April 23, 2006
Scientists Find Brain Cells Linked to Choice
LONDON -- If choosing the right outfit or whether to invest in stocks or bonds is difficult, it may not be just indecisiveness but how brain cells assign values to different items, scientists said on Sunday.
Researchers at Harvard Medical School in Boston have identified neurons, or brain cells, that seem to play a role in how a person selects different items or goods.Scientists have known that cells in different parts of the brain react to attributes such as color, taste or quantity. Dr Camillo Padaoa-Schioppa and John Assad, an associate professor of neurobiology, found neurons involved in assigning values that help people to make choices.
"The neurons we have identified encode the value individuals assign to the available items when they make choices based on subjective preferences, a behavior called economic choice," Padoa-Schioppa said in a statement.
The scientists, who reported the findings in the journal Nature, located the neurons in an area of the brain known as the orbitofrontal cortex (OFC) while studying macaque monkeys which had to choose between different flavors and quantities of juices.
They correlated the animals' choices with the activity of neurons in the OFC with the valued assigned to the different types of juices. Some neurons would be highly active when the monkeys selected three drops of grape juice, for example, or 10 drops of apple juice.
Other neurons encoded the value of only the orange juice or grape juice.
"The monkey's choice may be based on the activity of these neurons," said Padoa-Schioppa.
Earlier research involving the OFC showed that lesions in the area seem to have an association with eating disorders, compulsive gambling and unusual social behavior.
The new findings show an association between the activity of the OFC and the mental valuation process underlying choice behavior, according to the scientists.
"A concrete possibility is that various choice deficits may result from an impaired or dysfunctional activity of this population (of neurons), though this hypothesis remains to be tested," Padoa-Schioppa.