Attempting to achieve more than one goal at once—be it losing weight, studying for exams, quitting smoking, or hitting the gym—may not be a good idea. These tasks require self-control, an essential but limited resource.
A new study led by Dr. Michael Inzlicht, an assistant professor of psychology at the University of Toronto Scarborough, explores how exercising self-control for too long depletes the brain. Forty students from the Scarborough campus were divided into two groups and asked to perform two unrelated tasks involving self-control. For the first task, both groups were shown the same two movie clips depicting animals in distress or close to death. One group was asked to suppress their emotions while the other group was instructed only to watch the clips.
Shortly following the movie, the participants were asked to perform the ‘Stroop task’: the words red and green were displayed in either red or green font. Participants were told to identify the font colour, not to read the word itself. For both tasks, all participants wore an electrode cap to record their brain activity (EEG or electroencephalographic recording).
The study found that participants who suppressed their emotions during the first task performed poorly during the second task. Additionally, this poor performance corresponded to decreased brain activity in the cingular cortex, the part of the brain that monitors a person’s intention to achieve a goal.
Inzlicht explained, “If you have already used self-control in a previous task, then the cingular cortex gets tired. For example, if you then try to eat a french fry it won’t tell you not to.” Inzlicht continued, “When you work out a muscle it becomes tired. It will be tired and you won’t be able to function as you did beforehand.” When the cortex is worn-out, it cannot function as usual, depleting a person’s self-control over, for example, eating that french fry.
Inzlicht offered a take-home message for students. “If you’re studying for an exam (for example) and you’re a smoker, it wouldn’t be the best idea for you to try to quit smoking during exam period. It is difficult to stop smoking because it requires a level of self-control, as does studying. Self-control is limited, so when we use self-control to stop smoking it will be hard to study for our exams.”
His research study, entitled “Running on Empty: Neural Signals for Self-Control Failure” appeared in the November 2007 issue of Psychological Science.
The study expands on previous knowledge that self-control is a limited and essential resource. Experiments similar to the one preformed by Inzlicht determined that tasks requiring intentional and controlled actions exhaust this central resource. But it was not known what brain processes were involved or that the cingular cortex is always active and, therefore, gets tired.
Further research may look into the psychological level of self-control. For example, a person who manages to achieve their goals is likely to possess intrinsic motivation. Or, it may look more closely at the cingular cortex of the brain with respect to dopamine. It has been previously determined that the cortex is responsive to this chemical, a hormone that is often associated with feelings of enjoyment and motivation.
Pay attention to the things that matter and don’t waste that limited self-control on pointless goals. Maybe quitting smoking would be a good start—but wait until January, perhaps.
