broad and dramatic impacts on the economy, national security and our social well-being."

Cracking the code of the mind may be ultimately impossible. My guess is that a century from now, scientists and philosophers will still be arguing about the what, where and how of it all.

But we should still take a whack at it. Ten years and $4 billion: That's a reasonable cost. The evolution of the human mind is arguably the most important biological event in the history of our planet since the origin of life itself.

We should try to understand how the brain makes the mind. And then we can make up our minds about what to do with ourselves.

A woman with an artificial arm has been given the sense of touch following a pioneering operation to reroute some of her nerves. Claudia Mitchell, 27, lost her left arm in a motorcycle accident three years ago, but can now feel her missing hand after having nerves from her lost limb rerouted to her chest. [emphasis mine]

Now, when she touches something with her artificial hand she can feel it through a device attached to her chest.

During a four-hour operation, surgeons moved nerves from her shoulder, which normally ferry signals from the hand to the brain, and redirected them to muscles in her chest area.

I suggest that a new set of brain structures evolved during hominid evolution, turning the output from more primitive sensory areas of the brain into what I call a "metarepresentation." I think they edited, enhanced and packaged sensory information into more manageable chunks, used for juggling symbols and language. And most important, they made the link to meaning--whereby the sensory objects we perceive evoke multiple parallel implications in our minds. For example, an apple has potentially infinite nuances of meaning for humans, such as baking, keeping the doctor away, tempting Eve. But for a lemur, apple has no "meaning"; it's simply identifiable as food.

I believe the anatomical structures involved in creating this metarepresentation include the inferior parietal lobule, Wernicke's language comprehension area and the anterior cingulate cortex. Find out how these structures perform their job and we will have figured out what it means to be a conscious human being.

It seems to me Humphrey makes a fundamental error from the beginning. He thinks that the solution to our problem has to be in the form of an equation, mind = brain, rather than in a causal account. Why should we make this assumption? There are lots of explanations in science and philosophy that are not in the form of equations. In fact, equations are rather rare in biology. Think of the germ theory of disease or the theory of evolution. What we are interested in, in these cases, are causal mechanisms, not equations. What causes disease symptoms? What is the causal account of the evolution of human and animal species from simpler forms of life? And now, what causes consciousness?

Researchers at Harvard University and University College London have developed diagnostic tests for prosopagnosia, a socially disabling inability to recognize or distinguish faces. They've already used the new test and a related web site (www.faceblind.org) to identify hundreds of "face-blind" individuals, far more than scientists had identified previously.

The researchers, led by Ken Nakayama and Richard Russell at Harvard and Bradley Duchaine at University College London, have found evidence that prosopagnosia, once thought to be exceedingly rare, may affect up to 2 percent of the population -- suggesting that millions of people may be face-blind.

...2% is just way too high for something that seems so clearly maladaptive. This is only a few steps short of finding out that 2% of the population was incapable of language, recognizing faces is a necessary precondition for much of human sociality.

The problem then is how to explain consciousness, and everybody agrees this is a very difficult topic. And the question is: can it be explained by neuroscience?

The term "theory of mind" refers to the fundamental ability of a person to understand that other people can have intentions or desires that are different. But does the concept hold for other species? Can a chimpanzee, say, know what another chimpanzee is intending?

The issue is a subject of much debate, and a new study by Thomas Bugnyar and Bernd Heinrich of the University of Vermont is sure to add to the discussion. In a study in Proceedings B of the Royal Society, the two show that ravens know what other ravens have or have not seen.

Ravens store caches of food, which are often pilfered by other ravens who watch while the food is being hidden. In one set of experiments, the researchers allowed a raven that was storing food to see whether another was watching (in this case the second bird was visible to the first but was shielded from the cache by a curtain).

Later, the two ravens were set loose to retrieve the cache. The bird that stored the food behaved differently based on whether the other bird had watched earlier.

A second set of experiments involved two pilfering birds. The researchers found that when retrieving food, a bird that watched the food being cached acted differently if the other bird had watched, too.

Taken together, the researchers say, the results show that ravens are capable of identifying other birds and of knowing what the others had or had not seen. They add that the findings are in line with other work on ravens and crows that shows they have great cognitive potential when it comes to social behavior.