How Much Do Strategy Reports Tell About the Outcomes of Neurofeedback Training? A Study on the Voluntary Up-Regulation of the Sensorimotor Rhythm

Abstract

The core learning mechanisms of neurofeedback (NF) training are associative, implicit, and, consequently, largely impervious to consciousness. Many other aspects of training that determine training outcomes, however, are accessible to conscious processing. The outcomes of sensorimotor rhythm (SMR) up-regulation training are related to the strategies reported by participants. The classification methods of individual strategies employed hitherto were possibly under influence of the idiosyncratic interpretation of the rater. To measure and possibly overcome this limitation, we employed independent raters to analyze strategies reported during SMR up-regulation training. Sixty-two healthy young participants took part in a single session of SMR up-regulation training. After completing six blocks of training, in which they received either simple visual feedback or a gamified version thereof, participants were required to report the strategies employed. Their individual learning outcomes were computed as well. Results point out that individual strategies as well as NF learning outcomes were not particularly sensitive to the presence of gamified elements in training the SMR up-regulation. A high degree of consistency across independent raters classifying strategy reports was observed. Some strategies were more typical of responders while other ones were more common among non-responders. In summary, we demonstrate a more objective and transparent way to analyze individual mental strategies to shed more light on the differences between NF responders and non-responders.

Differential Effects of Up- and Down-Regulation of SMR Coherence on EEG Activity and Memory Performance: A Neurofeedback Training Study

“…Before and after the 10 NF training sessions, resting EEG measurements with open eyes with a duration of 1 min each were performed. After the first, fifth, and tenth NF training session, we asked the participants to verbally describe their mental strategies, which they have used to control the feedback bars (Kober et al, 2013(Kober et al, , 2017cDavelaar et al, 2018;Autenrieth et al, 2020).…”

“…These reports were analyzed descriptively to reveal possible relationships between the used mental strategies and the ability to up-/down-regulate SMR coherence. Prior amplitude-based NF studies showed that the used mental strategy might be informative for the NF training success (Nan et al, 2012;Kober et al, 2013Kober et al, , 2017cAutenrieth et al, 2020).…”

Prefrontal Asymmetry BCI Neurofeedback Datasets

“…For instance, imagining a gesture would activate corresponding pre-motor areas, pleasant autobiographic memories can affect PFC asymmetry, concentrating on your inner self may activate the insula (Lawrence et al, 2014), and achieving a relaxed state may decrease the amygdala activity. Cognitive strategies may be suggested by the experimenter, or may be discovered by the subjects themselves based on the (often partial) experimental brief they have been given (Autenrieth et al, 2020). Some of the cognitive strategies may actually lack specificity: for PFC asymmetry in which valence and approach may be confounded, the use of positive autobiographic memories as a cognitive strategy may actually bias activation from a valence perspective.…”

“…In terms of experimental protocol and validation, clinical NF tends to rely on sham feedback as a control group, under the hypothesis that appropriate feedback provides the reward signal that mediates long-term effects. The clinical context implies and allows the use of repeated sessions with significant training, which increases the number of responders: on the other hand, BCI NF dedicates limited time to subjects training and leaves non-responders to the various categories of BCI illiteracy (Lee et al, 2014;Trambaiolli et al, 2018;Autenrieth et al, 2020), concentrating instead on the responders' behavior.…”

“…Our three datasets also cover a range of cognitive strategies, ranging from explicitly expressing a given feeling [ANG], engaging with a virtual character [RAP], or expressing motivation [HEU]. We collected post-experiment user feedback (Autenrieth et al, 2020) on the actual cognitive strategies they used for NF: it highlighted a mix of through contents related to both approach and positive valence, apparently influenced by the visual nature of the application. Users reported various sorts of mental "cheering" as if encouraging runners during a race, as well as the use of more abstract thinking strategies to generate a feeling of eagerness, such as reminiscence of appetitive stimuli or pleasant memories.…”