Anorexics And Obese Individuals Shown To Have Opposite Brain Reward Response

A new study published in the journal Neuropsychopharmacology has provided experimental evidence for opposite brain reward responses in individuals with obesity and anorexia.

The researchers wanted to determine whether or not rewards are perceived differently by the brain in persons suffering from eating disorders such as anorexia. They suspected that obese individuals would demonstrate a “blunted” response to reward compared to persons with anorexia who they believed would reveal an enhanced reward response.

Expectation of reward “blunted in obese individuals

The study involved 21 individuals diagnosed with anorexia (food restricting type), 19 persons suffering from obesity, and 23 control participants. The first test involved administering solutions of sucrose and artificial saliva in order to determine whether or not the participants experienced a difference in taste which they did not.

The second part of the experiment involved providing a conditioned stimulus that would cause the study participants to expect a reward. This was done while having the participants undergo a functional MRI which is used to measure brain activity by detecting changes in blood flow to certain regions in the brain. A sucrose solution was usually offered following a conditioned stimulus, but not always.

Compared to anorexic persons and control subjects, the obese individuals were less likely to associate the expectation of receiving a reward (in this case, the sucrose solution) with the conditioned stimulus.

Reward response of anorexic participants opposite to that of obese individuals

In contrast to the obese individuals and control participants, anorexic participants demonstrated greater sensitivity regarding reward activation in the orbitofrontal cortex of the brain, especially when anticipating the sucrose solution following the conditioned stimulus. When the anorexic individuals expected to receive the sucrose solution but instead were given the artificial saliva, they registered more error reward responses.

More research is needed to further explore the reward response mechanisms in the brains of individuals with eating disorders such as anorexia. An increased understanding of the role of the neurotransmitter dopamine could also offer hope for the development of future treatments.

Source: Scientific American

Eating Disorder Self Test. Take the EAT-26 self test to see if you might have eating disorder symptoms that might require professional evaluation. All answers are confidential.

Find a Treatment Facility Near You

Click on a state below to find eating disorder treatment options that could be right for you.

The information provided on EatingDisorders.com is designed to support, not replace, the relationship that exists between a patient/site visitor and his/her health professional. This information is solely for informational and educational purposes and we encourage all visitors to see a licensed physician if they believe that they have an eating disorder. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Neither the owners or employees of EatingDisorders.com nor the author(s) of site content take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading this site. Always speak with your primary health care provider before engaging in any form of self treatment. Please see our Legal Statement for further information.

Copyright © 2008-2017 EatingDisorders.com.
Company Information

© 2017 EatingDisorders.com. All rights reserved. Use of this site constitutes acceptance of EatingDisorders.com's terms of service and privacy policy. The material on this site is for informational purposes only, and is not a substitute for medical advice, diagnosis or treatment provided by a qualified health care provider.