Wang says that the amygdala, which is involved in emotional memory, determines what our next step should be. He says all the signals are filtered through this memory and that "our memories would let us know" whether we have eaten enough or not.
|image: Gene-Jack Wang, Brookhaven National Laboratory|
But his results showed that the amygdalas of the overweight people did not respond to the smaller volumes in the balloon.
"The most interesting is that we find that the response to this stomach expansion in the same volume, the lean person responds immediately. But the overweight person, they did not respond," says Wang.
What's more, even at the higher volumes, overweight people showed less activity in this brain area than lean people. Wang says that this stop signal is what helps people balance whether or not to stop eating.
"Turned out in the overweight person, they never receive a signal, so that's why they eat more," adds Wang.
So if overweight people lose weight, will they get this signal, or do they gain weight because they never got the signal? Wang says that is a "chicken and egg" question and scientists still do not know those answers. He hopes further studies will lead to more answers and to treatments for those with eating disorders.
PUBLICATION: NeuroImage, February 15, 2008
AUTHORS: Gene-Jack Wang, Dardo Tomasi, Walter Backus, Ruiliang Wang, Frank Telang, Allan Geliebter, Judith Korner, Angela Bauman, Joanna S. Fowler, Panayotis K. Thanos, and Nora D. Volkow
AUTHORS' INSTITUTIONS: Brookhaven National Laboratory, Mt. Sinai School of Medicine, Department of Anesthesiology of SUNY/Stony Brook, NIAAA/NIDA, St. Luke's/Roosevelt Hospital, and Columbia University, College of Physicians and Surgeons.
RESEARCH FUNDED BY: U.S. Department of Energy, the National Institute on Drug Abuse, the National Institute of Diabetes and Digestive and Kidney Diseases, the National Institute on Alcohol Abuse and Alcoholism and the GCRC at University Hospital Stony Brook