Nonlinear and linear EEG complexity changes caused by gustatory stimuli in anorexia nervosa

Area of Science:

• Neuroscience
• Psychiatry
• Gastroenterology

Background:

• Anorexia nervosa (AN) is a complex eating disorder with significant neurological and sensory processing alterations.
• Electroencephalogram (EEG) complexity measures offer insights into brain function and may be affected by malnutrition and sensory deficits in AN.

Purpose of the Study:

• To investigate the impact of gustatory stimuli (pleasant and unpleasant tastes) on EEG complexity in AN patients versus healthy controls.
• To explore potential correlations between altered EEG complexity, malnutrition, and sensory processing in anorexia nervosa.

Main Methods:

• Healthy controls and AN patients were exposed to bitter tea and chocolate gustatory stimuli for 2 minutes.
• Multichannel EEG was recorded, and nonlinear (dimensional complexity) and linear (Omega complexity) measures were calculated.
• EEG data were analyzed to compare complexity between groups and across taste conditions.

Main Results:

• AN patients displayed significantly lower dimensional complexity across most recording sites compared to controls, irrespective of taste.
• Healthy controls showed higher Omega complexity on the left side, a difference not observed in AN patients.
• AN patients showed no significant change in Omega complexity on the left side in response to sweet taste.

Conclusions:

• Reduced EEG dimensional complexity in AN patients may stem from long-term malnutrition effects.
• The blunted Omega complexity response to sweet taste in AN suggests diminished sensitivity to pleasant gustatory stimuli.
• These findings highlight altered brain complexity and sensory processing in anorexia nervosa, potentially linked to malnutrition.