“Devilish’ brain to blame for our bad eating habits
Researchers in the US discovered an “angel” centre in the brain that holds back a “devil” region to stop us giving in to temptation.
It allows people to weigh abstract considerations such as “healthiness” against basic desires – for instance, a craving for tasty, rich food.
However, scientists found that the effect is strong in individuals with good self control but less pronounced in the weak-willed.
Dr Antonio Rangel, from the California Institute of Technology, whose research appears in the journal Science, said: “A very basic question in economics, psychology, and even religion, is why some people can exercise self-control but others cannot. From the perspective of modern neuroscience, the question becomes, “what is special about the circuitry of brains that can exercise good behavioural self-control?’ This paper studies this question in the context of dieting decisions and provides an important insight.”
Dr Rangel’s team showed a group of dieting volunteers photos of 50 foods ranging from chocolate bars to cauliflower.
Participants were asked to rate each food according to its taste and healthiness.
A “reference” food was then picked for each person which he or she regarded as neutral with respect to taste and health. They were then asked to choose between their reference foods and other dishes, while their brain activity was scanned.
A pattern emerged as participants with strong self control signals were able to balance health and taste and opt for healthier foods. Those whose “angels” did not speak loudly enough chose the tastier foods, regardless of nutritional value.
“After centuries of debate in social sciences we are finally making big strides in understanding self-control from watching the brain resist temptation directly,” said co-author Prof Colin Camerer. “This study, and many more to come, will eventually lead to much better theories about how self-control develops and how it works for different kinds of temptations.”
The “angel” centre’s technical name is the dorsolateral prefrontal cortex (DLPFC). Researchers hope to find ways to engage this in people with poor self control – for instance, it might be possible to kick it into gear by making the health qualities of foods more obvious, they said.
