New research has found that women with anorexia have below-average activity in brain regions that help coordinate social behavior.  The observations were made as the women played a computer game stressing cooperation.  The researchers also showed that women with the disorder tended to blame themselves more than others for negative social interactions —highlighting social deficits as an important target for treating anorexia.

Comparing women with anorexia and women who had gained back weight while recovering from anorexia with women who never had the illness, the research team, led by 2012 NARSAD Young Investigator grantee Carrie J. McAdams, M.D., Ph.D., of the University of Texas Southwestern Medical School, measured the women’s brain activity and behavior during a game that depends on trust between players.Each woman in the study played the cooperation game with a computer simulator but thought she was playing with an actual person, online. The simulator and each woman traded offers of money. Each offer was mathematically classified as either “benevolent” or “malevolent” depending on whether more or less money was being offered relative to offers made in the preceding rounds. In this way, researchers simulated responses of the brain to both improvement and deterioration of a social relationship.

In their report on the experiment, published online September 29, 2015 in Human Brain Mapping and partially funded by a NARSAD grant, Dr. McAdams’ team found that a history of anorexia predicted unusual responses both to benevolent and malevolent exchanges.

Compared to the women who never experienced anorexia and the women recovered from it, those still living with anorexia showed reduced activity in brain regions (within the brain’s temporal and occipital lobes) during malevolent interactions. Additionally, the women currently with anorexia but not the other groups rated themselves as being responsible for more negative than positive social interactions. In contrast, the women recovered from anorexia behaved less stingily when they experienced malevolence. In sum, recovery from anorexia included improvements in both detection and responses to negative social interactions.  

Benevolent exchanges led to a different pattern. Both the women living with and those recovered from anorexia showed unusually low activity in brain areas related to positive social evaluations (in the temporal and parietal lobes) when experiencing a benevolent offer. These results suggest that the experience of anorexia involves impaired processing of positive social interactions. The authors say this suggests that difficulty recognizing positive interactions may be a trait that precedes anorexia, perhaps predisposing young women to develop it, though more research is needed to investigate this possibility.

Excitingly, the authors also identified a self-report measure about positive social perceptions that correlated with neural activations during benevolent exchanges. This scale could help lead to development of an effective screen or target for new interventions focusing on social perception in anorexia.