Lateral habenula, the smallest part of the brain plays an important role in decision making, University of British Columbia researchers find.
Lateral habenula, the smallest part of the brain has always been associated with negative attributions like depression and avoidance behaviors. However, researchers from the University of British Columbia are giving this brain region a second look after finding that it plays an important role in decision making, according to a press release.
For the study, Prof. Stan Floresco of UBC's Dept. of Psychology and Brain Research Centre trained laboratory rats to choose between consistent small rewards or a potentially larger reward that appeared sporadically. Researchers observed that like humans, rats too opted for larger rewards when the waiting period was short but smaller rewards when the waiting period was longer.
"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. "It also suggests that the scientific community has misunderstood the true functioning of this mysterious, but important, region of the brain."
A similar study conducted in the past found that turning off the lateral habenula would cause rats to choose the larger, riskier reward more often.The new study found that when this region of the brain was turned off, the rats selected either option at random, no longer showing the ability to choose the best option for them.
The findings have important implications for depression treatment.
"Deep brain stimulation - which is thought to inactivate the lateral habenula -- has been reported to improve depressive symptoms in humans," Floresco said. "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."
