I recently read an article in The Journal of Neuroscience titled “Focusing Attention on the Health Aspects of Foods Changes Value Signals in vmPFC and Improves Dietary Choice.”
It contains a lot of science, obviously, and a lot of fMRI work, which I won’t discuss. Some people don’t think science is too sexy and I don’t want anyone to just skip the post, so I will just talk about the behavioral aspects and findings.
People make food decisions by assigning values to short-term and long-term consequences, including things like taste, healthiness, size, and packaging for foods.
Researchers were interested in whether extrinsic cues that ask participants to pay attention to the health of a given food affect their food choices (i.e., do they in fact pick the healthier options), particularly in non-self controllers, as self-controllers do this intrinsically. With food, self-control is often an issue and they wanted to see if manipulating attention could improve decision-making.
Part of why self-control is such an issue may be “a tendency of the valuation circuitry to overweight short-term (e.g., taste) relative to long-term features (e.g., healthiness).
33 subjects who were not dieting or had any dietary restrictions rated and made decisions on a 4 point scale (Strong No, No, Yes, and Strong Yes) for 180 foods for which they were shown pictures. Junk foods and healthy foods were included.
That they were not trying to lose weight is important. I wonder if BMI would have been too, although I’m not sure why I think this might be useful information. It would have certainly been more relevant than the fact that they were right-handed, at least. It also would have been nice to know what people’s eating habits were like beforehand, if that was possible, as well as if they had recently or ever dieted or had self-imposed dietary restrictions.
They were asked to make decisions under 3 different conditions: 1) being asked to consider health before choosing; 2) being asked to consider taste before choosing; and 3) being asked to consider whatever features came to mind.
They were also told to, regardless of the condition, choose the food they preferred.
Subjects did in fact make healthier choices with the aid of extrinsic cues.
More specifically, in the health condition, subjects responded more to the health of the food than did the neutral condition and less responsive to the taste of the food. In the taste condition, they cared less about the health than in the neutral condition, but were not significantly more responsive to the taste. There were no differences in the choices of food in this condition, which the authors attributed to the fact that since subjects weren’t dieting, maybe they already highly weighted taste in the neutral condition, making the taste cue not matter, and again, makes me wish their dietary habits and food choices prior to the study were known.
The results suggest that “there is room for health attention cues to increase health weighting in the computation of stimuli” and that “a natural way to exercise self-control is to modulate value signals so that [people] properly weight long-term considerations such as health.” Further, this is evidence that exogenously directing attention to a specific feature, like health, can increase its relative weighting when deciding on values which are made at every point up until the decision is made.
The only thing I will say about the fMRI aspect is that when health cues were given, there was increased activity in two parts of the brain that are physically close to those involved in self-control in people who are dieting, and these parts of the brain also affect cognitive control, memory, and emotion recognition.
randi morse, randi.morse@gmail.com, newton, ma
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