Using brain imaging, they pinpointed differences in the formation of regular binge eating habits. Binge eating is characterized by the excessive intake of large amounts of food in a short period of time. Frequent overeating can be triggered by a number of stimuli, whether they are external – the enticing smell of attractive-looking food, or internal – overeating can be a coping mechanism for feelings of sadness, stress, or dissatisfaction. Such behavior can often be compulsive, uncontrolled by the one who indulges in it.
The similarity between food cravings and addictive states has raised the question of the connections between structures in the brain – in addictions there are key changes in the brain circuits involved in habit formation.
For analysis, scientists take functional magnetic resonance (fMRI) images. A sector of the brain called the striatum or striatum was studied. This part of the brain is closely related to habit formation. A particular object of observation is a part of the striatum called the sensorimotor putamen, which has connections with senses, sensations, and motor activity.
The fMRI images of the volunteers were compared with samples without regular binge eating. Substantial differences in neuronal circuits in the sensorimotor putamen were observed. The connection of this part of the striatum was stronger with the parts of the cerebral cortex responsible for movement and sensation. Thanks to this strengthened connection, someone who tends to overeat can smell food much more strongly and alluringly. Decreased levels were also observed in the part of the brain responsible for self-control.
These tendencies increase with the frequency and severity of binge eating in a given instance, indicating a tendency to lose self-control in the presence of an impulse, internal or external.
Additional observations in cases with altered brain connections showed reduced sensitivity to dopamine in these regions. Dopamine desensitization may be due to sustained high levels of dopamine through repeated exposure to rewarding stimuli such as eating.
Disruptions in habit-related brain circuits are also a factor in addiction-related psychiatric disorders. Increasing knowledge about brain connections will improve therapies such as deep brain stimulation that directly affect the activity of neurons in the brain. This study also shows that this eating disorder most likely results from changes in the brain. The information may serve as a kind of reassurance to those who regularly exhibit such behavior.
Alan Wang, a medical student at Stanford University and an author of the study, said: “I think there is also some psychological benefit for patients, as they can reframe this behavior as habit-based. Eating disorders are not a flaw in their character. They are associated with physical changes in the brain.”