Study Links Childhood Obesity With Decreased Cognitive Control
There have been few studies linking obesity to cognitive skills; however, at the University of Illinois, a study was undertaken to compare certain executive cognitive abilities of healthy weight pre-adolescent children with obese pre-adolescent children requiring them to respond to images of swimming fish.
The test group of 74 pre-adolescent children, half obese and half healthy weight, watched images of fish, the central fish facing in one direction and surrounding fish facing either the same (compatible) or opposite (incompatible) directions. The children were asked to identify the direction, left or right, of the central fish. The children wore caps that electrically monitored their electroencephalographic activity as they pressed a button indicating the direction of the center fish.
In addition to monitoring activities in the brain, researchers also measured behavioral responses of the children, where differences between obese and healthy weight children were observed. The following chart shows the response time and the accuracy of the children when identifying the compatible and incompatible scenes:
The obese children were slower in identifying the direction of the central fish when the "stream" around it was facing in the opposite direction of the central fish. Also, researchers found that the obese children were slower to change their executive function after making mistakes in their answers than the healthy weight children. For example, if a healthy weight child and an obese child learned that one or two of their answers were incorrect, the healthy weight child was quicker to alter the methods by which he or she identified the direction of the center fish than was the obese child. This brain function is referred to as action monitoring.
"I like to explain action monitoring this way: when you're typing, you don't have to be looking at your keyboard or your screen to realize that you've made a keystroke error. That's because action monitoring is occurring in your prefrontal cortex," said Charles Hillman, professor of kinesiology at the University of Illinois and head author of the study.
The healthy weight children exhibited action monitoring sooner and for a longer period of time than the obese children.