A larger augmented-reality field of view improves interaction with nearby holographic objects.

Augmented-reality (AR) applications have shown potential for assisting and modulating gait in health-related fields, like AR cueing of foot-placement locations in people with Parkinson's disease. However, the size of the AR field of view (AR-FOV), which is smaller than one's own FOV, might affect interaction with nearby floor-based holographic objects. The study's primary objective was to evaluate the effect of AR-FOV size on the required head orientations for viewing and interacting with real-world and holographic floor-based objects during standstill and walking conditions.

Gait-modifying effects of augmented-reality cueing in people with Parkinson's disease.

Introduction: External cueing can improve gait in people with Parkinson's disease (PD), but there is a need for wearable, personalized and flexible cueing techniques that can exploit the power of action-relevant visual cues. Augmented Reality (AR) involving headsets or glasses represents a promising technology in those regards. This study examines the gait-modifying effects of real-world and AR cueing in people with PD.

Perceived cognitive fatigue has only marginal effects on static balance control in healthy young adults.

We examined the influence of perceived cognitive fatigue on static balance control in healthy young adults to gain greater clarity about this issue than provided in previous research. Based on the prevailing assumption in pertinent literature, we hypothesized that the influence of cognitive fatigue on balance control depends on the attentional effort required by the balance tasks being performed. To test this hypothesis, 44 young adults (24 women and 20 men) were alternately assigned to either the experimental group that was cognitively fatigued (using the 16-min TloadDback-task with individualized settings) or the control group (who watched a documentary).

On the physiology of interruption after unexpectedness.

We tested whether surprise elicits similar physiological changes as those associated with orienting and freezing after threat, as surprise also involves a state of interruption and attention for effective action. Moreover, because surprise is primarily driven by the unexpectedness of an event, initial physiological responses were predicted to be similar for positive, neutral, and negative surprises. Results of repetition-change studies (4 + 1 in Supplemental Materials) showed that surprise lowers heart rate (Experiments 1-4) and increases blood pressure (Experiment 4).

Unveiling Intermittency in the Control of Quiet Upright Standing: Beyond Automatic Behavior.

The control of posture, as in quiet upright standing, is distributed among postural reflexes and higher (cortical) centers. According to the theory of "intermittent control," the control of posture involves a rapid succession of brief periods of postural stability, during which the body dwells relatively motionless in a particular posture, and postural instability, during which the body rapidly transits to a new stable point. This theory assumes a combination of stiffness control, keeping the body in the same position, and top-down ballistic control, moving the body to a new reference position.

Balance Performance in Autism: A Brief Overview.

Children with autism not only have limited social and communicative skills but also have motor abnormalities, such as poor timing and coordination of balance. Moreover, impaired gross motor skills hamper participation with peers. Balance control is interesting from a cognitive science perspective, since it involves a complex interplay between information processing, motor planning, and timing and sequencing of muscle movements.

Evidence for Sequential Performance Effects in Professional Darts.

The study of sequential effects in aiming tasks might shed light on the organization of repetitive motor performances over time. To date, investigations of such effects in sports have been limited and yielded mixed results. Given the relatively short time intervals between successive attempts, and the absence of defensive interventions, dart throwing provides a potentially fruitful testing ground for examining the presence of sequential performance effects in the motor domain.

The effect of fear of falling on vestibular feedback control of balance.

Vestibular sensation contributes to cervical-head stabilization and fall prevention. To what extent fear of falling influences the associated vestibular feedback processes is currently undetermined. We used galanic vestibular stimulation (GVS) to induce vestibular reflexes while participants stood at ground level and on a narrow walkway at 3.

Back off! The effect of emotion on backward step initiation.

The distance regulation (DR) hypothesis states that actors are inclined to increase their distance from an unpleasant stimulus. The current study investigated the relation between emotion and its effect on the control of backward step initiation, which constitutes an avoidance-like behavior. Participants stepped backward on a force plate in response to neutral, high-arousing pleasant and high-arousing unpleasant visual emotional stimuli.

Words That Move Us. The Effects of Sentences on Body Sway.

According to the embodied cognition perspective, cognitive systems and perceptuo-motor systems are deeply intertwined and exert a causal effect on each other. A prediction following from this idea is that cognitive activity can result in subtle changes in observable movement. In one experiment, we tested whether reading various sentences resulted in changes in postural sway.

Effects of attentional focus on walking stability in elderly.

Introduction: Balance performance in the elderly is related to psychological factors such as attentional focus. We investigated the effects of internal vs. external focus of attention and fall history on walking stability in healthy older adults.

Effect of Constrained Arm Posture on the Processing of Action Verbs.

Evidence is increasing that brain areas that are responsible for action planning and execution are activated during the information processing of action-related verbs (e.g., or ).

Influence of focus of attention, reinvestment and fall history on elderly gait stability.

Falls represent a substantial risk in the elderly. Previous studies have found that a focus on the outcome or effect of the movement (external focus of attention) leads to improved balance performance, whereas a focus on the movement execution itself (internal focus of attention) impairs balance performance in elderly. A shift toward more conscious, explicit forms of motor control occurs when existing declarative knowledge is recruited in motor control, a phenomenon called reinvestment.

Framing visual roll-motion affects postural sway and the subjective visual vertical.

Effects of visual roll-motion on postural sway and the subjective visual vertical (SVV) often is studied using mechanical devices, whereas electronic displays offer cheaper and more flexible alternatives. These devices typically emit and reflect light scattered by the edges of the screen, providing Earth-fixed cues of verticality. These cues may decrease the effects of rotating stimuli, a possibility that has not been studied explicitly before in one experimental design.

The Effect of Optokinetic Stimulation on Perceptual and Postural Symptoms in Visual Vestibular Mismatch Patients.

Background: Vestibular patients occasionally report aggravation or triggering of their symptoms by visual stimuli, which is called visual vestibular mismatch (VVM). These patients therefore experience discomfort, disorientation, dizziness and postural unsteadiness.

Objective: Firstly, we aimed to get a better insight in the underlying mechanism of VVM by examining perceptual and postural symptoms.

Corrigendum: Arousal and exposure duration affect forward step initiation.

[This corrects the article on p. 1667 in vol. 6, PMID: 26579048.

Interaction between Depth Order and Density Affects Vection and Postural Sway.

Objective: Vection, a feeling of self-motion while being physically stationary, and postural sway can be modulated by various visual factors. Moreover, vection and postural sway are often found to be closely related when modulated by such visual factors, suggesting a common neural mechanism. One well-known visual factor is the depth order of the stimulus.

Arousal and exposure duration affect forward step initiation.

Emotion influences parameters of goal-directed whole-body movements in several ways. For instance, previous research has shown that approaching (moving toward) pleasant stimuli is easier compared to approaching unpleasant stimuli. However, some studies found that when emotional pictures are viewed for a longer time, approaching unpleasant stimuli may in fact be facilitated.

The Influence of Motor Imagery on Postural Sway: Differential Effects of Type of Body Movement and Person Perspective.

The present study examined the differential effects of kinesthetic imagery (first person perspective) and visual imagery (third person perspective) on postural sway during quiet standing. Based on an embodied cognition perspective, the authors predicted that kinesthetic imagery would lead to activations in movement-relevant motor systems to a greater degree than visual imagery. This prediction was tested among 30 participants who imagined various motor activities from different visual perspectives while standing on a strain gauge plate.

Attentional and sensory contributions to postural sway in children with autism spectrum disorder.

Postural control is known to depend on sensory and cognitive factors. Little is known about how children with autism spectrum disorder (ASD) regulate static balance, and to what extent vision and cognition contribute to the regulation of balance in this group. We compared a group of children with mild ASD and a group of age- and gender-matched controls on various postural tasks, standing on a Wii Balance Board.

Attention and postural control in patients with conversion paresis.

Objective: Current theories of conversion disorder (CD) propose that motor symptoms are related to heightened self-monitoring and excessive cognitive control of movements. We tested this hypothesis using quantification of performance on a continuous perceptuo-motor task involving quiet standing.

Methods: Twelve CD patients and matched controls maintained static balance on a force platform under various attention conditions: (1) with eyes open; (2) with eyes closed (requiring enhanced attention to proprioceptive information to regulate posture); and (3) while performing an attention demanding cognitive task.

Biomechanical organization of gait initiation depends on the timing of affective processing.

Gait initiation (GI) from a quiet bipedal posture has been shown to be influenced by the emotional state of the actor. The literature suggests that the biomechanical organization of forward GI is facilitated when pleasant pictures are shown, as compared to unpleasant pictures. However, there are inconsistencies in the literature, which could be due to the neural dynamics of affective processing.