Immersive Virtual Environments and Wearable Haptic Devices in rehabilitation of children with neuromotor impairments: a single-blind randomized controlled crossover pilot study

Background: The past decade has seen the emergence of rehabilitation treatments using virtual reality. One of the advantages in using this technology is the potential to create positive motivation, by means of engaging environments and tasks shaped in the form of serious games. The aim of this study is to determine the efficacy of immersive Virtual Environments and weaRable hAptic devices (VERA) for rehabilitation of upper limb in children with Cerebral Palsy (CP) and Developmental Dyspraxia (DD). Methods: A two period cross-over design was adopted for determining the differences between the proposed therapy and a conventional treatment. Eight children were randomized into two groups: one group received the VERA treatment in the first period and the manual therapy in the second period, and viceversa for the other group. Children were assessed at the beginning and the end of each period through both the Nine Hole Peg Test (9-HPT, primary outcome) and Kinesiological Measurements obtained during the performing of similar tasks in a real setting scenario (secondary outcomes). Results: All subjects, not depending from which group they come from, significantly improved in both the performance of the 9-HPT and in the parameters of the kinesiological measurements (movement error and smoothness). No statistically significant differences have been found between the two groups. Conclusions: These findings suggest that immersive VE and wearable haptic devices is a viable alternative to conventional therapy for improving upper extremity function in children with neuromotor impairments. Trial registration ClinicalTrials, NCT03353623. Registered 27 November 2017-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03353623

Perplexity-free Parametric t-SNE

The t-distributed Stochastic Neighbor Embedding (t-SNE) algorithm is a ubiquitously employed dimensionality reduction (DR) method. Its non-parametric nature and impressive efficacy motivated its parametric extension. It is however bounded to a user-defined perplexity parameter, restricting its DR quality compared to recently developed multi-scale perplexity-free approaches. This paper hence proposes a multi-scale parametric t-SNE scheme, relieved from the perplexity tuning and with a deep neural network implementing the mapping. It produces reliable embeddings with out-of-sample extensions, competitive with the best perplexity adjustments in terms of neighborhood preservation on multiple data sets.Comment: ESANN 2020 proceedings, European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning. Online event, 2-4 October 2020, i6doc.com publ., ISBN 978-2-87587-074-2. Available from http://www.i6doc.com/en

Defective chromatic and achromatic visual pathways in developmental dyslexia : Cues for an integrated intervention programme

Purpose: As well as obtaining confirmation of the magnocellular system involvement in developmental dyslexia (DD); the aim was primarily to search for a possible involvement of the parvocellular system; and, furthermore, to complete the assessment of the visual chromatic axis by also analysing the koniocellular system. Methods: Visual evoked potentials (VEPs) in response to achromatic stimuli with low luminance contrast and low spatial frequency, and isoluminant red/green and blue/yellow stimuli with high spatial frequency were recorded in 10 dyslexic children and 10 age- and sex-matched, healthy subjects. Results: Dyslexic children showed delayed VEPs to both achromatic stimuli (magnocellular-dorsal stream) and isoluminant red/green and blue/yellow stimuli (parvocellular-ventral and koniocellular streams). To our knowledge, this is the first time that a dysfunction of colour vision has been brought to light in an objective way (i.e., by means of electrophysiological methods) in children with DD. Conclusion: These results give rise to speculation concerning the need for a putative approach for promoting both learning how to read and/or improving existing reading skills of children with or at risk of DD. The working hypothesis would be to combine two integrated interventions in a single programme aimed at fostering the function of both the magnocellular and the parvocellular streams

FADER: Fast adversarial example rejection

Deep neural networks are vulnerable to adversarial examples, i.e., carefully-crafted inputs that mislead classification at test time. Recent defenses have been shown to improve adversarial robustness by detecting anomalous deviations from legitimate training samples at different layer representations - a behavior normally exhibited by adversarial attacks. Despite technical differences, all aforementioned methods share a common backbone structure that we formalize and highlight in this contribution, as it can help in identifying promising research directions and drawbacks of existing methods. The first main contribution of this work is the review of these detection methods in the form of a unifying framework designed to accommodate both existing defenses and newer ones to come. In terms of drawbacks, the overmentioned defenses require comparing input samples against an oversized number of reference prototypes, possibly at different representation layers, dramatically worsening the test-time efficiency. Besides, such defenses are typically based on ensembling classifiers with heuristic methods, rather than optimizing the whole architecture in an end-to-end manner to better perform detection. As a second main contribution of this work, we introduce FADER, a novel technique for speeding up detection-based methods. FADER overcome the issues above by employing RBF networks as detectors: by fixing the number of required prototypes, the runtime complexity of adversarial examples detectors can be controlled. Our experiments outline up to 73× prototypes reduction compared to analyzed detectors for MNIST dataset, up to 50× for CIFAR10 dataset, and up to 82× on ImageNet10 dataset respectively, without sacrificing classification accuracy on both clean and adversarial data

Blink-related alfa and beta oscillations differentiate between minimally conscious state and unresponsive wakefulness syndrome/vegetative state

Recently, we have shown the existence of EEG delta blink-related oscillations (delta BROs), which are peculiar to the resting state of the healthy subject. The hypothesis is that they can represent the activation of updating and short-term memorization of the context, which are at the basis of the global (gestaltic) awareness of the visuo-spatial environment. As expected, the source of these oscillations was located in the precuneus, whose function is believed to be the surveillance of the internal and external environments and some assessment of salience of stimuli for the individual. In patients with disorders of consciousness (DOC), delta BROs were poorly represented, so that it was not possible to identify unambiguous and homogeneous sources. However, parameters such as power and phase synchronization of delta BROs was directly proportional to the levels of consciousness expressed by the Levels of Cognitive Functioning Scale (LCFS) scores. Nevertheless, at the group level, it was not possible to statistically distinguish minimally conscious state (MCS) from unresponsive wakefulness syndrome/vegetative state (UWS/VS). In an effort to increase our capabilities of differential diagnosis, and taking into account that brain responses are to be considered as the superposition of multiple oscillations, we have extended our analysis to other frequency ranges than delta. EEG activity at rest was recorded in 12 healthy subjects and 9 patients with DOC (5 MCS, and 4 UWS/VS). Three-second-lasting EEG epochs centred on each blink instance were analysed in both time- (BROs) and frequency-domains (event-related spectral perturbation or ERSP). Cortical sources of blink-related band power maxima were estimated by Sloreta. It was thus possible to obtain a statistically significant differentiation between MCS and UWS/VS on the basis of both alpha and beta oscillations within a time window of about 1000ms after the blink. The brain region that turned out to be more active in MCS with respect to UWS/VS was the precuneus (which was however still deficient compared to healthy subjects). The brain regions that turned out to be more active in MCS with respect to both healthy and UWS/VS subjects were the left temporo-parietal junction and, to some extent, the left prefrontal cortex.The activation of such a fronto-parieto-temporal network in MCS subjects could be interpreted as a compensatory mechanism to the current condition of functional insufficiency of the precuneus

CARATTERISTICHE CHINESIOLOGICHE DEL MOVIMENTO DI PUNTAMENTO IN PAZIENTI CON DISTONIA CERVICALE IDIOPATICA: DESCRIZIONE DI UNA CASISTICA

Si descrivono le caratteristiche cinematiche del movimento di puntamento in un campione di soggetti con distonia cervicale idiopatic

EEG correlates of action awareness in the parietal cortex

It is assumed that while performing a goal-oriented arm movement we anticipate feeling changes in our arm configuration that should correspond to the intention and to the motor command that produced the movement. The function of matching the predicted with the actual sensory consequences of a movement may not only help to adjust a given motor program but may also contribute to the feeling of our self as the agent of our own actions, that is the “sense of agency”. Current opinion is that this mismatch gains access to consciousness when discrepancies between the intended action and its perceived consequences, either visual or kinesthetic, reach a certain threshold. Beyond this limit, awareness of action discrepancy or a perturbed sense of agency appears. Various brain areas, especially the prefrontal and parietal, have been involved in such conscious monitoring by neuroimaging or inactivation studies, which, however, did not allow us to elucidate the operating mode of the engaged neural network/s nor the time course of the process. To evaluate at the level of brain rhythms the neural correlates of action awareness, we submitted six normal subjects to a 64 channel EEG recording during the execution of cued reaching movements from a starting point to a circumference under a variable degree of perturbation of the visual feedback. At this aim the output of an electromagnetic motion-tracking system, whose sensor was located on the subject right finger, was processed by a computer and projected on a mirror where the subjects saw their virtual finger as a cursor, having their hand hidden by the mirror. Computer processing used an algorithm for adding a linear directional bias in clockwise/counterclockwise direction of varying amplitudes or for producing a randomly-generated distortion (d). Thus, five experimental conditions were presented according to apseudorandom sequence: perfect (0 ° d) or no correspondence (randomly-generated distortion) between the actual and the seen movement, visual displacement of 7.5 ° or 18 ° which was respectively under or above the threshold for conscious detection and, finally, displacement at the threshold value (12.5 ° d) such that elicited conscious perception of distortion in approximately half movements. After each movement subjects gave their judgment whether visual feedback was congruent (C), distorted (D) or independent (other's, O) with respect to their actual movement. As expected, a discrepancy was detected in 4 ± 3%, 23 ± 15%, 52 ± 19% and 79 ± 11% of the 0 ° , 7.5 ° , 12.5 ° and 18 ° d movements, respectively. In all cases in which a randomly-generated distortion was applied, the movement was refused as self. The time-frequency EEG analysis demonstrated that at parietal sites movement-related β1 desynchronization was significantly higher in 18 ° d as compared to 0 ° and 7.5 ° d conditions. Accordingly, desynchronization was higher for movements scored as D as compared to C. In the case of O judgment, desynchronization in α3 and β1 frequency bands at parietal sites was not different from that associated with D judgment within the first 500 ms since the exit from the starting point, but, in contrast to D, it partially and sharply recovered towards pre-movement values in the following 1 s period though movement was still ongoing. Analysis of independent components is in progress in the attempt to localize the source/s of α/β desynchronization. Our data indicate that conscious monitoring of the discrepancies between predicted (and kinesthetically detected) and visually perceived consequences of an arm movement is associated with an increase of movement-related low beta desynchronization in the parietal cortex. We may speculate that in trials in which subjects become aware that visual feedback is not related to their own but instead to another's movement, the computational cost needed to incorporate/select afferent signals such as the incongruent visual and the veridical proprioceptive signals in the monitoring/matching process may decrease and this may lead to a partial recovery of beta rhythm

Utilizzo di un sistema di realtà virtuale immersiva e percezione aptica nella riabilitazione dell'arto superiore in bambini affetti da disabilità neuromotorie

si descrive un trattamento innovativo e altamente tecnologico delle disabilità dell'arto superiore nell'età evolutiv

Luminant and Chromatic VEPs in Dyslexic children: magnocellular or parvocellular dysfunction?

VEPs study in dyslexic childre

PROPOSTA DI UN PROTOCOLLO DI VALUTAZIONE DELLO SVILUPPO PRASSICO NELLA SECONDA INFANZIA: DATI PRELIMINARI.

Si descrive un nuovo protocollo per valutare le abilità prassiche del bambin