November 25, 2013
Decision Making Linked To One Of The Brain’s Oldest, Smallest Regions
[ Watch the Video: Tiny Brain Region Linked To Decision Making ]
redOrbit Staff & Wire Reports - Your Universe Online
The lateral habenula, which is believed to be one of the oldest parts of the brain in evolutionary terms and has previously been linked to depression and avoidance behaviors, also plays a key role in decision making, researchers from the University of British Columbia report in the study. This region of the brain has been largely misunderstood and could be integral in the cost-benefit decision-making process, they added.
“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,” explained Stan Floresco, a behavioral neuroscience professor at the university’s Department of Psychology and Brain Research Centre (BRC). “It also suggests that the scientific community has misunderstood the true functioning of this mysterious, but important, region of the brain.”
As part of the research, Floresco and his colleagues trained laboratory rats to choose between a consistently small reward (a single food pellet) or a larger reward (four food pellets) which only appeared sporadically. Like people, the rodents typically selected the larger reward when the costs (the amount of time they needed to wait before receiving their reward) were low, and tended to opt for the smaller reward when the 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,” the university said in a statement, adding that the findings could have “important implications” when it comes to treating depression in humans.
“Deep brain stimulation – which is thought to inactivate the lateral habenula – has been reported to improve depressive symptoms in humans,” said Floresco, who worked on the study with doctoral candidate Colin Stopper. “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.”
However, Floresco emphasizes that more research is required in order to fully understand the complete brain functions involved in cost-benefit decision processes and related behavior. Furthermore, they said that a better understanding of the decision-making process is also essential, since depression and many other psychiatric disorders have been linked to impairments in these processes.