Neurofeedback training with a low-priced EEG device leads to faster alpha enhancement but shows no effect on cognitive performance: A single-blind, sham-feedback study

Abstract

Introduction Findings of recent studies indicate that it is possible to enhance cognitive capacities of healthy individuals by means of individual upper alpha neurofeedback training (NFT). Although these results are promising, most of this research was conducted based on high-priced EEG systems developed for clinical and research purposes. This study addresses the question whether such effects can also be shown with an easy to use and comparably low-priced Emotiv Epoc EEG headset available for the average consumer. In addition, critical voices were raised regarding the control group designs of studies addressing the link between neurofeedback training and cognitive performance. Based on an extensive literature review revealing considerable methodological issues in an important part of the existing research, the present study addressed the question whether individual upper alpha neurofeedback has a positive effect on alpha amplitudes (i.e. increases alpha amplitudes) and short-term memory performance focussing on a methodologically sound, single-blinded, sham controlled design. Method Participants (N = 33) took part in four test sessions over four consecutive days of either neurofeedback training (NFT group) or sham feedback (SF group). In the NFT group, five three-minute periods of visual neurofeedback training were administered each day whereas in the SF group (control group), the same amount of sham feedback was presented. Performance on eight digit-span tests as well as participants’ affective states were assessed before and after each of the daily training sessions. Results NFT did not show an effect on individual upper alpha and cognitive performance. While performance increased in both groups over the course of time, this effect could not be explained by changes in individual upper alpha. Additional analyses however revealed that participants in the NFT group showed faster and larger increase in alpha compared to the SF group. Surprisingly, exploratory analyses showed a significant correlation between the initial alpha level and the alpha improvement during the course of the study. This finding suggests that participants with high initial alpha levels benefit more from alpha NFT interventions. In the discussion, the appearance of the alpha enhancement in the SF group and possible reasons for the absence of a connection between NFT and short-term memory are addressed.

Neurofeedback of Alpha Activity on Memory in Healthy Participants: A Systematic Review and Meta-Analysis

“…The results indicate a positive effect of the alpha NFT on memory. In addition, the control groups of most included studies (9 of 14 WM studies and 4 of 6 EM studies) (1 study with active neurofeedback (Pei et al, 2018), 2 studies with sham neurofeedback (Guez et al, 2014;Xiong et al, 2014), or 8 studies with silent feedback (Escolano et al, 2011;Lecomte and Juhel, 2011;Zoefel et al, 2011;Alekseeva et al, 2012;Reis et al, 2016;Farnia et al, 2017;Gordon et al, 2019;Naas et al, 2019) showed no memory change. Two active control groups showed significant improvement in WM and EM after training (Hsueh et al, 2016;Wei et al, 2017), and the alpha group of the two studies exhibited significant enhancement of WM and EM compared with the active control group.…”

Brain Exercising Games With Consumer-Grade Single-Channel Electroencephalogram Neurofeedback: Pre-Post Intervention Study

“…Evidently, the published results to date are variable. For example, Gadea et al [66] [67][68][69] reported successful voluntary modulation of brain activity (change in the EEG signal) but no effects on the behavior (eg, symptom reduction). Both effects were shown in other studies [70][71][72][73][74].…”

Alpha activity neuromodulation induced by individual alpha-based neurofeedback learning in ecological context: A double-blind randomized study

“…used EEG-based NFT of sensorimotor rhythm regulation over multiple sessions but did not find evidence for between session neuromodulation [29]. Naas et al [30] used an NF protocol targeting upper alpha band over four training sessions in four days and did not reveal any significantly different positive improvement of the targeted activity between groups over time. In contrast, Beatty [31] showed an increase of the trained alpha activity in the NF group but not in the sham-FB condition during a unique NF session.…”

“…However, the neurocognitive mechanisms underlying BCI tasks or NF training (NFT) remain elusive 17,18 . The neuromodulation associated with NFT has already been studied in several contexts [19][20][21] , but this was not yet done in a long-term, multiple-session (12 weeks), sham-controlled design using an ecological reinforcer NF context for both NF and control groups.…”

“…In some NF studies, the control condition was based on linking the feedback to another brain activity than the targeted one 22,35 which entails an incongruity between the activity driving the feedback and the task-hence the cognitive effortsof the subject. Here, we used a sham feedback (sham-FB) condition for the control group-as it is commonly used in other studies including MEG or fMRI NF protocols [19][20][21][22][36][37][38][39] . The participants in the sham-FB group received 'yoked' feedback, corresponding to the feedback of randomly-chosen subjects from the NF group at the same stage of learning.…”