Some Caltech researchers found that the dorsolateral prefrontal cortex (dlPFC) in the brain exerts self control to make people make healthier decisions and it is possible to make the dlPFC more active to improve your food choices.
When you decide what to eat, not only does your brain need to figure out how it feels about a food's taste versus its health benefits versus its size or even its packaging, but it needs to decide the importance of each of those attributes relative to the others. And it needs to do all of this more-or-less instantaneously.
Antonio Rangel, professor of economics and neuroscience at Caltech, has been studying this value-deriving and decision-making process for years now. Along with Todd Hare—a former postdoc at Caltech who is now an assistant professor of neuroeconomics at the University of Zurich in Switzerland—he published a paper in Science in 2009 describing differences in the brains of people who are better at exercising self-control than others. What they found was that while everyone uses the same area of the brain—the ventral medial prefrontal cortex, or vmPFC—to make value-laden decisions like what to munch on, there's a second brain area—the dorsolateral prefrontal cortex, or dlPFC—that seems to come to life when a person is using self-control during the decision-making process.
In other words, when the dlPFC is active, it allows the vmPFC to take into account health benefits as well as taste when it assigns a value to a particular food.
Imagine a gene therapy or cell therapy that long term boosts the level of dlPFC activity to basically change your preferences for food and likely for other things as well.
Before showing series of pictures of food to say yes or no to the researchers showed one of the messages "consider the healthiness," "consider the tastiness," or "make decisions naturally." The "consider the healthiness" image caused subjects to choose healthier foods and that image made their dorsolateral prefrontal cortex more active.
Things got interesting when the researchers looked at the other three categories, however. Among their findings:
- When thinking about healthiness, subjects were less likely to eat unhealthy foods, whether or not they deemed them to be tasty, and more likely to eat healthy-untasty foods.
- Being asked to think about healthiness led subjects to say "no" to foods more often than they did when asked to make decisions naturally.
- There were no real differences between the choices made during the "consider the tastiness" and "make decisions naturally" portions of the experiment.
When the researchers turned to the fMRI results, they found that the vmPFC was, as predicted, "more responsive to the healthiness of food in the presence of health cues," says Rangel. And, as they'd seen previously, the robustness of that response was due to the influence of the dlPFC—that bastion of self-control—which was much quieter when the study's subjects were thinking about taste or their own personal choice than when they were asked to throw healthiness into the equation.
How about "consider the healthiness" pasted in your refrigerator door? Where its really needed: on the entrance of fast food joints.
|Share |||Randall Parker, 2011 July 27 08:27 AM Brain Appetite|