The Biology of Joy

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Deciphering the code of art into the language of modern science took most of two centuries. One discipline after another tried to define what feelings like pleasure were, and from where they arose, only to fall short. Darwin could sense that emotions were important in his evolutionary scheme of things, but he was limited to describing how animals and humans expressed them on the outside, using their bodies, especially faces. William James, in a famous theory published in 1884, speculated that the brain only translates various sensations originating below the neck into what we think of as, say, joy and fear. Others saw it the other way around-- emotions begin in the brain and the bodily reactions follow. Without knowing what pleasure actually is, Freud could see that the inability to feel it is a kind of disease, or at least a symptom, that he traced to (you guessed it) neurotic conflict.

By then, though, many people were fed up with all the talking. The study of mind had reached that point in the movie where the gung-ho types shove aside the hostage negotiator and shout, "We're going in." And with scalpels drawn, they did. In 1872, Camillo Golgi, a young doctor working at a "home for incurables" in an Italian village, discovered the basic component of brain tissue, the neuron. It's best not even to ponder how he got his samples. During the 1920s, German scientist Otto Loewi, working with frog hearts, first identified neurotransmitters: chemical messengers that carry information across the gap between the neurons--the synapse--to receptors on the other side. In the 1940s, the Canadian neurosurgeon Wilder Penfield, operating on conscious patients with severe epilepsy, managed to trigger various emotions and dreamlike memories by electrically stimulating their brains. Such work gave rise to the idea that various mental functions might be "localized" in particular brain areas.

In 1953, psychologists James Olds and Peter Milner made a remarkable breakthrough--by accident. While researching the alerting mechanism in rat brains, they inadvertently placed an electrode in what they soon identified as a rat's pleasure-and-reward center: the so-called limbic system deep inside the brain. When the rats were later wired in a way that let them press a lever and jolt themselves, they did so as many as 5,000 times an hour. It was like watching a keyboard player, demented by joy, pounding out the same frenetic arpeggio of pleasure over and over and then collapsing. Philip Glass, take heed.

This became the basis for current research on the "biology of reward." Scientists like Kenneth Blum have linked what they call reward deficiency syndrome to various human behavioral disorders: alcoholism, drug abuse, smoking, compulsive eating, gambling. Blum traces these disorders to genetically derived flaws in the neurotransmitters and receptors now associated with pleasure, including the pathways tied to the brain chemicals serotonin and dopamine, and the endorphins. Other researchers aren't so sure.

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