Angle paradigm: A new method to measure right parietal dysfunctions in anorexia nervosa

Background: A functional disturbance of the right parietal cortex (PC) is supposed to be responsible for the distorted body image in patients with anorexia nervosa (AN). Based on this assumption, we investigated changes in haptic perception with a new experimental design. Method: Thirty-two subjects (16 AN patients and 16 healthy controls) were asked to readjust a given angle adjustment without visual feedback. This arrangement allowed to measure the deviation of the adjusted angle from the locked angle on an interval scale. Results: AN patients performed worse when they were asked to readjust the angle with the right hand, i.e., the deviation of the readjusted angle from the given angle was higher compared to the healthy controls for right side tasks. Conclusions: The capacitive strain of the right PC is substantially stronger in right side tasks with the consequence that the functionally disturbed right PC of AN patients cannot provide enough processing resources.