Virtual reality to characterize anticipation skills of top-level 4 x 100 m relay athletes.

One marker of expertise in sport is athletes' ability to anticipate future events. In the 4 × 100 m relay, these anticipation skills are an essential asset for initiating their run at the right time. However, no study has focused on describing the underlying perceptual-motor processes involved.

An interdisciplinary framework to optimize the anticipation skills of high-level athletes using virtual reality.

The ambition of our contribution is to show how an interdisciplinary framework can pave the way for the deployment of innovative virtual reality training sessions to improve anticipation skills in top-level athletes. This improvement is so challenging that some authors say it is like "training for the impossible". This framework, currently being implemented as part of a project to prepare athletes for the 2024 Olympic Games in Paris, based on the ecological-dynamics approach to expertise, is innovative in its interdisciplinary nature, but also and above all because it overcomes the limitations of more traditional training methods in the field designed to optimize anticipation skills in top-level athletes.

Differences of gait adaptability behavior between young and healthy older adults during a locomotor pointing task in virtual reality.

Background: Gait adaptability training programs to prevent falls in healthy older adults can be proposed in virtual reality. The development of training programs requires the characterization of the target population.

Research Question: Before proposing an innovative training program to develop gait adaptability behavior of healthy older adults in fully immersive virtual reality, we had to compare gait adaptability behavior between healthy older adults and young adults in virtual reality.

Evaluation of assistance systems allowing older drivers to intercept moving inter-vehicular space.

Introduction: The objective of the present study was to test two Advanced Driving Assistance Systems (ADAS) designed to help older drivers to intercept a moving inter-vehicular space.

Method: Older and younger drivers were asked to intercept a moving inter-vehicular space within a train of vehicles in a driving simulator. Three ADAS conditions (No-ADAS, Head Down, Head Up) as well as five distinct speed regulation conditions were tested.

Honeybees Use Multiple Invariants to Control Their Altitude.

How do bees perceive altitude changes so as to produce safe displacements within their environment? It has been proved that humans use invariants, but this concept remains little-known within the entomology community. The use of a single invariant, the optical speed rate of change, has been extensively demonstrated in bees in a ground-following task. Recently, it has been demonstrated that another invariant, the splay angle rate of change, could also be used by bees to adjust their altitude.

An experimental setup for decoupling optical invariants in honeybees' altitude control.

Bees outperform pilots in navigational tasks, despite having 100,000 times fewer neurons. It is commonly accepted in the literature that optic flow is a key parameter used by flying insects to control their altitude. The ambition of the present work was to design an innovative experimental setup that would make it possible to determine whether bees could rely simultaneously on several optical invariants, as pilots do.

Validation of an immersive virtual reality device accepted by seniors that preserves the adaptive behavior produced in the real world.

Falls in the elderly are a major societal issue. Virtual reality appears as a relevant tool to propose gait training programs to prevent the occurrence of falls. The use of a head-mounted display allows overground walking during fully immersive virtual training sessions.

Floor and ceiling mirror configurations to study altitude control in honeybees.

To investigate altitude control in honeybees, an optical configuration was designed to manipulate or cancel the optic flow. It has been widely accepted that honeybees rely on the optic flow generated by the ground to control their altitude. Here, we create an optical configuration enabling a better understanding of the mechanism of altitude control in honeybees.

Studying the timescale of perceptual-motor (re)calibration following a change in visual display gain.

Experiencing a non-1:1 mapping between perception and action in everyday life is not common. It could be considered as a problem for our perceptual-motor system because of the need to adapt our goal-directed movement to different gains between movement and task spaces. In the Human Computer Interface domain, the main example of such a situation consists in switching from one operating system to another which requires to adapt our movement to different Control Display gains.

Ecological Entomology: How Is Gibson's Framework Useful?

To date, numerous studies have demonstrated the fundamental role played by optic flow in the control of goal-directed displacement tasks in insects. Optic flow was first introduced by Gibson as part of their ecological approach to perception and action. While this theoretical approach (as a whole) has been demonstrated to be particularly suitable for the study of goal-directed displacements in humans, its usefulness in carrying out entomological field studies remains to be established.

Acceptance of a Virtual Reality Headset Designed for Fall Prevention in Older Adults: Questionnaire Study.

Background: Falls are a common phenomenon among people aged 65 and older and affect older adults' health, quality of life, and autonomy. Technology-based intervention programs are designed to prevent the occurrence of falls and their effectiveness often surpasses that of more conventional programs. However, to be effective, these programs must first be accepted by seniors.

Eye position affects flight altitude in visual approach to landing independent of level of expertise of pilot.

The present study addresses the effect of the eye position in the cockpit on the flight altitude during the final approach to landing. Three groups of participants with different levels of expertise (novices, trainees, and certified pilots) were given a laptop with a flight simulator and they were asked to maintain a 3.71° glide slope while landing.

Judging arrival times of incoming traffic vehicles is not a prerequisite for safely crossing an intersection: Differential effects of vehicle size and type in passive judgment and active driving tasks.

Using a fixed-base driving simulator we compared the effects of the size and type of traffic vehicles (i.e., normal-sized or double-sized cars or motorcycles) approaching an intersection in two different tasks.

The Influence of the 'Trier Social Stress Test' on Free Throw Performance in Basketball: An Interdisciplinary Study.

The aim of the present study was to explore the relationship between stress and sport performance in a controlled setting. The experimental protocol used to induce stress in a basketball free throw was the Trier Social Stress Test (TSST) and its control condition (Placebo-TSST). Participants (n = 19), novice basketball players but trained sportspersons, were exposed to two counterbalanced conditions in a crossover design.

A scale-based approach to interdisciplinary research and expertise in sports.

After more than 20 years since the introduction of ecological and dynamical approaches in sports research, their promising opportunity for interdisciplinary research has not been fulfilled yet. The complexity of the research process and the theoretical and empirical difficulties associated with an integrated ecological-dynamical approach have been the major factors hindering the generalisation of interdisciplinary projects in sports sciences. To facilitate this generalisation, we integrate the major concepts from the ecological and dynamical approaches to study behaviour as a multi-scale process.

High- and Low-Order Overtaking-Ability Affordances: Drivers Rely on the Maximum Velocity and Acceleration of Their Cars to Perform Overtaking Maneuvers.

Objective: The aim of this study was to answer the question, Do drivers take into account the action boundaries of their car when overtaking?

Background: The Morice et al. affordance-based approach to visually guided overtaking suggests that the "overtake-ability" affordance can be formalized as the ratio of the "minimum satisfying velocity" (MSV) of the maneuver to the maximum velocity (V(max)) of the driven car. In this definition, however, the maximum acceleration (A(max)) of the vehicle is ignored.

Drivers' decision-making when attempting to cross an intersection results from choice between affordances.

In theory, a safe approach to an intersection implies that drivers can simultaneously manage two scenarios: they either choose to cross or to give way to an oncoming vehicle. In this article we formalize the critical time for safe crossing (CT cross ) and the critical time for safe stopping (CT stop ) to represent crossing and stopping possibilities, respectively. We describe these critical times in terms of affordances and empirically test their respective contribution to the driver's decision-making process.

Is perception of self-motion speed a necessary condition for intercepting a moving target while walking?

While it has been shown that the Global Optic Flow Rate (GOFR) is used in the control of self-motion speed, this study examined its relevance in the control of interceptive actions while walking. We asked participants to intercept approaching targets by adjusting their walking speed in a virtual environment, and predicted that the influence of the GOFR depended on their interception strategy. Indeed, unlike the Constant Bearing Angle (CBA), the Modified Required Velocity (MRV) strategy relies on the perception of self-displacement speed.

Intercepting a moving traffic gap while avoiding collision with lead and trail vehicles: gap-related and boundary-related influences on drivers' speed regulations during approach to an intersection.

Using a fixed-base driving simulator, 15 participants actively drove their vehicle across a rural road toward an intersection. Their task was to safely cross the intersection, passing through a gap in the train of incoming traffic. Spatiotemporal task constraints were manipulated by varying the initial conditions (offsets) with respect to the time of arrival of the traffic gap at the intersection.

Intersection crossing considered as intercepting a moving traffic gap: effects of task and environmental constraints.

Safely crossing an intersection requires that drivers actively control their approach to the intersection with respect to characteristics of the flow of incoming traffic. To further our understanding of the perceptual-motor processes involved in this demanding manoeuvre, we designed a driving simulator experiment in which 13 participants actively negotiated intersections by passing through a gap in the train of incoming traffic. Task constraints were manipulated by varying the size of the traffic gap and the initial conditions with respect to the time of arrival of the traffic gap at the intersection.

The education of attention as explanation of variability of practice effects: learning the final approach phase in a flight simulator.

The present study reports two experiments in which a total of 20 participants without prior flight experience practiced the final approach phase in a fixed-base simulator. All participants received self-controlled concurrent feedback during 180 practice trials. Experiment 1 shows that participants learn more quickly under variable practice conditions than under constant practice conditions.

How information guides movement: intercepting curved free kicks in soccer.

Previous studies have shown that balls subjected to spin induce large errors in perceptual judgments (Craig, Berton, Rao, Fernandez, & Bootsma, 2006; Craig et al., 2009) due to the additional accelerative force that causes the ball's flight path to deviate from a standard parabolic trajectory. A recent review however, has suggested that the findings from such experiments may be imprecise due to the decoupling of perception and action and the reliance on the ventral system (van der Kamp, Rivas, van Doorn, & Savelsbergh, 2008).

Visual control of walking velocity.

Even if optical correlates of self-motion velocity have already been identified, their contribution to the control of displacement velocity remains to be established. In this study, we used a virtual reality set-up coupled to a treadmill to test the role of both Global Optic Flow Rate (GOFR) and Edge Rate (ER) in the regulation of walking velocity. Participants were required to walk at a constant velocity, corresponding to their preferred walking velocity, while eye height and texture density were manipulated.

Top-level players' visual control of interceptive actions: Bootsma and van Wieringen (1990) 20 years later.

Using a two-step approach, Van Soest et al. (2010) recently questioned the pertinence of the conclusions drawn by Bootsma and Van Wieringen (1990) with respect to the visual regulation of an exemplary rapid interceptive action: the attacking forehand drive in table tennis. In the first step, they experimentally compared the movement behaviors of their participants under conditions with and without vision available during the execution of the drive.

The integration of temporally shifted visual feedback in a synchronization task: The role of perceptual stability in a visuo-proprioceptive conflict situation.

The present study examined whether the beneficial role of coherently grouped visual motion structures for performing complex (interlimb) coordination patterns can be generalized to synchronization behavior in a visuo-proprioceptive conflict situation. To achieve this goal, 17 participants had to synchronize a self-moved circle, representing the arm movement, with a visual target signal corresponding to five temporally shifted visual feedback conditions (0%, 25%, 50%, 75%, and 100% of the target cycle duration) in three synchronization modes (in-phase, anti-phase, and intermediate). The results showed that the perception of a newly generated perceptual Gestalt between the visual feedback of the arm and the target signal facilitated the synchronization performance in the preferred in-phase synchronization mode in contrast to the less stable anti-phase and intermediate mode.