Aberrant somatosensory perception in Anorexia Nervosa

Area of Science:

• Neuroscience
• Psychology
• Somatosensory Research

Background:

• Anorexia Nervosa (AN) is characterized by distorted body size and shape perception.
• Previous research indicates AN patients exhibit enlarged perception of tactile distances.
• The relationship between tactile size misperception and elementary somatosensory processing in AN remains unclear.

Purpose of the Study:

• To investigate if tactile size misperception in Anorexia Nervosa relates to inaccurate elementary somatosensory perception.
• To compare tactile size estimation and elementary somatosensory perception between AN patients and controls.

Main Methods:

• Tactile size perception was assessed using the Tactile Estimation Task (TET).
• Elementary somatosensory perception was evaluated through pressure detection and two-point discrimination (TPD) tasks.
• Participants included Anorexia Nervosa patients (n=25) and healthy controls (n=28).

Main Results:

• Anorexia Nervosa patients overestimated tactile size compared to controls, with the strongest effect observed on the abdomen.
• AN patients showed altered elementary somatosensory perception, including lower abdominal pressure detection thresholds and higher TPD thresholds on the arm and abdomen.
• Regression analyses indicated that group membership and TPD significantly predicted tactile size estimation on the abdomen.

Conclusions:

• Anorexia Nervosa patients exhibit disturbances in the metric properties of their body representation, leading to overestimation of tactile stimuli size.
• Differences in elementary somatosensory perception exist between AN patients and controls.
• The misperception of tactile distances in AN is likely influenced by both bottom-up sensory processes and top-down cognitive factors.