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Abstract: Previous studies have shown that using a tool modifies in a short time-scale both near-body space perception and arm-length representation in the body schema. However, to date no research has specifically investigated the effect of tool-use on an action-related perceptual task. We report here a study assessing the effect of tool-use on the perception of reachable space for perceptual estimates made in reference to either the tool or the hand. Using the tool on distal objects resulted in an extension of perceived reachable space with the tool and reduced the variability of reachability estimates. Tool use also extended perceived reachable space with the hand, but with a concomitant increase of the variability of reachability estimates. These findings suggest that tool incorporation into the represented arm following tool-use improves the anticipation of action possibilities with the tool, while hand representation becomes less accurate. [Copyright &y& Elsevier]

Target selection for action depends not only on the egocentric location of objects estimated from retinal and extraretinal variables, but also on the assessment of current action possibilities. In the present study, we investigated the effect of altering sensorimotor anticipation processes on subsequent perceptual estimates of reachability. To do so, we conducted two experiments in which we changed the relation between visual distance and movement amplitude. Experiment 1 showed that iterative visuomotor adaptation to distorted visual feedback (in steps of ±15 mm, up to a total adaptation of ±75 mm) led to a congruent variation of perceived reachable space, although the first introduction of the shifted visual feedback produced a reduction of perceived reachable space whatever the direction of the feedback shift. Experiment 2 showed that increasing uncertainty about visuomotor performances, by providing a visual feedback randomly shifted in depth (±7.5 mm), produced the same reduction of perceived reachable space in the absence of visuomotor adaptation. Taken together, these data suggest that the visual perception of reachable space depends on a motor-related perceptual system, which is affected by both visuomotor recalibration and reliability of the visuomotor system. [ABSTRACT FROM AUTHOR]

Background: Neuropsychological tests are particularly important for the clinical evaluation and Alzheimer's disease (AD) diagnosis. However, the tests currently employed for neuropsychological assessment have been developed several decades ago, and thus they do not fully exploit the potential provided by modern digital tools. One of the tests most commonly employed to assess attention and executive functions is the Trail Making Test (TMT).Objective: The aim of this study was to evaluate whether the TMT developed and used for the serious exergame X-Torp (TMTX-Torp) can be used to evaluate cognitive functions such as mental flexibility.Methods: Adjusted multivariate mixed model was used to compare performances in the TMTX-Torp to performances in the standard variant (TMTs) in three populations. 21 participants with AD (78.6y±8.5 y), 27 with mild cognitive impairment (MCI) (76.8y±8.5 y), and 27 healthy (HEC) (71.8y±7.4 y) were included.Results: A difference was observed for the TMT A between AD and HEC and for the TMT B between AD and MCI and between AD and HEC. Whatever the variant of the TMT, we found a positive linear correlation between the time to complete the TMTX-Torp and the TMTs for HEC (TMT A: r = 0.75, p < 0.001; TMT B: r = 0.52, p = 0.008) and MCI participants (TMT A: r = 0.53, p = 0.005; TMT B: r = 0.48, p = 0.025) but not for AD participants.Conclusion: Although these versions of the TMT were not identical, the results showed that both versions were able to discriminate between HEC, MCI, and AD populations. [ABSTRACT FROM AUTHOR]

Virtual Reality (VR) has emerged as a promising tool in many domains of therapy and rehabilitation, and has recently attracted the attention of researchers and clinicians working with elderly people with MCI, Alzheimer’s disease and related disorders. Here we present a study testing the feasibility of using highly realistic image-based rendered VR with patients with MCI and dementia. We designed an attentional task to train selective and sustained attention, and we tested a VR and a paper version of this task in a single-session within-subjects design. Results showed that participants with MCI and dementia reported to be highly satisfied and interested in the task, and they reported high feelings of security, low discomfort, anxiety and fatigue. In addition, participants reported a preference for the VR condition compared to the paper condition, even if the task was more difficult. Interestingly, apathetic participants showed a preference for the VR condition stronger than that of non-apathetic participants. These findings suggest that VR-based training can be considered as an interesting tool to improve adherence to cognitive training in elderly people with cognitive impairment. [ABSTRACT FROM AUTHOR]

Background: Computer vision combined with human annotation could offer a novel method for exploring facial expression (FE) dynamics in children with autism spectrum disorder (ASD). Methods: We recruited 157 children with typical development (TD) and 36 children with ASD in Paris and Nice to perform two experimental tasks to produce FEs with emotional valence. FEs were explored by judging ratings and by random forest (RF) classifiers. To do so, we located a set of 49 facial landmarks in the task videos, we generated a set of geometric and appearance features and we used RF classifiers to explore how children with ASD differed from TD children when producing FEs. Results: Using multivariate models including other factors known to predict FEs (age, gender, intellectual quotient, emotion subtype, cultural background), ratings from expert raters showed that children with ASD had more difficulty producing FEs than TD children. In addition, when we explored how RF classifiers performed, we found that classification tasks, except for those for sadness, were highly accurate and that RF classifiers needed more facial landmarks to achieve the best classification for children with ASD. Confusion matrices showed that when RF classifiers were tested in children with ASD, anger was often confounded with happiness. Limitations: The sample size of the group of children with ASD was lower than that of the group of TD children. By using several control calculations, we tried to compensate for this limitation. Conclusion: Children with ASD have more difficulty producing socially meaningful FEs. The computer vision methods we used to explore FE dynamics also highlight that the production of FEs in children with ASD carries more ambiguity. [ABSTRACT FROM AUTHOR]

Background: The use of Serious exerGames (SeG) as enriched environments (EE), which promotes cognitive simulation with physical activity in a positive emotional context, has been proposed to represent a powerful method to slow down the decline due to neurodegenerative diseases (ND), such as Alzheimer's disease (AD). However, so far, no SeG targeting EE has been tested in ND subjects.Objective: This study aimed at evaluating the usability and short-term training effects of X-Torp, an action SeG designed for elderly ND subjects with mild cognitive impairment (MCI) and AD.Methods: X-Torp is a SeG played using the Microsoft® Kinect™. 10 ND subjects and 8 healthy elderly controls (HEC) were enrolled in a 1-month program with three training sessions per week. Usability was evaluated through game time, game performance, the aerobic intensity level reached, perceived emotions, and perceived usability.Results: All participants successfully completed the training program. ND subjects played less and had a lower game performance compared to HEC. During the sessions, ND subjects maintained a light intensity of aerobic activity, while HEC maintained a moderate intensity. Both groups experienced only positive emotions, and reported a 'moderate' to 'high' perceived competence, a 'moderate' game difficulty, and a 'high' interest in the game.Conclusion: Usability results suggest that X-Torp represents a usable EE for healthy subjects and persons with MCI and AD. However, in order to reach moderate or high intensity of aerobic activity, X-Torp control modes should be adapted to become more physically stimulating. [ABSTRACT FROM AUTHOR]