Benefits of postural sway to succeed in goal-directed visual tasks.

When individuals stand, they sway and so have to maintain their balance. It is generally expected that task performance is worse when standing and swaying than when sitting and therefore not swaying. In contrast, we hypothesized that greater sway is associated with better task performance in the absence of external perturbations of posture.

Diabetic older women without peripheral neuropathy amplify body sway but are capable of improving postural stability during a saccadic gaze task.

Background: Diabetic older people tend to present deteriorated performance in balance and locomotion activities, even those without peripheral neuropathy. There is evidence that saccadic eye movements are used to reduce body sway in young and older healthy adults, but it has not been shown that diabetic older people preserve this visuomotor adaptation capacity.

Research Question: Are diabetic older women without peripheral neuropathy capable of improving postural stability during a saccadic gaze task?

Methods: Seventeen type 2 diabetic older women (68.

Modelling the relationships between EEG signals, movement kinematics and outcome in soccer kicking.

Unlabelled: The contribution of cortical activity (e.g. EEG recordings) in various brain regions to motor control during goal-directed manipulative tasks using lower limbs remains unexplored.

Parkinson's disease affects gaze behaviour and performance of drivers.

The aim of this study was to investigate the effects of PD and ageing on gaze behaviour and performance of drivers in a simulated task. Ten drivers with PD, ten neurologically healthy older drivers, and ten neurologically healthy younger adult drivers were asked to drive in a car simulator for three minutes, maintaining car speed between 100 and 120 km/h and avoiding collisions. Driver's eye movements were recorded.

Saccadic eye movement performance reduces visual manipulation influence and center of pressure displacements in older fallers.

This study examined changes in postural control and gaze performance of faller and non-faller older adults under conditions of visual tasks and optical flow manipulations. Fifteen older non-fallers (69.8 years, ± 3.

Motor strategy during postural control is not muscle fatigue joint-dependent, but muscle fatigue increases postural asymmetry.

The aim of this study was to investigate the effects of ankle and hip muscle fatigue on motor adjustments (experiment 1) and symmetry (experiment 2) of postural control during a quiet standing task. Twenty-three young adults performed a bipedal postural task on separate force platforms, before and after a bilateral ankle and hip muscle fatigue protocol (randomized). Ankle and hip muscles were fatigued separately using a standing calf raise protocol (ankle fatigue) on a step and flexion and extension of the hip (hip fatigue) sitting on a chair, at a controlled movement frequency (0.

Virtual reality head-mounted goggles increase the body sway of young adults during standing posture.

The aim of this study was to investigate the effects of wearing virtual reality head-mounted goggles (VR) on body sway in young adults. We run two experiments, in which we compared the body sway while standing during the conditions of 1) wearing and non-wearing VR with eyes-opened (experiment #1), 2) wearing and no-wearing VR with eyes-closed (experiment #2), and 3) wearing VR with eyes-opened when the scene was turned on and off (experiment #2). Forty-four (experiment #1) and fifteen (experiment #2) young adults were instructed to remain as still as possible on a force plate for 60-s and performed three trials in each quiet standing condition.

Wearing a head-mounted eye tracker may reduce body sway.

This study investigated the effects of wearing a head-mounted eye tracker on upright balance during different visual tasks. Twenty five young adults stood upright on a force plate while performing the visual tasks of fixation, horizontal saccades, and eyes closed, during eighteen trials wearing or not a head-mounted eye tracker. While wearing the eye tracker, participants showed a reduction in mean sway amplitude and velocity of the CoP in the AP and ML directions and more regular CoP fluctuations, in the ML axis in all conditions.

Parkinson's patients delay fixations when circumventing an obstacle and performing a dual cognitive task.

Background: People with Parkinson's disease (PD) do not differ from neurologically healthy individuals in obstacle circumvention during walking, therefore they are able to use visual feedback adequately to control motor behavior in this task. However, individuals are often distracted by the secondary task when circumventing an obstacle. An increased cognitive load can require prolonged gaze fixation time on a location of interest to compensate for longer information processing duration.

Combining experiences of race gaming and natural driving affects gaze location strategy in simulated context.

The aims of the study were to investigate the effects of race gaming experience in playing racing video games on gaze behaviour and performance of drivers and the effects of natural driving experience on gaze behaviour and performance of gamers. Thirty participants, divided into drivers-gamers, drivers-non-gamers and non-drivers-gamers, were asked to drive in a race circuit as fast as possible while their eye movements were recorded. Drivers-gamers spent more time looking at the lane than non-drivers-gamers.

Effects of Ankle Muscle Fatigue and Visual Behavior on Postural Sway in Young Adults.

Ankle muscle fatigue has been shown to increase body sway. In addition, body sway in quiet upright standing is reduced when saccadic eye movements are performed. The purpose of this study was to investigate the effects of visual information manipulation on postural control during ankle muscle fatigue in young adults.

Semi tandem base of support degrades both saccadic gaze control and postural stability particularly in older adults.

Differences in the postural stabilization of older and young adults have been shown to be task-dependent on both visual and postural challenges; however, the gaze behavior during such tasks has rarely been examined. This study investigated the effects of horizontal and vertical saccades on gaze control, center of pressure (CoP) and head displacement of young and older adults on different bases of support. Ten young adults (20.

Adverse effects of anxiety on attentional control differ as a function of experience: A simulated driving study.

This study tested whether adverse effects of state anxiety on attention and performance may be modulated by experience. Sixteen experienced and eleven inexperienced drivers drove in a simulator under low- and high-stress conditions. Anxiety was manipulated by competition, the presence of an evaluator, external video camera, and traffic noise.

Influence of obstacle color on locomotor and gaze behaviors during obstacle avoidance in people with Parkinson's disease.

The color of an obstacle may enable a more detailed view of the environment to facilitate obstacle avoidance. However, people with Parkinson's disease (PD) present visual contrast and color detection dysfunction, which could affect obstacle avoidance according to obstacle color. Thus, the aim of this study was to investigate the influence of obstacle color on locomotor and gaze behavior during obstacle avoidance in people with PD and neurologically healthy older individuals.

Obstacle circumvention and eye coordination during walking to least and most affected side in people with Parkinson's disease.

Background: The mechanisms that contribute to gait asymmetry in people with Parkinson's disease (PD) are unclear, mainly during gait with greater environmental demand, such as when an obstacle is circumvented while walking.

Objective: The aim of this study was to investigate the effects of obstacle circumvention of the least and most affected side on motor and gaze behavior in people with PD under/without the effects of dopaminergic medication.

Methods: Fifteen people with PD and 15 matched-control individuals were instructed to walk along a pathway, at a self-selected velocity, and to circumvent an obstacle, avoiding contact with it.

Gaze position interferes in body sway in young adults.

Postural control is influenced by eye movements. Gaze fixation, which comprises a component of ocular vergence, is important in the acquisition of highly specific task information, but its relation to postural control is little investigated. The aim of the study was to investigate the effects of gaze fixation position (central and lateral fixations) on postural sway in young adults.

Postural Control During Cascade Ball Juggling: Effects of Expertise and Base of Support.

Cascade ball juggling is a complex perceptual motor skill which requires efficient postural stabilization. The aim of this study was to investigate effects of experience (expert and intermediate groups) and foot distance (wide and narrow stances) on body sway of jugglers during three ball cascade juggling. A total of 10 expert jugglers and 11 intermediate jugglers participated in this study.

Effects of disease severity and medication state on postural control asymmetry during challenging postural tasks in individuals with Parkinson's disease.

The aim of this study was to investigate the effects of disease severity and medication state on postural control asymmetry during challenging tasks in individuals with Parkinson's disease (PD). Nineteen people with PD and 11 neurologically healthy individuals performed three standing task conditions: bipedal standing, tandem and unipedal adapted standing; the individuals with PD performed the tasks in ON and OFF medication state. The participants with PD were distributed into 2 groups according to disease severity: unilateral group (n=8) and bilateral group (n=11).

Saccadic and smooth pursuit eye movements attenuate postural sway similarly.

Saccadic eye movements reduce body sway, yet visually pursuing a moving dot seems to increase body sway. However, how these two types of eye movements affect postural control remains ambiguous, particularly for smooth pursuit eye movements. The aim of this study was to examine the effects of saccade and smooth pursuit eye movements on body sway magnitude during low and high frequencies.

Explicit and implicit knowledge of environment states induce adaptation in postural control.

The aim of this study was to investigate the effects of explicit and implicit knowledge about visual surrounding manipulation on postural responses. Twenty participants divided into two groups, implicit and explicit, remained in upright stance inside a "moving room". In the fourth trial participants in the explicit group were informed about the movement of the room while participants in the implicit group performed the trial with the room moving at a larger amplitude and higher velocity.

Adaptive visual re-weighting in children's postural control.

This study investigated how children's postural control adapts to changes in the visual environment and whether they use previous experience to adjust postural responses to following expositions. Four-, eight-, and twelve-year-old children (10 in each group) and 10 young adults stood upright inside of a moving room during eight trials each lasting one-minute. In the first trial, the room was stationary.

Dynamics of inter-modality re-weighting during human postural control.

Flexible and stable postural control requires adaptation to changing environmental conditions, a process which requires re-weighting of multisensory stimuli. Recent studies, as well as predictions from a computational model, have indicated a reciprocal re-weighting relationship between modalities when a sensory stimulus changes amplitude. As one modality is down-weighted, another is up-weighted to compensate (and vice versa).

Age-related changes in postural control sensory reweighting.

The aim of this study was to investigate the adaptive process in the coupling between visual information and body sway in children postural control. Twenty-seven children from 4-, 8- and 12-year-olds and ten adults stood upright inside of a moving room. In the first 2 min, the room was moved continuously at frequency of 0.