bilateral Whole sample FAA and PAA A marginally significant Time × Group interactions was found when considering PAA values as the dependent variable (F(1,47) = 3.91, p = 0.054) with an increasing trend in the BS group, i.e., becoming more right-lateralized and a decreasing trend in the US group, i.e., becoming left-lateralized.
non-responders in FAA and PAA There was a significant Time × Group interaction considering PAA values as the dependent variable (F(1,23) = 5.25, p = 0.031, η 2 = 0.186, converted d = 0.956) with an increasing trend in BS responders (n = 21), i.e., becoming more right-lateralized vs decreasing in BS non-responders i.e., becoming left-lateralized.
Results Behavioral results Anhedonia and bilateral stimulation A significant Time × Group interaction in SHAPS scores (F(1,32) = 11.02, p = 0.002, η 2 = 0.256, converted d = 1.17) was found with a decreasing trend in the active group meaning that bilateral active stimulation resulted in a significant decrease in anhedonia symptoms.