Temptation

Temptation
Baffling, cunning and confusing addictive thinking ruins lives.

Sunday, October 30, 2011

Positive Addiction?

Addicted to Exercise?
By NICHOLAS D. KRISTOF


FOR decades, scientists have studied areas deep within the brain that seem associated with pleasure and addiction.

Put an electrode in that part of a rat’s brain, and it will become obsessed with stimulating those areas. When rats are allowed to push a lever in exchange for a mild current that produces a “high” in the “pleasure centers,” they will press the lever up to 7,000 times per hour.

These rats forget to eat or drink, and they must be unhooked to prevent self-starvation. Male rats ignore females in heat to get a fix, and nursing mothers ignore their babies.

“Pressing that lever became their entire world,” David J. Linden, a neuroscientist at Johns Hopkins University medical school, writes in his fascinating new book, “The Compass of Pleasure.”

Professor Linden explains how drugs such as cocaine that light up these pleasure centers (there are several interconnected areas) actually rewire the brain to increase cravings.

Exercise seems to trigger the release of chemicals called endorphins and enkephalins (the brain’s version of opium) and endocannabinoids (the brain’s version of marijuana). In the lab, rats can develop an addiction to exercise on a wheel.

Linden argues that there is such a thing as a genuine biological addiction to sex. The public’s failure to recognize this, he says, means that people often don’t receive treatment.

Brain chemistry research also suggests that gambling and overeating can be addictive behaviors, analogous to narcotics addictions. In particular, foods with sugar or fat seem to trigger cravings that then rewire the brain’s pleasure circuitry to amplify that craving.

One study found that rats fed foods like cheesecake and chocolate showed differences in brain circuitry after just 40 days. The impact was that the pleasure centers of their brains were numbed, so they apparently needed to gobble even more cheesecake to generate the same satisfaction. Whether it’s sugar or heroin, the body steadily ratchets up the quantity necessary to provide the same high.

Moreover, our brains impel us not only toward vices, but also toward virtues.

On the basis of the latest brain research, acknowledge this profound truth: altruism and generosity can be hedonistic pleasures.


Source:
Addicted to Exercise? - NYTimes.com:


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