A new study identifies a small area of the brain that appears to be important for decision-making and depression treatment.
University of British Columbia researchers believe the lateral habenula, a region of the brain linked to depression and avoidance behaviors, has been largely misunderstood and may be integral in cost-benefit decisions.
“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 researcher Stan Floresco, Ph.D.
“It also suggests that the scientific community has misunderstood the true functioning of this mysterious, but important, region of the brain.”
In the study, scientists trained lab rats to choose between a consistent small reward (one food pellet) or a potentially larger reward (four food pellets) that appeared sporadically.
Like humans, the rats tended to choose larger rewards when costs — in this case, the amount of time they had to wait before receiving food — were low and preferred smaller rewards when such risks were higher.
Previous studies suggest that turning off the lateral habenula would cause rats to choose the larger, riskier reward more often, but that was not the case.
Instead, the rats selected either option at random, no longer showing the ability to choose the best option for them.
Researchers believe the findings may have important implications for depression treatment, especially deep brain stimulation (DBS). DBS is often utilized when conventional forms of depression treatment have been unsuccessful.
“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.”
Source: University of British Columbia