Sensory Feedback with a Hand Exoskeleton Increases EEG Modulation in a Brain-Machine Interface System

Abstract

Brain-machine interfaces (bci) translate brain activity into control signals of external devices, such as robots, prostheses or computers. A well-established bci paradigm uses signal power modulations of fast rhythmic brain activity. Such power modulations are linked to a broad variety of sensorimotor, cognitive and perceptual tasks, and feedback for the user can be provided by different sensory modalities, so we decided to investigate whether different sensory modalities of feedback might differently modulate the electroencephalography (eeg) during a bci task. Ten healthy volunteers performed bci motor imagery session while controlling a hand exoskeleton. Participants received feedback with different sensory modalities: visual, somatosensory (using a hand exoskeleton) or auditory. As expected, we found that cortical oscillations of eeg in beta frequencies were modulated by movements. Our main finding was that modulation of beta band in eeg was strongly increased by somatosensory feedback using the exoskeleton, a finding with important implications for design and implementation of bci experiments.