Frontal EEG resting state measures of excessive alpha-gamma PAC strength that we found in the severe AUD group has also been reported in obsessive-compulsive disorder (OCD) patients undergoing deep brain stimulation (Figee et al., 2013; Treu et al., 2021). Abnormally elevated functional connectivity of ventrolimbic corticostriatal regions in patients with OCD has been positively correlated with severity of symptoms (Harrison et al., 2009). Compared to controls, OCD patients exhibited significant increases in alpha-gamma and low beta-gamma PAC over frontal midline and parietal electrodes when deep brain stimulation (DBS) of nucleus accumbens (NAc) was turned off, and was reduced when NAc-DBS was active (Treu et al., 2021). In another study, researchers found that excessive beta-gamma PAC in fronto-striatal circuits of OCD during resting state, eyes open was reduced with deep brain stimulation (DBS) of nucleus accumbens as was symptom severity (Figee et al., 2013). Previous studies have demonstrated alpha-gamma PAC between visual cortical sources of alpha and gamma in cortical layers 2/3 and 4/5, respectively
