Abnormal brain processing of gentle touch in anorexia nervosa

Area of Science:

• Neuroscience
• Psychiatry
• Psychology

Background:

• Body image disturbance is a key symptom of anorexia nervosa (AN).
• Emerging research indicates that aberrant touch perception may play a role in AN's underlying mechanisms.
• Understanding sensory processing in AN is crucial for developing targeted interventions.

Purpose of the Study:

• To investigate cortical processing of affective touch in women with AN using functional magnetic resonance imaging (fMRI).
• To compare brain activity related to pleasant touch perception between individuals with AN and healthy controls (HC).

Main Methods:

• fMRI scans were conducted on women with AN (n=25) and matched HC (n=25).
• Participants received gentle skin strokes and static skin indentation on the forearm.
• Ratings of pleasantness for tactile stimuli were collected post-scanning.

Main Results:

• AN participants reported significantly lower pleasantness ratings for skin stroking compared to HC.
• No significant group differences were found in primary tactile regions for the contrast between stroking and indentation.
• Reduced activity was observed in the AN group within the left caudate nucleus and bilateral lateral occipital cortex during skin stroking.

Conclusions:

• Abnormal dorsal striatum functioning in AN may impair the evaluation of pleasant tactile stimuli.
• Altered activity in the lateral occipital cortex could be associated with the disturbed body image perception characteristic of AN.
• These findings highlight potential neural correlates of altered sensory processing in anorexia nervosa.