How your brain helps you make up your mind

Washington – Researchers have claimed that the lateral habenula – one of the oldest regions of the brain, evolution-wise – a region of the brain linked to depression and avoidance behaviors, has been largely misunderstood and may be integral in cost-benefit decisions.

Prof. Stan Floresco of UBC’s Dept. of Psychology and Brain Research Centre (BRC), said that 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.

He said that 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.

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 says.

Floresco said that their findings suggest these improvements may not be because patients feel happier, added that they may simply no longer care as much about what is making them feel depressed.

The study has been published in journal Nature Neuroscience.