Research Article: 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

Date Published: September 4, 2019

Publisher: Public Library of Science

Author(s): Adrian Naas, João Rodrigues, Jan-Philip Knirsch, Andreas Sonderegger, Natasha M. Maurits.

http://doi.org/10.1371/journal.pone.0211668

Abstract

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.

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.

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.

Partial Text

The growing number of college students using drugs like Methylphenidate (MPH, Ritalin) or Modafinil to enhance concentration, memory performance and wakefulness (16% on some college campuses, see e.g. [1–3]) can be considered an alarming indicator for the need of cognitive enhancement in our society. Rather than deploring this trend, the aim of this piece of research is to examine the usefulness of alternative methods for cognitive enhancement such as the non-invasive technique of neurofeedback training (NFT). Previous research addressing this topic has reported some evidence for a positive effect of NFT on cognitive performance. However, to our knowledge, no study has tested the effectiveness of NFT with a not-medical grade EEG. This gap in current research leaves the average consumer torn between the glorious slogans of a booming brain computer interface (BCI) industry with their easy-to-use and low-priced devices and a common sense which tries to disentangle advertising from possibility and innovation. The task is further exacerbated by the scientific field which suffers from the problem of publication bias (e.g. [4]), with methodologically problematic designs (e.g. no-intervention control groups) which make it difficult to give a clear statement about the usefulness of NFT for cognitive performance.

The present study investigated if a commercially available BCI device (Emotiv Epoc) used as a NFT device enables volitional control and enhancement of EEG activity and reveals the connection between IUA alpha NFT, relative alpha and short-term memory performance using a commercially available BCI device (Emotiv Epoc) in a single-blind design. In line with previous results [5], an enhancing effect of the training on the relative alpha and on short-term memory performance (digit-span Task) was expected.

 

Source:

http://doi.org/10.1371/journal.pone.0211668

 

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