The relationship between EEG theta/beta ratio and response inhibition in autogenous and reactive obsessions

Obsessive-Compulsive Disorder (OCD) is a diverse mental health condition that leads to substantial impairment and currently has limited success in treatment outcomes. The aim of the current study was to examine the ratio of electroencephalographic (EEG) band power within the Autogenous-Reactive (AO-RO) taxonomy of OCD during inhibition to improve our understanding of the disorder. Inhibition was measured broadly using interference and action cancellation tasks while EEG data was recorded from 61 undergraduate students. EEG band power was computed from frontal-central electrodes Fz and Cz for theta and beta frequency bands. Event-related spectral perturbations (ERSPs) were used to measure EEG band power during inhibitory task performance to calculate the Theta/Beta ratio (TBR). The relationship between AO-RO severity and the TBR at each electrode was statistically analyzed using two hierarchical linear regressions. TBR at electrode Fz during the stop-signal task was the only significant EEG predictor of AO severity. TBR predictors were not significant for RO severity. These results suggest that AO is more strongly associated with a neural correlate of inefficient and excessive cognitive and attentional control than RO. Further research is required for determining the utility of TBR for characterizing the heterogeneity within OCD.