“…Twelve studies investigated multiple EEG measurement or signal processing techniques ( Khaliliardali et al, 2012 , 2015 ; Singh et al, 2016 ; Jeong et al, 2017 ; Sburlea et al, 2017 ; Rashid et al, 2018 ; Eilbeigi and Setarehdan, 2018a , b ; Karimi and Jiang, 2019 ; Moinnereau et al, 2019 ; Russo et al, 2019 ; Schwarz et al, 2020a ). The six experimental studies consisted of two randomized controlled trials ( Mizusaki et al, 2019 ; Peters et al, 2020 ), one non-randomized controlled trial ( Fromer et al, 2016 ), one randomized cross-over trial ( Barthel et al, 2001 ), one non-randomized cross-over trial ( Mrachacz-Kersting et al, 2019a ), and one non-controlled trial ( Wright et al, 2012a ).…”