Embodied neurofeedback with an anthropomorphic robotic hand.

Niclas Braun,Jeremy D Thorne,Stefan Debener,Reiner Emkes

doi:10.1038/srep37696

Niclas Braun, Jeremy D Thorne + Show 2 more

Open Access

https://doi.org/10.1038/srep37696

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Abstract

Neurofeedback-guided motor imagery training (NF-MIT) has been suggested as a promising therapy for stroke-induced motor impairment. Whereas much NF-MIT research has aimed at signal processing optimization, the type of sensory feedback given to the participant has received less attention. Often the feedback signal is highly abstract and not inherently coupled to the mental act performed. In this study, we asked whether an embodied feedback signal is more efficient for neurofeedback operation than a non-embodiable feedback signal. Inspired by the rubber hand illusion, demonstrating that an artificial hand can be incorporated into one’s own body scheme, we used an anthropomorphic robotic hand to visually guide the participants’ motor imagery act and to deliver neurofeedback. Using two experimental manipulations, we investigated how a participant’s neurofeedback performance and subjective experience were influenced by the embodiability of the robotic hand, and by the neurofeedback signal’s validity. As pertains to embodiment, we found a promoting effect of robotic-hand embodiment in subjective, behavioral, electrophysiological and electrodermal measures. Regarding neurofeedback signal validity, we found some differences between real and sham neurofeedback in terms of subjective and electrodermal measures, but not in terms of behavioral and electrophysiological measures. This study motivates the further development of embodied feedback signals for NF-MIT.

Highlights

In Neurofeedback-guided motor imagery training (NF-MIT), the desired motor percept is top-down generated by cognition, since here the participants self-induce the motor percept by mental rehearsal alone[15]
Whereas in NF-MIT the patient is supported by a neurofeedback signal, which helps to perform the mental act and facilitates imagery-induced motor cortex activation[30,31], no neurofeedback signal can typically be provided in MVF
We developed a new NF-MIT that employs an embodiable neurofeedback signal

Summary

Introduction

In NF-MIT, the desired motor percept is top-down generated by cognition, since here the participants self-induce the motor percept by mental rehearsal alone[15]. In most NF-MITs, the feedback signal is rather abstract and not inherently coupled to the mental act performed[17]. In NF-MIT the motor percept is self-constructed by mental imagery whereas in MVF it is bottom-up induced by the sensory input. Whereas in NF-MIT the patient is supported by a neurofeedback signal, which helps to perform the mental act and facilitates imagery-induced motor cortex activation[30,31], no neurofeedback signal can typically be provided in MVF. We asked whether NF-MIT performance and SoA depend on the validity of the neurofeedback signal. This was done by including a sham feedback condition in which the provided feedback was not based on real-time brain activity

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