The joyful mind.

n the 1950s psychiatrist robert heath of tulane university launched a controversial program to surgically implant electrodes into the brains of patients institutionalized with epilepsy, schizophrenia, depression and other severe neurological conditions. His initial objective: to locate the biological seat of these disorders and, by artificially stimulating those regions, perhaps cure individuals of their disease. A new understanding of how the brain generates pleasure could lead to better treatment of addiction and depression—and even to a new science of happiness