A study published in Cerebral Cortex shows that obese children may be slower than healthy-weight children to recognize when they have made an error and correct it.
In the study, the researchers measured the behavioral and neuroelectric responses of 74 preadolescent children, half of them obese, half at a healthy weight. Children were fitted with caps that recorded electroencephalographic activity and asked to participate in a task that presented left- or right-facing fish, predictably facing in either the same or the opposite direction. Children were asked to press a button based on the direction of the middle (that is, target) fish. The flanking fish either pointed in the same direction (facilitating) or in the opposite direction (hindering) their ability to respond successfully.
“We found that obese children were considerably slower to respond to stimuli when they were involved in this activity,” said Charles Hillman, a University of Illinois Professor of Kinesiology and faculty member in the university’s Division of Nutritional Sciences.
The researchers also found that healthy-weight children were better at evaluating their need to change their behavior in order to avoid future errors. “The healthy-weight kids were more accurate following an error than the obese children were, and when the task required greater amounts of executive control, the difference was even greater,” said Hillman.
A second evaluation measured electrical activity in the brain “that occurs at the intersection of thought and action,” said Hillman. “We can measure what we call error-related negativity (ERN) in the electrical pattern that the brain generates following errors. When children made an error, we could see a larger negative response. And we found that healthy-weight children are better able to upregulate the neuroelectric processes that underlie error evaluation.”
Scientists in the Hillman lab and elsewhere have seen a connection between healthy weight and academic achievement, “but a study like this helps us understand what’s happening. There are certainly physiological differences in the brain activity of obese and healthy-weight children. It’s exciting to be able to use functional brain imaging to see the way children’s weight affects the aspects of cognition that influence and underlie achievement,” said postdoctoral researcher and co-author Naiman Khan.