Attention, Perception, and Action in a Simulated Decision-Making Task.

Over the last decade, research on the visual focus of attention has become increasingly popular in psychological science. The focus of attention has been shown to be important in fast team-sport games. The authors developed a method that measures the extent of the attentional focus and perceptual capabilities during performance of a sport-specific task. The participants were required to judge different player configurations on their left and right sides with varying visual angles between the stimuli. In keeping with the notion that the focus of attention is smaller than the visual field, attentional performance was poorest at the wider viewing angles compared with perceptual performance. Moreover, the team-sport players were better able to enlarge their attentional focus and make correct decisions more frequently than individual athletes, particularly when a motor response was required. The findings provide a new perspective, dissociating the attentional and perceptual processes that affect decision making under various response modes.

Disguise and Deception of Action Outcomes Through Sports Garment Design Impair Anticipation Judgments.

The ability to disguise and deceive action outcomes was examined by manipulating sports garments. In Experiment 1, those with higher and lower skill levels in anticipation predicted the throw direction of an opponent who wore a garment designed to disguise kinetic-chain information. Higher skill anticipators were more adversely affected by the disguise garment than the lower skill anticipators, demonstrating that disguise removed the anticipation advantage. In Experiment 2, using the same occlusion methodology, the effect of deception was examined using 2 garments designed to create visual illusions of motion across the proximal-to-distal sequence of the thrower's action and compared with a white-garment control. Performances for the deceptive garments were reduced relative to the control garment at the earliest occlusion points for the rightmost targets, but this effect was reversed for the leftmost targets at the earliest occlusion point, suggesting that the visual illusion garments were deceiving participants about motion information from the proximal-to-distal sequence of the action.

Is Anticipation Skill Learning Bayesian?

Purpose: The aims of this study were to examine the learning of anticipation skill in the presence of kinematic and outcome probabilities information, and to see if this learning exhibited characteristics of Bayesian integration. Method: Participants with no competitive tennis playing experience watched tennis player stimuli playing forehand tennis shots and were tasked with predicted shot outcomes. Accuracy, response times and perceived task effort were recorded, pre, post and during four acquisition blocks where outcome feedback was provided. In both Experiment 1 and 2, kinematic information about shot direction was either present in the training group stimuli or absent. In Experiment 1, left/right shot probability information remained equi-probable for both groups. In Experiment 2, both groups also trained with a bias in the shot outcome probability toward one shot direction on 80% of the trials across acquisition blocks (and were not told about this manipulation). Results: Pre-to-post anticipation performance improved in the presence of kinematic (EXP 1) or both information sources (EXP 2). Pre-to-post improvements in the presence of shot outcome probability information were congruent with the bias in the shot direction trained (EXP 2). Superior anticipation performance was found when both information sources were present. The presence of kinematic information resulted in increased perceived effort during early training (EXP 1 & 2). Bayesian odds ratios indicated that shot direction probabilities and kinematic information were integrated during anticipation skill learning. Conclusion: Learning with shot direction probabilities and kinematic information shows characteristics of Bayesian integration.

No Difference in the Acute Effects of Randomization vs. Blocking of Units of Lower-Extremity Proprioceptive Training on Balance and Postural Control in Young Healthy Male Adults.

Random practice is a form of differential learning and its favorable acute effects on motor performance are well described when visual tasks are practiced. However, no study to date has investigated the acute effects of differential learning using variable proprioceptive stimuli instead of the visual cues. The aim of the present study was to compare the acute effects of randomized versus blocked lower-extremity proprioceptive training stimuli on balance and postural adjustments. In two conditions, healthy young males (n = 15, age = 23 years) performed 16 one-legged landings on a board tilted in four directions: 1) tilt direction unknown and randomized and 2) tilt direction known with order of presentation blocked. Multi-segmental angular sway while balancing on an unstable surface and postural responses to perturbation stimulus by surface tilts were measured before and 4 min after training. Overall frontal-plane postural sway on the unstable surface decreased (p < 0.05, η2 = 0.022) in both conditions, while sagittal-plane postural sway remained unchanged. When the surface was toes-up tilted in the perturbation test, the sagittal-plane shank-thigh-pelvis alignment improved in both conditions (p < 0.05, η2 = 0.017), but the direction of the segmental positioning was non-uniform across participants. We conclude that randomization vs. blocking of units of lower-extremity proprioceptive training did not affect balance and postural control in our cohort of healthy young adults but the improvements were test-specific.

Frontal Plane Neurokinematic Mechanisms Stabilizing the Knee and the Pelvis during Unilateral Countermovement Jump in Young Trained Males.

(1) The unilateral countermovement jump is commonly used to examine frontal plane kinetics during unilateral loading and to identify athletes with an increased risk of lower limb injuries. In the present study, we examined the biomechanical mechanisms of knee and pelvis stabilization during unilateral vertical jumps. (2) Healthy males performed jumps on a force plate with the dominant leg. Activity of the dominant-side gluteus medius and the contralateral-side quadratus lumborum and erector spinae muscles was recorded with surface EMG. The EMG data were normalized to the EMG activity recorded during maximal voluntary isometric hip abduction and lateral trunk flexion contractions. During jumps, the propulsive impulse was measured, and the pelvis and thigh segmental orientation angles in the frontal plane were recorded and synchronized with the EMG data. (3) The magnitude of knee valgus during the jump did not correlate with hip abduction force, but negatively correlated with gluteus medius activity. This correlation became stronger when gluteus medius activity was normalized to hip abduction force. Propulsive impulse did not correlate with any neuromechanical measurement. (4) We conclude that hip abduction force itself does not regulate the magnitude of knee valgus during unilateral jumps; rather, the gluteus medius should be highly activated to increase frontal-plane knee joint stability.

Gaze behavior in social interactions between beach volleyball players-An exploratory approach.

Previous research has indicated that social interactions and gaze behavior analyses in a group setting could be essential tools in accomplishing group objectives. However, only a few studies have examined the impact of social interactions on group dynamics in team sports and their influence on team performance. This study aimed to investigate the effects of game performance pressure on the gaze behavior within social interactions between beach volleyball players during game-like situations. Therefore, 18 expert beach volleyball players conducted a high and a low game performance pressure condition while wearing an eye tracking system. The results indicate that higher game performance pressure leads to more and longer fixation on teammates' faces. A higher need for communication without misunderstandings could explain this adaptation. The longer and more frequent look at the face could improve the receiving of verbal and non-verbal information of the teammate's face. Further, players showed inter-individual strategies to cope with high game performance pressure regarding their gaze behavior, for example, increasing the number of fixations and the fixation duration on the teammate's face. Thereby, this study opens a new avenue for research on social interaction and how it is influenced in/through sport.

Pedobarographic Statistical Parametric Mapping of plantar pressure data in new and confident walking infants: A preliminary analysis.

In infancy, plantar pressure data during walking has been investigated through regional approaches, whilst the use pedobarographic Statistical Parametric Mapping (pSPM) has not been reported. Analysis of pressure data using pSPM is higher in resolution and can enhance understanding of foot function development, providing novel insights into plantar pressure changes. This work aims to detail the implementation of the pSPM data processing framework on infants' pressure data, comparing plantar pressure patterns between new and confident walking steps. Twelve infants walked across an EMED- xl platform. Steps were extracted and imported into MATLAB for analysis. Maximum pressure pictures were transformed to point clouds and registered within and between participants with iterative closest point and coherent point drift algorithms, respectively. Root mean square error (RMSE) was calculated within both registrations as a quality measure. Pressure patterns were compared between new and confident walking using nonparametric-paired sample SPM1D t-test. RMSEs were under 1 mm for both registration algorithms. In the transition to confident walking, significantly increasing pressure was detected in the left central forefoot. Implementing pSPM to infants' pressure data was non-trivial, as several phases of data processing were required to ensure a robust approach. Our analysis highlighted the presence of significant changes in pressure in central left forefoot after 2.2 months of walking, which have not been reported before. This can be explained as previous regional approaches in infancy considered the forefoot as whole, preventing detection of changes in discrete anatomical regions.

Coordination between motor and cognitive tasks in dual task gait.

BACKGROUND: Dual Task (DT) paradigms are frequently used by researchers and clinicians to examine the integrity of motor processes in many movement disorders. However, the mechanism of this interaction is not fully understood. Therefore, the aim of this study was to examine the within-stride interactions between cognitive and motor processes during dual task gait (DT). RESEARCH QUESTION: Do healthy young adults coordinate gait with secondary task processing? If so, is cognitive task processing capability associated with the coordination observed? METHODS: Nineteen healthy young adults walked for two minutes on a motorized treadmill whilst counting backwards in sevens from three-digit numbers. The coordination of calculation verbalizations with gait parameters were assessed across six phases of the gait cycle. Mid verbalization time points (VERMid) were used as points of high cognitive processing of the dual task and compared with the end of the verbalizations (VEREnd) as points of low cognitive processing. RESULTS: VERMid and VEREnd did not systematically occur in any phase of the gait cycle. However, 10/19 and 9/19 participants showed non-random distributions of verbalizations for VERMid and VEREnd time points respectively (p < 0.01), indicating that these walkers coordinated gait with the cognitive task. Analysis of subgroups of Verbalization Coordinators and Non-Coordinators showed slower verbalization response durations (VRD) for VERMid Coordinators compared to VERMid Non-Coordinators, indicating that VERMid Coordinators found the cognitive tasks more demanding. No differences were found in VRD for VEREnd Coordinators and VEREnd Non-Coordinators. SIGNIFICANCE: It was found that cognitive processing is coordinated with gait phases in some but not all healthy young adults during DT gait. When demands on cognitive processes are high, healthy young adults coordinate cognitive processing with phases of gait. Analysis of within-stride coordination may be of use for studying clinical conditions where gait and attentional cognition performance breaks down.

Three-dimensional foot shape analysis in children: a pilot analysis using three-dimensional shape descriptors.

BACKGROUND: Existing clinical measures to describe foot morphology are limited in that they are commonly two-dimensional, low in resolution and accuracy, and do not accurately represent the multi-planar and complex changes during development across childhood. Using three-dimensional (3D) scanner technology provides the opportunity to understand more about morphological changes throughout childhood with higher resolution and potentially more relevant 3D shape measures. This is important to advance the prevailing arguments about the typical development of children's feet and inform the development of appropriate clinical measures. 3D shape descriptors derived from 3D scanning can be used to quantify changes in shape at each point of the 3D surface. The aim of this study was to determine whether 3D shape descriptors derived from 3D scanning data can identify differences in foot morphology between children of different ages. METHODS: Fifteen children were recruited from three age groups (2, 5, and 7 years of age). Both feet were scanned in bipedal stance, using the Artec Eva (Artec Group, Luxembourg, Luxembourg) hand-held scanner. Three dimensional shape descriptors were extracted from the 3D scans of the right foot, to create histograms for each age group and heat maps of representative participants for comparison. RESULTS: There were changes to the dorsal, medial and lateral surfaces of the feet with age. The surfaces became less round along with an increase in indented areas. This is supported by the heat maps which demonstrated that the surfaces of the anatomical landmarks (e.g. the malleoli and navicular tuberosity) became more rounded and protruding, with indented surfaces appearing around these landmarks. On the plantar surface, the concavity of the midfoot was evident and this concavity extended into the midfoot from the medial aspect as age increased. CONCLUSIONS: The findings of this study indicated that with increasing age the foot becomes thinner in 3D, with bony architecture emerging, and the medial longitudinal arch (MLA) increases in area and concavity. Three-dimensional shape descriptors have shown good potential for locating and quantifying changes in foot structure across childhood. Three-dimensional shape descriptor data will be beneficial for understanding more about foot development and quantifying changes over time.