The advent of mixed reality (MR) systems has revolutionized human–computer interactions by seamlessly integrating virtual elements with the real world. Devices like the HoloLens 2 (HL2) enable intuitive, hands-free interactions through advanced hand-tracking technology, making them valuable in fields such as education, healthcare, engineering, and training simulations. However, despite the growing adoption of MR, there is a noticeable lack of comprehensive comparisons between the hand-tracking accuracy of the HL2 and high-precision benchmarks like motion capture systems. Such evaluations are essential to assess the reliability of MR interactions, identify potential tracking limitations, and improve the overall precision of hand-based input in immersive applications. This study aims to assess the accuracy of HL2 in tracking hand position and measuring kinematic hand parameters, including joint angles and lateral pinch span (distance between thumb and index fingertips), using its tracking data. To achieve this, the Vicon motion capture system (VM) was used as a gold-standard reference. Three tasks were designed: (1) finger tracing of a 2D pattern in 3D space, (2) grasping various common objects, and (3) lateral pinching of objects with varying sizes. Task 1 tests fingertip tracking, Task 2 evaluates joint angle accuracy, and Task 3 examines the accuracy of pinch span measurement. In all tasks, HL2 and VM simultaneously recorded hand positions and movements. The data captured in Task 1 were analyzed to evaluate HL2’s hand-tracking capabilities against VM. Finger rotation angles from Task 2 and lateral pinch span from Task 3 were then used to assess HL2’s accuracy compared to VM. The results indicate that the HL2 exhibits millimeter-level errors compared to Vicon’s tracking system in Task 1, spanning in a range from 2 mm to 4 mm, suggesting that HL2’s hand-tracking system demonstrates good accuracy. Additionally, the reconstructed grasping positions in Task 2 from both systems show a strong correlation and an average error of 5°, while in Task 3, the accuracy of the HL2 is comparable to that of VM, improving performance as the object thickness increases.

Background: Eye-tracking (ET) devices are gaining attention in technology-based paediatric rehabilitation through their intrinsic ability to assess patients’ engagement and visual attention within motivating, technology-based environments. We conducted a systematic review of available evidence from 2004 to 2025 on the implementation of ET in rehabilitative trainings targeting paediatric populations with neurological and neurodevelopmental disorders. This paper aims to outline the rehabilitative outcomes pursued in the clinical populations considered. Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three electronic databases (PubMed, Web of Science, and Scopus) were consulted to summarise the state of the art of the last 20 years. Selected articles were categorised according to the type of treated disorder and the rehabilitated function. Results: ET devices have been increasingly integrated into paediatric rehabilitation with promising results across multiple neurodevelopmental conditions (e.g., ASD, ADHD, cerebral palsy). These systems have proven effective not only in training gaze control, but also in enhancing executive functions, social cognition, communication, and participation. Furthermore, they promote personalised and data-driven solutions and support high levels of engagement, feasibility, and user satisfaction. Conclusions: ET represents a promising frontier for paediatric rehabilitation, addressing various neurodevelopmental disorders. The gaze-contingent protocols employed have demonstrated potential effects in promoting adaptive behaviour across multiple developmental areas. Further research is warranted to provide shared guidance and to strengthen practice recommendations.

The ability to move independently enables children to develop perceptual, cognitive, and social interaction skills. Concerning this, vision holds a key role. As a result, children with visual impairment (VI) might be more challenged in their ability to move within their surroundings and interact with their caregivers. This study investigated whether the use of multisensory stimuli could influence the motor exploration of children with VI and shape their interaction with the caregivers. For this, the present work examined the variability of children's motor trajectory and the distance between children and caregivers in a setting with and without multisensory cues. A Motion Capture System was used within an ecological playroom environment. The Strange Situation paradigm was simplified and adapted by placing three TechARMs in the corners of the playroom to deliver audio-visual stimuli, used instead of the stranger. Children with VI showed larger variability within their motor trajectory and kept a shorter distance from the caregivers when multisensory cues were introduced in the playroom. Multisensory signals were considered unusual and influenced the kinematic parameters. Motor control of the environment was achieved by managing attention flexibility. WHAT DOES THIS PAPER ADD?: This study enriches available evidence about the study of motor and social interaction in children with VI, highlighting how multisensory stimuli could either support or hinder social and motor behaviors. Moreover, enhancing ecological validity could drive progress in the development and application of technological devices to clinical and research setting.

Attentional resources are crucial in determining whether and how a specific stimulus is selected for further processing from a multitude of concurrent inputs. Within this framework, multisensory integration enhances the salience of environmental stimuli amplifying perceptual responses to events. According to the race model, competition among sensory modalities in multisensory stimulation resembles a race; thus, when bimodal or trimodal stimulation elicits faster responses compared to unimodal stimulation, the model's prediction is violated. The present study aimed to validate a technological device capable of delivering unimodal, bimodal and trimodal stimulation, and to investigate perceptual processes and attentional dynamics by applying the race model to multisensory data, utilizing a previous multisensory attentional paradigm. Our findings provide compelling evidence of facilitatory attentional capture by multisensory events, as reflected in faster detection times compared to unisensory stimuli. Notably, this advantage is most pronounced in the initial segment of the cumulative distribution function, where responses are less influenced by higher cognitive mechanisms. Additionally, manipulation of perceptual load created an interfering effect in preliminary analyses, not found within the race model. The Tech-PAD proves to be a valuable tool for replicating and expanding research paradigms. The results reinforce previous findings and extend the multisensory advantage to the trimodal condition, including the tactile modality. Furthermore, this study highlights the role of attentional control mechanisms in multisensory environments, particularly in the early stages of sensory perception. The findings are interpreted in relation to attentional mechanisms and cognitively efficient strategies, offering new insights into the optimization of sensory processing.

Postural control relies on the integration of visual, vestibular, proprioceptive, and auditory inputs to maintain stability. While previous studies have explored the effects of individual sensory modalities, the combined influence of multisensory disruptions on postural predictability remains unclear. We preliminary assessed postural behavior during quiet standing under manipulated sensory conditions in healthy participants. Eight adults stood barefoot on a Wii Balance Board, wearing a mixed reality headset with headphones and receiving vibrotactile stimulation to the Achilles tendons. Experimental conditions combined vibrotactile, static, or moving auditory stimuli across three visual states (Eyes Open, Eyes Closed, Blurred Vision). Center of pressure (CoP) in anterior-posterior (AP) and medio-lateral (ML) planes was collected and analyzed for signal predictability using Sample Entropy. The same experimental procedures were simulated by a biologically inspired neural mass model to investigate multisensory integration in postural control at the neural level. Behaviorally, proprioceptive perturbation via Achilles tendon vibration significantly increased Sample Entropy in both spatial planes, indicating reduced system predictability, while blurred vision decreased only in the AP plane, suggesting less flexible postural dynamics. The neural model replicated key behavioral trends and also revealed distinct central mechanisms underlying sensory interactions: while auditory inputs had minimal behavioral effects, at the simulated neural level, they increased Sample Entropy, especially under dynamic conditions. This revealed subtle modulation of predictability from auditory cues, which was not detectable at the behavioral level. These preliminary results highlight the modality-specific contributions to postural control and demonstrate the utility of Sample Entropy as measure of predictability, with our computational modeling uncovering, for the first time to our knowledge, neural integration processes related to multisensory integration and postural control predictability.