sentence: In total , nine studies applied digital WMT : four studies used commercially available digital WMT programs ( Cogmed and WOME / RehaCom ® ) ( Brehmer et al ., 2011 ; Tusch et al ., 2016 ; Simon et al ., 2018 ; Weicker et al ., 2018 ) , three studies used a digital n-back training ( Heinzel et al ., 2014a , b ; Matysiak et al ., 2019 ) , and two used a study – individual composition of digital WMT tasks ( McAvinue et al ., 2013 ; Borella et al ., 2014 ) .