Influence of feedback transparency on motor imagery neurofeedback performance: the contribution of agency

Abstract

ObjectiveNeurofeedback (NF) is a cognitive training procedure based on real-time feedback (FB) on the participant’s brain activity that they must learn to self-regulate. The visual FB traditionally delivered in a NF task manifests as a filling gauge reflecting a measure of brain activity. This abstract visual FB is not transparently linked—from the subject’s perspective— to the task performed (e.g., motor imagery). This may decrease the sense of agency, the participants’ reported control over FB. We assessed the influence of FB transparency on NF performance and the role of agency in this relationship.ApproachParticipants performed a NF task using motor imagery to regulate brain activity measured using electroencephalography. In separate blocks, participants experienced three different conditions designed to vary transparency: FB was presented as either 1) an oscillating pendulum, 2) a clenching virtual hand, 3) a clenching virtual hand combined with a motor illusion induced by tendon vibration.Main resultsWe found that FB transparency influences NF performance. Transparent visual FB provided by the virtual hand resulted in significantly better NF performance than the abstract FB of the pendulum. Surprisingly, adding a motor illusion to the virtual hand significantly decreased performance relative to the virtual hand alone. We found that self-reported agency was significantly associated with NF performance at the within-subject level across all FB types.SignificanceOur results highlight the relevance of transparent FB but also the importance of FB eliciting a strong sense of agency. This factor is likely an important consideration in designing multimodal FB, which while usually recommended, should be tailored to maximize the sense of agency in order to improve NF performance and learning outcomes.