ZORA robot to assist a caregiver in prospective memory tasks: A preliminary study.

The objective of the present study was to evaluate the interest of an assistance robot to help caregivers manage the activities of daily living of institutionalized elderly people with Alzheimer's disease. Twenty-three institutionalized persons (60% women; average age 89; average MMSE score of 20.8) with Alzheimer Disease (AD) were recruited and invited to participate in prospective memory exercise sessions, conducted either by a caregiver or by a robot (assisted by a caregiver). They were divided into two groups equivalent in age, level of education and MMSE score. In addition, the sessions were recorded in order to compare the interaction behaviors of the 2 groups, using a validated observation grid. The results showed that: 1) prospective memory tasks are better performed when offered by the caregiver; 2) when strong help linked to the recovery index is provided to perform the tasks, the robot or caregiver no longer show significant differences; 3) participants interact more with the caregiver than with the robot. Our results confirm that the use of companion robots is a promising way to help caregivers manage the daily activities of people with Alzheimer's. However, to optimize this assistance, further investigations should be conducted to improve the fluidity of interactions between the patient and the robot.

An interpretable machine learning approach to study the relationship beetwen retrognathia and skull anatomy.

Mandibular retrognathia (C2Rm) is one of the most common oral pathologies. Acquiring a better understanding of the points of impact of C2Rm on the entire skull is of major interest in the diagnosis, treatment, and management of this dysmorphism, but also permits us to contribute to the debate on the changes undergone by the shape of the skull during human evolution. However, conventional methods have some limits in meeting these challenges, insofar as they require defining in advance the structures to be studied, and identifying them using landmarks. In this context, our work aims to answer these questions using AI tools and, in particular, machine learning, with the objective of relaying these treatments automatically. We propose an innovative methodology coupling convolutional neural networks (CNNs) and interpretability algorithms. Applied to a set of radiographs classified into physiological versus pathological categories, our methodology made it possible to: discuss the structures impacted by retrognathia and already identified in literature; identify new structures of potential interest in medical terms; highlight the dynamic evolution of impacted structures according to the level of gravity of C2Rm; provide for insights into the evolution of human anatomy. Results were discussed in terms of the major interest of this approach in the field of orthodontics and, more generally, in the field of automated processing of medical images.

Estimation of Distances within Real and Virtual Dental Models as a Function of Task Complexity.

Orthodontists have seen their practices evolve from estimating distances on plaster models to estimating distances on non-immersive virtual models. However, if the estimation of distance using real models can generate errors (compared to the real distance measured using tools), which remains acceptable from a clinical point of view, is this also the case for distance estimation performed on digital models? To answer this question, 50 orthodontists (31 women and 19 men) with an average age of 36 years (σ = 12.84; min = 23; max = 63) participated in an experiment consisting of estimating 3 types of distances (mandibular crowding, inter-canine distance, and inter-molar distance) on 6 dental models, including 3 real and 3 virtual models. Moreover, these models were of three different levels of complexity (easy, medium, and difficult). The results showed that, overall, the distances were overestimated (compared to the distance measured using an instrument) regardless of the situation (estimates on real or virtual models), but this overestimation was greater for the virtual models than for the real models. In addition, the mental load associated with the estimation tasks was considered by practitioners to be greater for the estimation tasks performed virtually compared to the same tasks performed on plaster models. Finally, when the estimation task was more complex, the number of estimation errors decreased in both the real and virtual situations, which could be related to the greater number of therapeutic issues associated with more complex models.

Correction: Predicting Mental Imagery-Based BCI Performance from Personality, Cognitive Profile and Neurophysiological Patterns.

[This corrects the article DOI: 10.1371/journal.pone.0143962.].

Evaluation of a smart home platform for adults with Down syndrome.

People with Down syndrome (DS) encounter difficulties in their daily lives. In recent years, smart homes have provided some answers to the problem of residential autonomy. In fact, smart homes can provide support for complex routines and activities, while adjusting to the person's behaviors and needs and offering maximum control of the environment. In this context, the objectives of this study were to assess (i) the usability of the smart home platform as well as (ii) the impact of the use (for 6 months) of this platform by adults with DS on many dimensions such as residential autonomy, projection into the future, the development of a life plan, self-determination, quality of life, self-esteem, anxiety, and psychological well-being. The first objective of a preliminary study was to verify that the support platform we use is suitable and can be used effectively by people with DS. For the preliminary study, the evaluations show effective, satisfactory and efficient use of all applications. Regarding the objective of our study, the evaluations show positive impacts on many dimensions such as living skills, self-determination, quality of life, self-esteem, anxiety and certain components of life psychological well-being.

Real-time cognitive performance and positive symptom expression in schizophrenia.

Deficits in cognitive functions are frequent in schizophrenia and are often conceptualized as stable characteristics of this disorder. However, cognitive capacities may fluctuate over the course of a day and it is unknown if such variation may be linked to the dynamic expression of psychotic symptoms. This investigation used Ecological Momentary Assessment (EMA) to provide mobile tests of cognitive functions and positive symptoms in real time. Thirty-three individuals with schizophrenia completed five EMA assessments per day for a one-week period that included real-time assessments of cognitive performance and psychotic symptoms. A subsample of patients and 31 healthy controls also completed a functional MRI examination. Relative to each individual's average score, moments of worsened cognitive performance on the mobile tests were associated with an increased probability of positive symptom occurrence over subsequent hours of the day (coef = 0.06, p < 0.05), adjusting for the presence of psychotic symptoms at the moment of mobile test administration. These prospective associations varied as a function of graph theory indices in MRI analyses. These findings demonstrate that cognitive performance is prospectively linked to psychotic symptom expression in daily life, and that underlying brain markers may be observed in the Executive Control Network. While the potential causal nature of this association remains to be investigated, our results offer promising prospects for a better understanding of the underlying mechanisms of symptom expression in schizophrenia.

Prospective memory in adults with down syndrome.

Prospective memory (PM) refers to the ability to remember one's intentions (what I must do), at the appropriate time, in the future (when I must do it). The objective of this work is to study the performance of people with Down syndrome (DS) compared to two control groups, matched by mental age and chronological age. For this purpose, an adapted version of the virtual week, which is an ecological test to simulate the functioning of PM in everyday life, was used. The results suggest that people with DS have difficulties in PM that mainly concern the binding (association) between prospective (when to do) and retrospective (what to do) components. Moreover, people with DS perform better in PM when the task is repeated and time-based. These results are discussed in light of studies conducted with other populations.

A review of user training methods in brain computer interfaces based on mental tasks.

Mental-tasks based brain-computer interfaces (MT-BCIs) allow their users to interact with an external device solely by using brain signals produced through mental tasks. While MT-BCIs are promising for many applications, they are still barely used outside laboratories due to their lack of reliability. MT-BCIs require their users to develop the ability to self-regulate specific brain signals. However, the human learning process to control a BCI is still relatively poorly understood and how to optimally train this ability is currently under investigation. Despite their promises and achievements, traditional training programs have been shown to be sub-optimal and could be further improved. In order to optimize user training and improve BCI performance, human factors should be taken into account. An interdisciplinary approach should be adopted to provide learners with appropriate and/or adaptive training. In this article, we provide an overview of existing methods for MT-BCI user training-notably in terms of environment, instructions, feedback and exercises. We present a categorization and taxonomy of these training approaches, provide guidelines on how to choose the best methods and identify open challenges and perspectives to further improve MT-BCI user training.

[The digital workflow at the service of the practitioner's clinical learning] / Le workflow numérique au service de l'apprentissage clinique du praticien.

Our relationship to digital technologies will be a determining factor in building our identity as 21st century orthodontists. The digital workflow used in orthodontics can be summarized in four successive phases: diagnosis, treatment planning, computer Aid Manufacturing, therapeutic follow-up. According to Professor Stanislas Dehaene, cognitive neuroscience has identified four criteria on which learning success depends. Attention, active engagement, feedback and consolidation. Our article demonstrates that a good organization of the digital workflow, thought upstream and coherent, allows the practitioner to strengthen his learning from each treated clinical case by potentiating the four criteria of learning. This design which is a real challenge is part of an increase strategy.

Why we should systematically assess, control and report somatosensory impairments in BCI-based motor rehabilitation after stroke studies.

The neuronal loss resulting from stroke forces 80% of the patients to undergo motor rehabilitation, for which Brain-Computer Interfaces (BCIs) and NeuroFeedback (NF) can be used. During the rehabilitation, when patients attempt or imagine performing a movement, BCIs/NF provide them with a synchronized sensory (e.g., tactile) feedback based on their sensorimotor-related brain activity that aims at fostering brain plasticity and motor recovery. The co-activation of ascending (i.e., somatosensory) and descending (i.e., motor) networks indeed enables significant functional motor improvement, together with significant sensorimotor-related neurophysiological changes. Somatosensory abilities are essential for patients to perceive the feedback provided by the BCI system. Thus, somatosensory impairments may significantly alter the efficiency of BCI-based motor rehabilitation. In order to precisely understand and assess the impact of somatosensory impairments, we first review the literature on post-stroke BCI-based motor rehabilitation (14 randomized clinical trials). We show that despite the central role that somatosensory abilities play on BCI-based motor rehabilitation post-stroke, the latter are rarely reported and used as inclusion/exclusion criteria in the literature on the matter. We then argue that somatosensory abilities have repeatedly been shown to influence the motor rehabilitation outcome, in general. This stresses the importance of also considering them and reporting them in the literature in BCI-based rehabilitation after stroke, especially since half of post-stroke patients suffer from somatosensory impairments. We argue that somatosensory abilities should systematically be assessed, controlled and reported if we want to precisely assess the influence they have on BCI efficiency. Not doing so could result in the misinterpretation of reported results, while doing so could improve (1) our understanding of the mechanisms underlying motor recovery (2) our ability to adapt the therapy to the patients' impairments and (3) our comprehension of the between-subject and between-study variability of therapeutic outcomes mentioned in the literature.

Role of cognitive resources on everyday functioning among oldest-old physically frail.

BACKGROUND: Everyday functioning becomes a challenge with aging, particularly among frail oldest-old adults. Several factors have been identified as influencing everyday activities realization, including physical and cognitive functioning. However, the influence of cognitive resources as a compensatory factor in the context of physical frailty deserves further consideration. AIMS: This study aims to investigate in older adults physically frail the possible compensatory role of cognitive resources to perform everyday tasks. METHODS: Two groups of community-dwelling old participants (n = 26 per group) matched for their age and cognitive resources, have been drawn according to their level of physical functioning. Two measures of everyday functioning have been assessed: one self-reported by the participant (the IADL scale) and one performance-based measure (the TIADL tasks). RESULTS: Participants performed equally the TIADL tasks irrespective of their physical condition. Contrariwise, participants with low physical functioning reported more everyday difficulties than their counterparts with a high level of physical functioning. Additionally, regressions analyses revealed differential influence of cognitive resources on performance and reported measures of everyday functioning. DISCUSSION: Our data suggests that cognitive resources are more strongly involved in the performance-based IADL measure in situation of physical frailty. Additionally, for participants with low physical functioning, lower cognitive resources are associated with more perceived difficulties in everyday life. CONCLUSION: These results highlight the compensatory role of cognitive resources in physically frail older adults, and suggest that an overestimation of everyday difficulties compared to performance on IADL tasks is an early indicator of physical decline and cognitive compensation.

Navigation strategy in macaque monkeys: An exploratory experiment in virtual reality.

BACKGROUND: Spatial memory and navigation have been widely studied using animal models, most of them were performed with rodents and only few of them with non-human primates. Also, most of these studies were achieved in simple and small-scale mazes. NEW METHOD: In order to test navigation strategy in macaque monkeys, we used a double-cross virtual maze in which they could freely move using a joystick and a procedure adapted from previous studies with rodents. The monkeys had first to learn several routes from a specific starting point to reach separate positions, each one containing distinct symbols, and then to associate each route with these symbols. After this phase, the monkeys had to reach these targets from a second starting point positioned at the other end of the maze, requiring the use an allocentric strategy. In order to evaluate monkey's strategy, we analyzed monkey's first choice as a function of the symbol presented. RESULTS: The monkeys were able to learn routes and to associate routes with symbols but were not able to use an allocentric strategy. They also did not use the procedural strategy and seemed disoriented or adopted a stereotypical behavior. COMPARISON WITH EXISTING METHOD(S): Contrary to the few studies using small-scale environments, the monkeys seemed unable to solve the allocentric task. The studies using virtual mazes seemed not to specifically analyze monkey's navigation strategy. CONCLUSIONS: Supplementary experiments will be necessary to explain the origin of the monkey's inability to use an allocentric strategy. Modified learning conditions could also incite the monkeys to develop an allocentric representation.

Wayfinding in a virtual environment and Down syndrome: The impact of navigational aids.

OBJECTIVE: Individuals with intellectual disabilities (ID), such as those with Down syndrome (DS), sometimes get lost, even when walking familiar routes. Among the spatial cognition models addressing the dynamic construction of spatial representations, the theoretical framework of Siegel and White (1975) remains a reference. The aim of this work is to use virtual reality technology to (a) elucidate the spatial deficits associated with ID in reference to the Siegel and White framework and (b) to evaluate the effectiveness of 3 wayfinding assistive procedures (signified landmarks, arrows, and elevated views). METHOD: We have developed a virtual environment that represents a replica of the district near Bordeaux hospital, by using Virtools software. The subject is instructed to learn a path and reproduce it by using a joystick. Four experimental learning conditions were compared. The participant observed the path either from ground level without support ("control" condition), or with direction support ("arrows" condition), or with landmark support ("signified landmarks" conditions) or from a height of 4 m in the "elevated view" condition. RESULTS: The results revealed that DS participants achieved significantly lower scores than typically developing children for the wayfinding, route level, and configurational level tasks. The performance of DS participants was enhanced only in the signified landmarks condition (condition in which the landmark had a bright color). CONCLUSION: Such results may be particularly fruitful to define appropriate digital aids to support people with DS to travel more independently in unfamiliar environments. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Are visual cues helpful for virtual spatial navigation and spatial memory in patients with mild cognitive impairment or Alzheimer's disease?

OBJECTIVE: To evaluate whether visual cues are helpful for virtual spatial navigation and memory in Alzheimer's disease (AD) and patients with mild cognitive impairment (MCI). METHOD: 20 patients with AD, 18 patients with MCI and 20 age-matched healthy controls (HC) were included. Participants had to actively reproduce a path that included 5 intersections with one landmark at each intersection that they had seen previously during a learning phase. Three cueing conditions for navigation were offered: salient landmarks, directional arrows and a map. A path without additional visual stimuli served as control condition. Navigation time and number of trajectory mistakes were recorded. RESULTS: With the presence of directional arrows, no significant difference was found between groups concerning the number of trajectory mistakes and navigation time. The number of trajectory mistakes did not differ significantly between patients with AD and patients with MCI on the path with arrows, the path with salient landmarks and the path with a map. There were significant correlations between the number of trajectory mistakes under the arrow condition and executive tests, and between the number of trajectory mistakes under the salient landmark condition and memory tests. CONCLUSION: Visual cueing such as directional arrows and salient landmarks appears helpful for spatial navigation and memory tasks in patients with AD and patients with MCI. This study opens new research avenues for neuro-rehabilitation, such as the use of augmented reality in real-life settings to support the navigational capabilities of patients with MCI and patients with AD. (PsycINFO Database Record

Analysis of how people with intellectual disabilities organize information using computerized guidance.

Access to residential settings for people with intellectual disabilities (ID) contributes to their social participation, but presents particular challenges. Assistive technologies can help people perform activities of daily living. However, the majority of the computerized solutions offered use guidance modes with a fixed, unchanging sequencing that leaves little room for self-determination to emerge. The objective of the project was to develop a flexible guidance mode and to test it with participants, to describe their information organization methods. This research used a descriptive exploratory design and conducted a comparison between five participants with ID and five participants with no ID. The results showed a difference in the information organization methods for both categories of participants. The people with ID used more diversified organization methods (categorical, schematic, action-directed) than the neurotypical participants (visual, action-directed). These organization methods varied depending on the people, but also on the characteristics of the requested task. Furthermore, several people with ID presented difficulties when switching from virtual to real mode. These results demonstrate the importance of developing flexible guidance modes adapted to the users' cognitive strategies, to maximize their benefits. Studies using experimental designs will have to be conducted to determine the impacts of more-flexible guidance modes Implications for rehabilitation Intervention approaches favouring, self-determination, decision making, action analysis and results anticipation must be promoted with people with intellectual disabilities. Fixed and rigid technological guidance mode, like those currently favoured in interventions, is appropriate for only some people's profiles or may depend on the nature of the task. It seems that people with ID use a wide spectrum of organization strategies and that adapting guidance modes to all these strategies is relevant.

Age and active navigation effects on episodic memory: A virtual reality study.

We investigated the navigation-related age effects on learning, proactive interference semantic clustering, recognition hits, and false recognitions in a naturalistic situation using a virtual apartment-based task. We also examined the neuropsychological correlates (executive functioning [EF] and episodic memory) of navigation-related age effects on memory. Younger and older adults either actively navigated or passively followed the computer-guided tour of an apartment. The results indicated that active navigation increased recognition hits compared with passive navigation, but it did not influence other memory measures (learning, proactive interference, and semantic clustering) to a similar extent in either age group. Furthermore, active navigation helped to reduce false recognitions in younger adults but increased those made by older adults. This differential effect of active navigation for younger and older adults was accounted for by EF score. Like for the subject-performed task effects, the effects from the navigation manipulation were well accounted for by item-specific/relational processing distinction, and they were also consistent with a source monitoring deficit in older adults.

Everyday-like memory for objects in ageing and Alzheimer's disease assessed in a visually complex environment: The role of executive functioning and episodic memory.

To investigate everyday memory, more and more studies rely on virtual-reality applications to bridge the gap between in situ approaches and laboratory settings. In this vein, the present study was designed to assess everyday-like memory from the virtual reality-based Human Object Memory for Everyday Scenes (HOMES) test (Sauzéon et al., , Exp. Psychol., 59, 99) in ageing and in Alzheimer's disease (AD). Two aims motivated this study: the first was to assess multiple processes of episodic memory (EM) functioning embedded within contexts closely related to real life in ageing and AD using the multi-trial free-recall paradigm, and the second aim was to evaluate the mediating effects of executive functioning (EF), EM, and subjective memory complaints (SMCs) on age differences in the HOMES measures and in AD. To this end, the HOMES test and neurocognitive tests of EF and EM were administered to 23 younger adults, 23 older adults, and 16 patients with AD. The results were: firstly, compared to young adults, elderly adults presented only free-recall decline that almost disappeared in recognition condition whereas AD patients exhibited a poor clustering, learning, and recognition performance, and also a high amount of false recognition; secondly, age differences as well as AD related deficits on the HOMES test were mediated by both memory and EF measure while those observed on false memory indices were only mediated by EM measure; thirdly, the HOMES indices are related to SMCs even when episodic or EF measures are controlled. Overall, the results supported the fact that the VR-based memory test is an appropriate device to capture age-related differences as well as the AD effect with respect to both in situ and laboratory settings.

Predicting Mental Imagery-Based BCI Performance from Personality, Cognitive Profile and Neurophysiological Patterns.

Mental-Imagery based Brain-Computer Interfaces (MI-BCIs) allow their users to send commands to a computer using their brain-activity alone (typically measured by ElectroEncephaloGraphy-EEG), which is processed while they perform specific mental tasks. While very promising, MI-BCIs remain barely used outside laboratories because of the difficulty encountered by users to control them. Indeed, although some users obtain good control performances after training, a substantial proportion remains unable to reliably control an MI-BCI. This huge variability in user-performance led the community to look for predictors of MI-BCI control ability. However, these predictors were only explored for motor-imagery based BCIs, and mostly for a single training session per subject. In this study, 18 participants were instructed to learn to control an EEG-based MI-BCI by performing 3 MI-tasks, 2 of which were non-motor tasks, across 6 training sessions, on 6 different days. Relationships between the participants' BCI control performances and their personality, cognitive profile and neurophysiological markers were explored. While no relevant relationships with neurophysiological markers were found, strong correlations between MI-BCI performances and mental-rotation scores (reflecting spatial abilities) were revealed. Also, a predictive model of MI-BCI performance based on psychometric questionnaire scores was proposed. A leave-one-subject-out cross validation process revealed the stability and reliability of this model: it enabled to predict participants' performance with a mean error of less than 3 points. This study determined how users' profiles impact their MI-BCI control ability and thus clears the way for designing novel MI-BCI training protocols, adapted to the profile of each user.

Age-Related Differences and Cognitive Correlates of Self-Reported and Direct Navigation Performance: The Effect of Real and Virtual Test Conditions Manipulation.

The present study investigated the effect of aging on direct navigation measures and self-reported ones according to the real-virtual test manipulation. Navigation (wayfinding tasks) and spatial memory (paper-pencil tasks) performances, obtained either in real-world or in virtual-laboratory test conditions, were compared between young (n = 32) and older (n = 32) adults who had self-rated their everyday navigation behavior (SBSOD scale). Real age-related differences were observed in navigation tasks as well as in paper-pencil tasks, which investigated spatial learning relative to the distinction between survey-route knowledge. The manipulation of test conditions (real vs. virtual) did not change these age-related differences, which are mostly explained by age-related decline in both spatial abilities and executive functioning (measured with neuropsychological tests). In contrast, elderly adults did not differ from young adults in their self-reporting relative to everyday navigation, suggesting some underestimation of navigation difficulties by elderly adults. Also, spatial abilities in young participants had a mediating effect on the relations between actual and self-reported navigation performance, but not for older participants. So, it is assumed that the older adults carried out the navigation task with fewer available spatial abilities compared to young adults, resulting in inaccurate self-estimates.

Age-related wayfinding differences in real large-scale environments: detrimental motor control effects during spatial learning are mediated by executive decline?

The aim of this study was to evaluate motor control activity (active vs. passive condition) with regards to wayfinding and spatial learning difficulties in large-scale spaces for older adults. We compared virtual reality (VR)-based wayfinding and spatial memory (survey and route knowledge) performances between 30 younger and 30 older adults. A significant effect of age was obtained on the wayfinding performances but not on the spatial memory performances. Specifically, the active condition deteriorated the survey measure in all of the participants and increased the age-related differences in the wayfinding performances. Importantly, the age-related differences in the wayfinding performances, after an active condition, were further mediated by the executive measures. All of the results relative to a detrimental effect of motor activity are discussed in terms of a dual task effect as well as executive decline associated with aging.