Electrophysiological Correlates of Virtual-Reality Applications in the Rehabilitation Setting: New Perspectives for Stroke Patients

Here we reviewed the last evidence on the application of electroencephalography (EEG) as a non-invasive and portable neuroimaging method useful to extract hallmarks of neuroplasticity induced by virtual reality (VR) rehabilitation approaches in stroke patients. In the neurorehabilitation context, VR training has been used extensively to hamper the effects of motor treatments on the stroke’s brain. The concept underlying VR therapy is to improve brain plasticity by engaging users in multisensory training. In this narrative review, we present the key concepts of VR protocols applied to the rehabilitation of stroke patients and critically discuss challenges of EEG signal when applied as endophenotype to extract neurophysiological markers. When VR technology was applied to magnify the effects of treatments on motor recovery, significant EEG-related neural improvements were detected in the primary motor circuit either in terms of power spectral density or as time-frequency domains.

Multisensory balance training for unsteady elderly people: A scoping review

BACKGROUND: Posture control involves complex reactions of dynamic and static movements, and various sensory inputs. There is evidence that exercise using multisensory stimulation is moderately effective in improving the balance of the elderly. OBJECTIVE: The main purpose of this paper was to examine the existing literature to validate the effectiveness and applicability of multisensory stimulation training. METHODS: All relevant literature published as of June 1, 2020 in four prominent databases was searched (Embase, PubMed, PsycINFO, and Web of science) using the five-stage review framework proposed by Arksey and O’Malley. RESULTS: Multisensory stimulation training was more effective when vestibular and somatosensory were combined with visual stimuli, and differences in effectiveness compared to the effectiveness of existing treatments were confirmed. However, most of the reviewed papers are compared to simple strength training, and studies that compare the effects of multisensory stimulation training by setting a control group are still lacking. CONCLUSION: Further research is required to further elucidate the training conditions and treatment environment for multisensory training for the elderly at risk of falls and to provide strategies to improve treatment methods. In addition, a study that can evaluate user satisfaction in a way that best shows the treatment effect using qualitative research methods will be needed.

Emergence ofβandγnetworks following multisensory training

Our perceptual reality relies on inferences about the causal structure of the world given by multiple sensory inputs. In ecological settings, multisensory events that cohere in time and space benefit inferential processes: hearing and seeing a speaker enhances speech comprehension, and the acoustic changes of flapping wings naturally pace the motion of a flock of birds. Here, we asked how a few minutes of (multi)sensory training could shape cortical interactions in a subsequent perceptual task, and investigated oscillatory activity and functional connectivity as a function of sensory history in training. Human participants performed a visual motion coherence discrimination task while being recorded with magnetoencephalography (MEG). Three groups of participants performed the same task with visual stimuli only, while listening to acoustic textures temporally comodulated with the strength of visual motion coherence, or with auditory noise uncorrelated with visual motion. The functional connectivity patterns before and after training were contrasted to resting-state networks to assess the variability of common task-relevant networks, and the emergence of new functional inter-actions following training. One main finding is the emergence of a large-scale synchronization in the highγ(gamma: 60−120Hz) andβ(beta:15−30Hz) bands for individuals who underwent comodulated multisensory training. The post-training network involved prefrontal, parietal, and visual cortices. Our results suggest that the integration of evidence and decision-making strategies become more efficient following congruent multisensory training through plasticity in network routing and oscillatory regimes.