Altered frontal EEG asymmetry in obsessive-compulsive disorder

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Hemispheric asymmetry in alpha band power is associated with approach/avoidance motivation.
• This asymmetry may serve as an indicator for anxiety disorders and depression risk.

Purpose of the Study:

• To investigate the hemispheric topography of lower alpha band power (8-10 Hz) in individuals with obsessive-compulsive disorder (OCD).
• To compare these patterns between OCD patients and healthy controls during various visual stimuli conditions.

Main Methods:

• Electroencephalogram (EEG) was used to measure lower alpha band power (8-10 Hz).
• Twenty OCD patients and 20 matched healthy controls participated.
• EEG data were collected during rest and while viewing neutral, aversive, and OCD-related images.

Main Results:

• OCD patients displayed significantly altered frontal alpha band asymmetry compared to controls.
• Left-hemisphere dominance in frontal 8-10 Hz alpha power was observed across all conditions in OCD patients.
• This altered asymmetry was specific to the lower alpha band and frontal regions, not observed in parietal areas or other frequency bands (upper alpha, theta, beta).

Conclusions:

• The findings support the hypothesis of heightened avoidance motivation in OCD, indicated by altered hemispheric alpha power topography.
• The observed altered asymmetry appears to be a trait-like characteristic in OCD.
• This neurophysiological difference may suggest a potential link between OCD and depressive disorders.