Nov. 25 (UPI) -- A University of British Columbia study suggests that a small part of the brain called lateral habenula plays a crucial role in decision making.
The region, which has been associated with depression and avoidance behaviors, is also where the brain makes its cost-benefit analyses.
The study tested the decision made by mice to choose a small reward, one food pellet, or a big reward, four food pellets. Like humans, the rats chose the bigger rewards when the risks of such a decision, like reduced time between food pellets appearing, was low and preferred a single pellet when the risks were higher.
“These findings clarify the brain processes involved in the important decisions that we make on a daily basis, from choosing between job offers to deciding which house or car to buy,” said Prof. Stan Floresco in a statement. “It also suggests that the scientific community has misunderstood the true functioning of this mysterious, but important, region of the brain.”
Previous studies have suggested that turning off the lateral habenula would lead the rats to choose the bigger reward and take bigger risks. On the contrary, the rats started choosing rewards at random with no regard to the risk involved.
"Deep brain stimulation -- which is thought to inactivate the lateral habenula -- has been reported to improve depressive symptoms in humans,” Floresco says. “But our findings suggest these improvements may not be because patients feel happier. They may simply no longer care as much about what is making them feel depressed.”
