Scholaris Erratus

How the Slacker Brain Conserves Energy

I heard this piece on NPR the other morning describing an experiment in which people asked to memorize numbers of varying lengths (some memorized two numbers; others memorized seven) were offered the choice of a snack on the way to recite the numbers.  One snack was healthy, and the other was not.  The study found that those whose brains were consuming energy in trying to memorize the longer number were unable to resist the temptation of the unhealthy choice of snack, whereas those who weren’t burning as much mental energy in memorizing only two numbers did resist the temptation.

It turns out, Jonah explains, that the part of our brain that is most reasonable, rational and do-the-right-thing is easily toppled by the pull of raw sensual appetite, the lure of sweet. Knowing something is the right thing to do takes work — brain work — and our brains aren’t always up to that. The experiment, after all, tells us brains can’t even hold more than seven numbers at a time. Add five extra digits, and good sense tiptoes out of your head, and in comes the cake.

The concept of “psychoenergonomics” (of managing mental energy) offers insight into what is happening here:  because the energy in their brains was directed toward the rational part of the mind, it wasn’t in the part of the brain that helps with resisting such temptations.

30 January 2010 at 5:19 am 1 comment