New Paper Pinpoints a Seat of Self-Control in the Brain

Led by Bernd Figner, a research scientist at Columbia University's Department of Psychology, and Elke Weber, a founding director of the Center for Decision Sciences at Columbia Business School, the team used a non-invasive brain-stimulation technique (called transcranial magnetic stimulation, or TMS) to temporarily disrupt the function of the lateral prefrontal cortex in a group of volunteers.

Out of 52 healthy subjects, one-third received stimulation to the left prefrontal cortex; one third to the right prefrontal cortex; and one third, the control group, received sham stimulation. After the stimulation, the volunteers were asked to make choices between smaller, immediate rewards or larger, later rewards.

"When we disrupted the function of the left prefrontal cortex, we found that people more often chose the tempting immediate rewards," says Figner.

Significance

"There's a very important general need to understand the ability to delay gratification in these kinds of decisions," says Figner. "This ability has been implicated not only in many decisions that we all face every day but also in psychiatric disorders related to impulse control such as substance abuse. Also, when we look at development in children and adolescents, these age groups also have a hard time delaying gratification. In these age groups, the lateral prefrontal cortex is not yet fully developed. This is another piece of the puzzle as to why these younger age groups have a harder time delaying gratification."