Fabbri-Destro, M. | bioRxiv Science

bioRxiv2026

A Virtual Reality Dataset to Support Hand Action Observation in Rehabilitation and Motor Learning Studies

The recovery of motor function is increasingly understood as a process influenced not only by physical training but also by perceptual and cognitive strategies. Action Observation Treatment (AOT), a neurorehabilitation approach in which patients observe goal-directed motor actions before executing them, has demonstrated clinical benefits; however, its wider implementation is hindered by a lack of standardized procedures. We present an open-access dataset of 33 upper limb gestures specifically developed to support the administration of Virtual Reality-based AOT (VR-AOT). The gestures were selected in collaboration with expert physiotherapists to ensure clinical relevance, and are provided as motion capture recordings along with Unity-based 3D animations embedded in configurable virtual scenes. The dataset is designed for flexibility, allowing users to modify parameters such as viewpoint, laterality, and repetition count. Technical validation confirms its usability and therapeutic applicability across multiple clinical and research contexts. This dataset offers a standardized yet customizable resource for developing and comparing VR-AOT protocols, with potential applications in neurorehabilitation and motor learning research.

neuroscience↗

bioRxiv2021

The value of corticospinal excitability and intracortical inhibition in predicting motor skill improvement driven by action observation

BACKGROUND AND OBJECTIVEAction observation can sustain motor skill improvement. At the neurophysiological level, action observation affects the excitability of the motor cortices, as measured by transcranial magnetic stimulation. However, whether the cortical modulations induced by action observation may explain the amount of motor improvement driven by action observation training (AOT) remains to be addressed. METHODSWe conducted a two-phase study involving 40 volunteers. First, we assessed the effect of action observation on corticospinal excitability (amplitude of motor evoked potentials), short-interval intracortical inhibition, and transcallosal inhibition (ipsilateral silent period). Subsequently, a randomized-controlled design was applied, with AOT participants asked to observe and then execute, as quickly as possible, a right-hand dexterity task six consecutive times, whereas controls had to observe a no-action video before performing the same task. RESULTSAOT participants showed greater performance improvement relative to controls. The amount of improvement in the AOT group was predicted by the amplitude of corticospinal modulation during action observation and even more by the amount of intracortical inhibition induced by action observation. Importantly, these relations were found specifically for the AOT group and not for the controls. CONCLUSIONSIn this study, we identified the neurophysiological signatures associated with, and potentially sustaining, the outcome of AOT. Intracortical inhibition driven by action observation plays a major role. These findings elucidate the cortical mechanisms underlying AOT efficacy and open to predictive assessments for the identification of potential responders to AOT, informing the rehabilitative treatment individualization.

neuroscience↗