Left yes, right no

Left yes, right no

Positive and negative parts of the brain.

"Like the Chinese philosophy of yin and yang, the study of the human brain has developed around opposites: right and left, negative and positive, pleasant and unpleasant.

Research from the University of Wisconsin's Laboratory for Affective Neuroscience in Madison identifies the left prefrontal cortex (the outer, gray matter) as the area of the brain associated with positive or pleasant sensations and the right side of the brain as the area associated with negative or unpleasant experiences.

The conclusions are based on a study of 72 heavy smokers who were asked not to smoke for a full day. Then, with their brains wired to special scanning equipment, they were told they could smoke again in two minutes. The left prefrontal cortex lit up dramatically in anticipation of a pleasurable experience, reports the Washington Post.

In a related test, the brains of 14 infants were wired and scanned when the babies were separated from their mothers. Some babies cried and some began exploring their environment. The right prefrontal cortex was highly active in babies who cried, while the left was active in the explorers, the article reports."