Comparison of Theta/Beta, Slow Cortical Potential, and Adaptive Neurofeedback Training in Adults: Training Effects on Attentional Processes, Motor System, and Mood

Objective: Neurofeedback (NF) training is being applied in an increasing number of clinical and peak performance fields. Better controlled NF studies with larger sample sizes are being conducted, aiming at gaining insights into the specific effects of particular NF protocols together with the underlying mechanisms mediating a successful training. The aim of the present investigation was three-fold. It set out to examine the effects of different NF protocols on well-being / mood, to evaluate the effects of an adaptive type of NF training, as well as to shed further light on the neuronal mechanisms underlying different NF protocols with respect to attentional processes and motor system excitability. Methods: ‘Healthy’ adults (n = 73) were randomly allocated to one of four groups: a theta/beta neurofeedback, a slow cortical potential (SCP) neurofeedback, an adaptive neurofeedack (ANF), or a control training group. Neurofeedback training consisted of 10 double sessions. Preand post-training assessments encompassed both self-report and performance measures in addition to resting EEG and event-related potential (ERP) recordings as well as measurements based on transcranial magnetic stimulation (TMS). Self-report measures comprised the domains attention, well-being / mood, and personality characteristics. Performance measures assessed working memory, motor skills, as well as attentional skills during the Attention Network Test (ANT). ERPs recorded during the ANT were analyzed focusing on the contingent negative variation (CNV), reflecting anticipation and preparation, as well as on cueand target-P3 amplitudes which are thought to be related to attentional resource allocation. TMS measurement was based on a double pulse paradigm applied during a resting state to assess short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF). In addition, self-regulation skills acquired during theta/beta and SCP training were analyzed and associated with behavioral and ERP measures. Results: Overall, pre-post improvements were observed independent of type of group in the domains action-orientation, self-access, and in tendency for attention, while an overall decrease in vigor was observed. Participants showed faster and less variable responses during the ANT, improved working memory, and improved darts performance. Resting EEG measures revealed an increase in theta and alpha activity, and a tendency for increased beta activity. No general training effects on ERP measures