Haptic perception and EEG power changes in anorexia nervosa

Objectives: We predicted tl-tat due to diminished somatosensory integrative ability, the anorectic patients would have problems reproducing haptic sti muli. In addition we sought to determine whether EEGs from anorectic patien ts (AN) and the healthy controls (CO) would show discrepancies between the two groups during haptic explorations in theta-power over the right parieta l region. Method: EEG power (theta-power:) data of AN (n = 13) and CO (n = 13) were a nalyzed during haptic exploration tasks and rest intervals. The haptic expl orations consisted of palpating the structure of six sunken reliefs in sequ ence with both hands, eyes closed, After each exploration the structure was drawn on a piece of paper. Results: The reproductions of haptic stimuli submitted by the anorectic pat ients were of notably poorer quality than those of the healthy controls. Du ring rest intervals and haptic explorations, spectral power was generally l ower in the AN group in comparison to the healthy controls. Significant the ta-power differences between groups showed over the right parietal cortex d uring haptic explorations. The decrease in EEG power in the anorectic patie nts in thr theta bands across the right parietal region during haptic explo ration tasks could be interpreted as a minor activation of visuo-spatial re gions. The results of the haptic explorations as well as the EEG-power chan ges indicate a cortical dysfunction and deficits in somatosensory integrati on processing in anorexia nervosa patients.