10 October 2008

What the Mind Knows, What It Thinks It Knows That Just Isn't So, And What May Yet Grow

Everything we know, everything we believe, everything we think and understand, comes from the function of our brains. A better understanding of brain function is opening a clearer window into how our brains create the worlds we inhabit.

Recently, researchers from St. Louis and Boca Raton, Florida have applied "Granger Causality" to fMRI studies in an attempt to more precisely trace the flow of information between brain centers, in the performance of a mental task. Sir Clive Granger was a co-recipient of the 2003 Nobel Prize in Economics for his method of comparing complex time series of economic data, to forecast economic changes. The researchers used Granger causality to overcome the poor time resolution (roughly 2 seconds) in the fMRI data in analysing information flow in the brain.
Chad Sylvester, an M.D./Ph.D. student at Washington University, gathered the data for the analysis. Researchers gave volunteers a cue that a visual stimulus would be appearing soon in a portion of a computer display screen, and asked them to report when the stimulus appeared and what they saw. Corbetta's group previously revealed that this task activated two brain areas: the frontoparietal cortex, which is involved in the direction of the attention, and the visual cortex, which became more active in the area where volunteers were cued to expect the stimulus to appear.

Scientists believed the frontoparietal cortex was influencing the visual cortex, but the brain scanning approach they were using, functional magnetic resonance imaging (fMRI), can only complete scans about once every two seconds, which was much too slow to catch that influence in action. When researchers applied Granger causality, though, they were able to show conclusively that as volunteers waited for the stimulus to appear, the frontoparietal cortex was influencing the visual cortex, not the reverse. _Source
The complex timing and sequencing involved in neural signaling between brain centers, has been a particularly difficult problem in understanding how the brain generates consciousness and knowledge. It is also a difficult challenge to AI researchers who are trying to simulate animal consciousness via artificial cortex architectures.

Chris Chatham's blog Developing Intelligence regularly looks at some of these neuro-cognitive research teasers. One of the most interesting topics Chris examines is the topic of "far transfer":cognitive training for one skill that also creates competence in other areas.
What if training ourselves on one task yielded improvements in all other tasks we perform? This is the promise of the cognitive training movement, which is increasingly showing that such "far transfer" of training is indeed possible, while short of being "universal transfer." Interestingly, this phenomenon might be most likely to occur for some of the most abstract and challenging cognitive functions. _DevelIntel
In general, acquiring expertise in a narrow specialty does not result in broader competence. People often exaggerate their own competence in multiple areas, based upon expertise in a specialised field. If they are lucky, their misplaced hubris results only in their making fools of themselves, rather than losing their fortunes, families, and sanity.

In fact, all human minds have their blind spots, their areas of false certainty.
LEHRER: In your book, you compare the "feeling of certainty" that accompanies things such as religious fundamentalism to the feeling that occurs when we have a word on the-tip-of-our-tongue. Could you explain?

BURTON: There are two separate aspects of a thought, namely the actual thought, and an independent involuntary assessment of the accuracy of that thought.

To get a feeling for this separation, look at the Muller-Lyer optical illusion.

Even when we consciously know and can accurately determine that these two horizontal lines are the same length, we experience the simultaneous disquieting sensation that this thought—the lines are of equal length—is not correct. This isn't a feeling that we can easily overcome through logic and reason; it simply happens to us.

This sensation is a manifestation of a separate category of mental activity—-unconscious calculations as to the accuracy of any given thought. On the positive side, such feelings can vary from a modest sense of being right, such as understanding that Christmas falls on December 25, to a profound a-ha, "Eureka" or sense of a spiritual epiphany. William James referred to the latter—the mystical experience—as "felt knowledge," a mental sensation that isn't a thought, but feels like a thought.

Once we realize that the brain has very powerful inbuilt involuntary mechanisms for assessing unconscious cognitive activity, it is easy to see how it can send into consciousness a message that we know something that we can't presently recall—the modest tip-of-the-tongue feeling. At the other end of the spectrum would be the profound "feeling of knowing" that accompanies unconsciously held beliefs—a major component of the unshakeable attachment to fundamentalist beliefs—both religious and otherwise—such as belief in UFOs or false memories.

LEHRER: Why do you think that the feeling of certainty feels so good?

BURTON: Stick brain electrodes in rat pleasure centers (the mesolimbic dopamine system primarily located in the upper brain stem). The rats continuously press the bar, to the exclusion of food and water, until they drop. In humans the same areas are activated with cocaine, amphetamines, alcohol, nicotine and gambling—to mention just a few behaviors to which one can become easily addicted.

It is quite likely that the same reward system provides the positive feedback necessary for us to learn and to continue wanting to learn. The pleasure of a thought is what propels us forward; imagine trying to write a novel or engage in a long-term scientific experiment without getting such rewards. Fortunately, the brain has provided us with a wide variety of subjective feelings of reward ranging from hunches, gut feelings, intuitions, suspicions that we are on the right track to a profound sense of certainty and utter conviction. And yes, these feelings are qualitatively as powerful as those involved in sex and gambling. One need only look at the self-satisfied smugness of a "know it all" to suspect that the feeling of certainty can approach the power of addiction. _SciAm
It feels good to be right. Of course, one is often wrong at the same time he feels himself right. It still feels good. Hence the attraction of violent jihad, lynch mobs, programming by college professors, witch hunts, cult indoctrination, and political rallies. Resonating with the emotions of the crowd only magnifies the sensation of "rightness."

As America contemplates electing its own "Dear Leader", it is good to keep in mind how fallible our mental world's creation truly is. If a politician makes you feel that he will make everything right, you have certainly been taken in by a skilled practitioner of world creation. Run away. Quickly.


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“During times of universal deceit, telling the truth becomes a revolutionary act” _George Orwell

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