Wednesday, June 21, 2006

newness junkies & knowledge addiction, mechanism found

I've jokingly said in the past that I'm a "newness junkie", which is partly my motivation for the years of finding new facinating things for this web site. I also really love learning. This may be why:
"Neuroscientists have proposed a simple explanation for the pleasure of grasping a new concept: The brain is getting its fix.

The "click" of comprehension triggers a biochemical cascade that rewards the brain with a shot of natural opium-like substances, said Irving Biederman of the University of Southern California. ...
Biederman also found that repeated viewing of an attractive image lessened both the rating of pleasure and the activity in the opioid-rich areas. In his article, he explains this familiar experience with a neural-network model termed "competitive learning."

newness.jpgIn competitive learning (also known as "Neural Darwinism"), the first presentation of an image activates many neurons, some strongly and a greater number only weakly.

With repetition of the image, the connections to the strongly activated neurons grow in strength. But the strongly activated neurons inhibit their weakly activated neighbors, causing a net reduction in activity. This reduction in activity, Biederman's research shows, parallels the decline in the pleasure felt during repeated viewing. "One advantage of competitive learning is that the inhibited neurons are now free to code for other stimulus patterns," Biederman writes. This preference for novel concepts also has evolutionary value, he added.

"The system is essentially designed to maximize the rate at which you acquire new but interpretable [understandable] information. Once you have acquired the information, you best spend your time learning something else.

"There's this incredible selectivity that we show in real time. Without thinking about it, we pick out experiences that are richly interpretable but novel." The theory, while currently tested only in the visual system, likely applies to other senses, Biederman said." - more

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