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This study assessed the impact of sex and typical aging on visuospatial working memory (VSWM), mental rotations, and navigational strategies using behavioral information. Fifty healthy participants regrouped in older (OA) and young adults (YA) performed the Walking Corsi test (WalCT) and the Redrawn Mental Rotation Test (MRT) to explore mental rotation abilities. We recorded kinematic data such as locomotion trajectories, and spatial orientations during navigation. We created a new method of data analysis for the WalCT performances and compared it with the classical approach. This original method allowed us to identify cognitive strategies based on errors analysis. Our data suggested that VSWM and mental rotation capacities in locomotion were modulated by age (YA scored higher than OA), and sex (Young Adult Males (YA-M) having higher performance than Young Adult Females (YA-F). We observed a preferential use of cognitive strategies related to sex; YA-F relied more on egocentric strategies whereas YA-M relied more on allocentric strategies. The preferential use of cognitive strategies in the YA group was not observed in the OA group producing more random errors per sequence. The results suggest the effects that age and sex have on VSWM, cognitive strategies, and mental rotation during navigation and highlight the importance of navigational strategies training.

The study of human behaviors in cognitive sciences provides clues to understand and describe people’s personal and interpersonal functioning. In particular, the temporal analysis of behavioral dynamics can be a powerful tool to reveal events, correlations and causalities but also to discover abnormal behaviors. However, the annotation of these dynamics can be expensive in terms of temporal and human resources. To tackle this challenge, this paper proposes a methodology to semi-automatically annotate behavioral data. Behavioral dynamics can be expressed as sequences of simple dynamical processes: transitions between such processes are generally known as change-points. This paper describes the necessary steps to detect and classify change-points in behavioral data by using a dataset collected in a real use-case scenario. This dataset includes motor observations from children with typical development and with neuro-developmental disorders. Abnormal movements which are present in such disorders are useful to validate the system in conditions that are challenging even for experienced annotators. Results show that the system: can be effective in the semi-automated annotation task; can be efficient in presence of abnormal behaviors; may achieve good performance when trained with limited manually annotated data.

In this paper, we use computational tools (Cipresso P, Matic, A, Giakoumis D, Ostrovsky Y (2015) Advances in computational psychometrics. Comput Math Methods Med. Article ID 418683. https://doi.org/10.1155/2015/418683.5) to explore human navigation through an example of a visuomotor spatial memory locomotor task, the Walking Corsi task (WCT) variant from a well-known table test known as the Corsi Block Tapping task [(CBT) [2] and [15]. This variant was performed using the “Virtual Carpet” ™ experimental setup. The subjects had to memorize a succession of the position of targets projected on the ground and reproduce sequences of 2 to 9 targets by walking to each. The trajectory of the head was recorded and processed from a kinematic point of view. Generic tools that computational data analytics provides and through computer simulations by replicating visually this data allowed categorization of the different features of the behavior of the subjects providing a new powerful tool for both normal and pathological behavior characterization.

Throughout this study, we employed unsupervised machine learning clustering algorithms, namely K-Means [1] and hierarchical agglomerative clustering (HAC) [2], to explore human locomotion and wayfinding using a VR Magic Carpet (VMC) [3], a table test version known as the Corsi Block Tapping task (CBT) [4]. This variation was carried out in the context of a virtual reality experimental setup. The participants were required to memorize a sequence of target positions projected on the rug and walk to each target figuring in the displayed sequence. the participant’s trajectory was collected and analyzed from a kinematic perspective. An earlier study [5] identified three different categories, but the classification remained ambiguous, implying that they include both kinds of individuals (normal and patients with cognitive spatial impairments). On this basis, we utilized K-Means and HAC to distinguish the navigation behavior of patients from normal individuals, emphasizing the most important discrepancies and then delving deeper to gain more insights.

International audience; To determine whether the growing ability to take a third-person perspective (3PP) is explained in part by the growing ability to inhibit a first-person perspective (1PP), 10-year-old children (n = 49) and 22-year-old adults (n = 52) performed a negative priming adaptation of the own body transformation task. Both children and adults were less efficient in adopting a 1PP after they adopted a 3PP-with a smaller amplitude of the negative priming effect with older age-and adults' and children's performances in the own body transformation task were predicted in part by their Stroop interference scores. These results suggest that the growing efficiency to adopt a 3PP is rooted in part in the growing efficiency to inhibit the 1PP.

Introduction De nombreux facteurs tels que l’âge, le genre ou l’education influencent les performances de memoire de travail dans des espaces proches et lointains. La litterature montre que les femmes utilisent preferentiellement une strategie dite egocentrique, tandis que les hommes utilisent une strategie dite allocentrique. L’objectif est d’etudier l’effet du genre sur les performances de memoire de travail visuospatiale et sur les strategies utilisees dans des espaces (proche vs lointain) et environnements (avec vs sans reperes visuels) differents. Materiel et methodes Quatre-vingt-deux etudiants (53F, 29H), 23 (± 3) ans ont realise deux tests de memoire de travail, l’un dans un environnement sans reperes visuels (test de Corsi) et l’autre dans un environnement avec reperes visuels (test du salon). Ces deux tests sont proposes dans un espace proche sur ordinateur et dans un espace lointain, i.e., navigation, a l’aide d’un « tapis virtuel ». Nous avons utilise des systemes d’eye-tracking (Tobii Glasses 2 et barre X2-30) pour analyser les strategies. Les variables retenues sont l’empan, le nombre et la duree des fixations et des saccades. Resultats Les performances sont meilleures dans l’espace proche que dans l’espace lointain (p Discussion/Conclusion Le genre a un effet sur les capacites de memoire de travail dans des espaces navigues qui semblent dependre des strategies utilisees.

During locomotion, a top-down organization has been previously demonstrated with the head as a stabilized platform and gaze anticipating the horizontal direction of the trajectory. However, the quantitative assessment of the anticipatory sequence from gaze to trajectory and body segments has not been documented. The present paper provides a detailed investigation into the spatial and temporal anticipatory relationships among the direction of gaze and body segments during locomotion. Participants had to walk along several mentally simulated complex trajectories, without any visual cues indicating the trajectory to follow. The trajectory shapes were presented to the participants on a sheet of paper. Our study includes an analysis of the relationships between horizontal gaze anticipatory behavior direction and the upcoming changes in the trajectory. Our findings confirm the following: 1) The hierarchical ordered organization of gaze and body segment orientations during complex trajectories and free locomotion. Gaze direction anticipates the head orientation, and head orientation anticipates reorientation of the other body segments. 2) The influence of the curvature of the trajectory and constraints of the tasks on the temporal and spatial relationships between gaze and the body segments: Increased curvature resulted in increased time and spatial anticipation. 3) A different sequence of gaze movements at inflection points where gaze plans a much later segment of the trajectory.

None of the previous studies on aging have tested the influence of action with respect to the degree of interaction with the environment (active or passive navigation) and the source of itinerary choice (self or externally imposed), on episodic memory encoding. The aim of this pilot study was to explore the influence of these factors on feature binding (the association between what, where and when) in episodic memory and on the subjective sense of remembering. Navigation in a virtual city was performed by 64 young and 64 older adults in one of four modes of exploration: (1) passive condition where participants were immersed as passengers of a virtual car (no interaction, no itinerary control), (2) itinerary control (the subject chose the itinerary, but did not drive the car), (3) low or (4) high navigation control (the subject just moved the car on rails or drove the car with a steering wheel and a gas pedal on a fixed itinerary, respectively). The task was to memorize as many events encountered in the virtual environment as possible along with their factual (what), spatial (where), and temporal (when) details, and then to perform immediate and delayed memory tests. An age-related decline was evidenced for immediate and delayed feature binding. Compared to passive and high navigation conditions, and regardless of age groups, feature binding was enhanced by low navigation and itinerary control conditions. The subjective sense of remembering was boosted by the itinerary control in older adults. Memory performance following high navigation was specifically linked to variability in executive functions. The present findings suggest that the decision of the itinerary is beneficial to boost episodic memory in aging, although it does not eliminate age-related deficits. Active navigation can also enhance episodic memory when it is not too demanding for subjects' cognitive resources.

This review suggests several hypotheses about the cognitive developmental mechanisms involved in the motor deficits of children with cerebral palsy. We suggest a new theory that visuospatial deficits involving the manipulation of multiple spatial reference frames are crucial components of the disorder in spatial orientation, manipulation, locomotion, navigation, and even social interactions. We review basic knowledge about the brain networks involved in spatial memory and cognition. We then present several potential paradigms for studying specific deficits. We consider first the use of vestibular signals for egocentric spatial orientation in children and the ‘locomotor trajectory paradigm’ for studying gaze anticipation and perceptual components of walking. We then describe new paradigms for studying egocentric and allocentric strategies in spatial tasks: the ‘virtual path length’, the ‘virtual palace’ and the ‘virtual star maze’. We also consider paradigms involving the use of other persons and perspective change from a first person's to a third person's viewpoint as reference in spatial tasks or social interactions: the ‘designation’ paradigm, the ‘harlequin’, and the ‘tightrope walker’. Finally, we briefly present a new experimental set up involving a ‘virtual carpet’, which follows previous studies of cognitive strategies for generating locomotor trajectories using the ‘magic carpet’ and which will allow a large variety of studies involving executive functions and inhibition of the first-appearing strategies during development. Several of these new paradigms could be used for remediation.

Experimental studies of visual mechanisms suggests that the CNS represents image information with respect to preferred horizontal and vertical axes, as shown by a phenomenon known as the "oblique effect". In the current study we used this effect to evaluate the influence of gravity on the representation and storage of visual orientation information. Subjects performed a psychophysical task in which a visually-presented stimulus line was aligned with the remembered orientation of a reference stimulus line presented moments before. The experiments were made on 5 cosmonauts during orbital space flight and additionally on 13 subjects in conditions of normal gravity with a tilting chair. Data were analyzed with respect to response variability and timing. On earth, these measurements for this task show a distinct preference for horizontally and vertically oriented stimuli when the body and gravitational axes were aligned. This preference was markedly decreased or disappeared when the body axis was tilted with respect to gravity; this effect was not connected with ocular counter-rolling nor could we find a preference of any other intermediate axis between the gravity and body aligned axes. On the other hand, the preference for vertical and horizontal axes was maintained for tests performed in microgravity over the course of a 6 month flight, starting from flight day 6. We concluded that subjects normally process visual orientation information in a multi-modal reference frame that combines both proprioceptive and gravitational cues when both are available, but that a proprioceptive reference frame is sufficient for this task in the absence of gravity after a short period of adaptation. Some of the results from this study have been previously published in a preliminary report. Grant numbers: 99-04-48450.

In this paper we address the problem of coverage area with multi-robot system by giving an autonomy level to single robot as well as the team. The coverage concept is based on Voronoi algorithm and it applied to extract the minimum number of views from the supervised environment. Human Robot Interface was developed to allow user to selects minimum points’ locations where robots have to achieve the supervision task. Moreover, user can access at any time through the interface watching video streams feedback coming from robots and semi-autonomous robots can locally correct their paths if probability collusion, with the environment, is predicted based on new adapted Active Counter Model. However, failed robots can easily request help from user, where, this last acts overcoming the robot from its unlikely situation. The coverage strategy that we proposed combines the real robot motion (by consideration motion error and process the correction method) and the human robot interaction as well as the supervision paradigms.

Gravity plays a role in many different levels of human motor behavior. It dictates the laws of motion of our body and limbs, as well as of the objects in the external world with which we wish to interact. The dynamic interaction of our body with the world is molded within gravity's constraints. The role played by gravity in the perception of visual stimuli and the elaboration of human movement is an active research theme in the field of Neurophysiology. Conditions of microgravity, coupled with techniques from the world of virtual reality, provide a unique opportunity to address these questions concerning the function of the human sensorimotor system [1]. The ability to measure movements of the head and to update in real time the visual scene presented to the subject based on these measurements is a key element in producing a realistic virtual environment. A variety of head-tracking hardware exists on the market today [2–4], but none seem particularly well suited to the constraints of working with a space station environment. Nor can any of the existing commercial systems meet the more stringent requirements for physiological experimentation (high accuracy, high resolution, low jitter, low lag) in a wireless configuration. To this end, we have developed and tested a hybrid opto-inertial 6 degree-of-freedom tracker based on existing inertial technology [5–8]. To confirm that the inertial components and algorithms will function properly, this system was tested in the microgravity conditions of parabolic flight. Here we present the design goals of this tracker, the system configuration and the results of 0g and 1g testing.

The eye perceives the length of vertical and horizontal lines with an inherent asymmetry. A vertical line having the same length as a horizontal one is usually perceived to be longer. In this experimental investigation we tested the hypothesis that gravity has a direct role in producing the observed perceptual asymmetry. To this end we performed experiments in weightlessness during long-orbital space flights onboard the MIR station. Subjects performed a psychophysical task in which the length of a visually-presented vertical line was adjusted to match the length of a horizontal reference. On Earth, almost all subjects produce errors in adjusting the length of the vertical line, consistently under-estimating the length of the horizontal reference. The asymmetry of perception of the line lengths persisted in weightlessness. From these results we conclude that the phenomena of asymmetry of perception of the lengths of vertical and horizontal lines is not dependent on gravity, but is instead defined by properties of the system of internal representation. Grant numbers: 99-04-48450.