Some CalTech scientists think that using brain scans and food choices they have been able to identify the part of the brain that allows people control their desires and refrain from making harmful decisions. If you can say no to unhealthy food you probably have a fairly strong dorsolateral prefrontal cortex (DLPFC) in your brain
After all the choices had been made, the researchers were able to pick out 19 volunteers who showed a significant amount of dietary self-control in their choices, picking mostly healthy foods, regardless of taste. They were also able to identify 18 additional volunteers who showed very little self-control, picking what they believed to be the tastier food most of the time, regardless of its nutritional value.
When they looked at the brain scans of the participants, they found significant differences in the brain activity of the self-control group as compared to the non-self-controllers.
Previous studies have shown that value-based decisions--like what kind of food to eat--are reflected in the activity of a region in the brain called the ventromedial prefrontal cortex, or vmPFC. If activity in the vmPFC goes down, explains Todd Hare, a postdoctoral scholar in neuroeconomics and the first author on the Science paper, "it means the person is probably going to say no to that item; if it goes up, they're likely to choose that item."
In the non-self-controllers, Rangel notes, the vmPFC seemed to only take the taste of the food into consideration in making a decision. "In the case of good self-controllers, however, another area of the brain--called the dorsolateral prefrontal cortex [DLPFC]--becomes active, and modulates the basic value signals so that the self-controllers can also incorporate health considerations into their decisions," he explains. In other words, the DLPFC allows the vmPFC to weigh both taste and health benefits at the same time.
"The vmPFC works during every decision," says Hare. "The DLPFC, on the other hand, is more active when you're employing self-control."
"This, ultimately, is one reason why self-controllers can make better choices," Rangel adds.
Still, the DLPFC can only do so much. For instance, it can't override a truly negative reaction to a food, notes Hare. "We rarely got people to say they'd eat cauliflower if they didn't like cauliflower," he says. "But they would choose not to eat ice cream or candy bars, knowing they could eat the healthier index food instead."
Suppose neural stem cell therapy could boost the power of your dorsolateral prefrontal cortex. Would opt for the cell therapy that would do this?
I expect future prospective parents will gain the option of boosting and dampening various brain genes. I expect most prospective parents will opt for genetic twiddling that will boost the power of the dorsolateral prefrontal cortex. So people of the future will be more self-controlled.
|Share |||Randall Parker, 2009 May 01 12:24 AM Brain Appetite|