What Happens In The Brain As We Choose Between Effort And Indulgence?

An insightful piece by Jonah Lehrer on some recent research covering what happens in the brain when we choose between effort and indulgence. Lehrer argues that individual differences make it slightly easier for some people to engage in hard effort. “These diligent souls,” he writes, “seem to get a bit more pleasure from the possibility of reward, but they also seem less sensitive to their inner complainer, that disruptive voice reminding them that minesweeper is more fun than editing, or that the ballgame on television is much more entertaining than their homework.”

The experiment utilized a simple protocol. Twenty five subjects were asked to choose between an easy or hard task that involved pushing a button. (Sounds fun, right?) Easy tasks earned $1 while the payout for hard tasks ranged from $1 to $4.30. After selecting their degree of difficulty, subjects were told that their reward was not guaranteed, and that they actually had a low (12%), medium (50%) or high (88%) chance of getting paid. The tasks themselves lasted for 30 seconds and were mind-numbingly tedious: subjects were asked to either press a button with their dominant hand 30 times in seven seconds (easy condition) or 100 times in twenty-one seconds with their non-dominant pinky finger. Such a chore makes writing look like a day at the beach.

While the bored students were frantically pressing buttons, the scientists were monitoring changes in their brain using a modified PET scan able to track the activity of dopamine neurons throughout the cortex. This allowed the scientists to search for correlations between dopaminergic activity and the willingness of subjects to pursue the least pleasurable forms of labor. They could see why some people stopped pressing the buttons while others persisted, even after their pinky began to ache.

The first thing Treadway and colleagues discovered is that subjects showing greater dopaminergic activity in the left striatum and ventromedial prefrontal cortex were more willing to work hard in exchange for greater rewards. These differences were especially striking when the probability of a payout was low. Although the odds are actually getting the money were minuscule, these subjects found a way to stay motivated. This result isn’t too surprising, since several other brain scanning studies have linked these regions to cost-benefit analysis, as the brain automatically calculates whether or not a certain alternative (say, pressing a button 100 times for cash) is worth the expense, which in this case is effort. Although we’re not consciously aware of these calculations, they determine whether we finish this sentence or go play Angry Birds.

But that’s not the only interesting correlation uncovered by the PET scans. The scientists also discovered a surprising inverse relationship between dopamine activity in the insula and the willingness to exert effort.

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Still curious? Jonah Lehrer is the author of the controversial new book Imagine: How Creativity Works.