“We asked volunteers to make choices involving different levels of monetary reward and physical effort, while they were placed in a MRI scanner,” researcher Dr Miriam Klein-Flügge told Oxford University about the new research.
“We found that the decisions they made were influenced by both reward size and effort required, with — unsurprisingly — higher reward, lower effort options being particularly favored. We then looked for particular brain regions involved in the decision-making,” she explained.
The scans revealed that decision-making seemed to produce activity in three areas of the brain: the supplementary motor area (SMA), dorsal anterior cingulate cortex (dACC) and putamen.
Previous research has supported the theory that there is not one single decision-making system in the brain, according to Klein-Flügge. The new study also backs the thought that, instead, the mind combines a set of process, which vary depending on the decision.
“There are many situations that require us to weigh up effort and reward, for instance deciding whether the extra long walk to get our favorite type of sandwich is worth more than a shorter walk for a less favored sandwich,” said Dr Raliza Stoyanova of the Neuroscience and Mental Health team at the Wellcome Trust and European Research Council — which supported the study.
“Although we know a lot about how the brain reacts to rewards of different sizes, the current study is the first to shed light on a brain region that is involved in comparing the size of a reward and the physical effort required to get it. Given that a range of psychiatric conditions involve difficulties in reaching rewards when they require effort, these results open up a number of avenues for future research to test more precisely if, and how, the reward/effort balance may go awry,” Dr Stoyanova told Oxford University.
The study may lead to insights about depression and other conditions that involve a patient’s difficulty in making decisions or exerting effort.
Source: Klein-Flugge MC, Kennerley SW, Friston K, Bestmann S. Neural Signatures Of Value Comparison In Human Cingulate Cortex During Decisions Requiring An Effort-Reward Trade-off. Journal of Neuroscience. 2016.