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Exerting self control with a reluctant prefrontal cortex

Mar 20, 2016

When I was younger, I was late more often than not.   During the week before graduating college, my research advisor invited students who had worked in his lab to a barbecue at his house. After we ate he handed us little graduation gifts. Mine was a Mickey Mouse watch to remind me what time it is. I felt bad that he had come to see my lateness as one of my salient characteristics. It's not that he was an uptight guy either.  He was laid-back, with a dog named Pavlov that would roam the hall outside his office. The next year, when I went to grad school at UC, Santa Barbara, I was determined that this would not be the way my new advisor viewed me. (It wasn't.)

In order to be on time, you need to recruit the prefrontal cortex, a brain area that thinks about events in a logical sequential way.  One of the reasons that dreams sometimes involve impossible sequences of events is that the prefrontal cortex is off-line.

But being on time requires something more than knowing what steps you need to take before you leave and how long they will take; it requires self discipline. To be on time we need to stop doing what we're doing at the moment, even if we're enjoying it, and get ready to leave. The prefrontal cortex is important for impulse control, also called 'inhibitory' control, the ability to inhibit our own behavior.

This is how brains would appear if you were looking down at them from the ceiling. The prefrontal cortex is toward the very front of the brain (the boxes are around part of the prefrontal cortex on the right side of the brain). The darkest colors (blue and purple) represent the areas that are most fully developed. The bright green color of the prefrontal cortex in the teen brain shows that it has not fully developed yet.
These brain images show the parts of the brain that reach maturity first.   The prefrontal cortex doesn't become fully developed until after adolescence. So it's not surprising that when we're young we're not very good at stopping whatever we're doing in order to arrive on time for our next appointment. Since I received my Mickey Mouse gift as I was graduating college, I'm happy to see in these images that even the 20-year-old brain lacks a fully developed prefrontal cortex.

Of course being late doesn't necessarily mean that you're lacking the neural machinery to be on time. Even in college, I don't remember arriving late to many movies, or often arriving late to meet a girl for a date.  As is often the case, when our motivation is strong we become very good at tapping into our abilities. 

But arriving on time to see a movie, or for a date, doesn't take a lot of self control. When our actions are guided by our desires of the moment, when we are choosing to do the thing we expect to be most pleasurable, we are not exercising self control. In fact brain imaging studies show that the inhibitory control areas of the prefrontal cortex do not become activated under these types of conditions. Self control comes into play when we choose to do the thing that we do not expect to be most pleasurable at the moment, but which we think will bring us more pleasure (and/or less pain) over the long run. That's really what I was lacking in college, and to some degree lacking today as well.

Then again, self control isn't everything, and, as you can see in the images above, the prefrontal cortex isn't the only brain area. It's just one tool in our mental toolbox.