“…The characteristics of interest (features) extracted from the brain recordings have to represent the brain patterns that one wants to modulate and provide feedback based on. In EEG, these features are often spectral bands of EEG signals (Egner & Gruzelier, 2004;Grosse-Wentrup & Schölkopf, 2014;Liu, Hou, & Sourina, 2015;Zhigalov, Kaplan, & Palva, 2016;Wei et al, 2017) or eventrelated potential (ERP) components of the signal (Farwell & Donchin, 1988;Treder & Blankertz, 2010;Zhang, Zhao, Jin, Wang, & Cichocki, 2012). Over the past 20 years, the number of journal articles about machine learning in neuroscience has grown continuously (Glaser, Benjamin, Farhoodi, & Kording, 2019).…”