The way our brains handle the neurotransmitter dopamine can help determine how motivated (or unmotivated) we are, according to new research. In other words, the difference between slackers and overachievers could be explained by their relationships to this crazy brain chemical. And this discovery could lead to new treatments for increasing motivation.
The study, published in the May issue of The Journal of Neuroscience, shows for the first time that increased dopamine activity in a part of the brain called the insula can make people less willing to work.
Dopamine activity affects many things—movement, memory, learning, mood, sleep—but it’s especially important for “reward processing,” or the way your brain reacts to things such as drugs, food, sex and power. These rewards trigger increased dopamine activity in the brain; stimulants like cocaine, meth work directly on the dopamine system. Decreased dopamine activity has been linked to depression, Parkinson’s disease and ADHD.
It seems decreased dopamine activity would also be associated with decreased motivation, but not so. In the study, subjects were given a series of tests (things like pressing a button a certain number of times in a minute) in which they could earn small monetary rewards.
Some accepted harder challenges for more money even against long odds, whereas less motivated subjects would forgo an attempt if it cost them too much effort.
After this, participants underwent brain imaging to measure dopamine activity in different parts of the brain. Both high and low motivation were associated with increased dopamine activity. The difference was in where this activity took place: Those willing to work harder showed more dopamine response in parts of the brain known as the striatum and the ventromedial prefontal cortex; those who expended the least effort showed increased dopamine in the insula region.
The fact that dopamine can have opposing effects in different parts of the brain complicates the use of psychotropic meds that affect dopamine levels, researchers note. But knowing this could lead to better drugs for treating ADHD, depression and other mental issues that kill motivation.