Effect of narrowing the base of support on the gait, gaze and quiet eye of elite ballet dancers and controls

Acceptability and Feasibility of Portable Eye-Tracking Technology within a Children's Dynamic Sport Context: An Exploratory Study with Boys Who Play Grassroots Football

Teaching practices are moving from decontextualised to more representative curricula. Although this is argued to be a positive step, low motor competence is a continual issue in primary-aged school children. One methodological approach to investigate ways to improve motor competence, eye tracking, is moving to more representative tasks. So far, eye-tracking research using static activities has demonstrated a positive association between motor competence and earlier fixation and longer duration. However, this research has been constrained to laboratory settings and tasks, or discrete activities (e.g., throw and catch). This study seeks to understand how to conduct more representative eye-tracking research in primary school-aged children. To this end, thirteen 10-11-year-old children were fitted with an eye-tracker during a typical football coaching session. Children were asked acceptability-based questions, and eye-gaze data were captured to illustrate what children attended to under a representative dynamic football-based activity. Based on the voices of children and captured eye-gaze data, six practical implications for research in this population are proposed: (1) conduct eye-tracking research indoors (where possible); (2) ensure long hair or fringes are secured so as not to obscure line of sight; (3) run the same activity to increase comparability across children wearing the eye-tracker; (4) use a properly fitted backpack (if a backpack is to be used); (5) assure children about the capability and hardiness of the eye-tracker, as they do not need to change the way they move; (6) explain there may be some discomfort with the nose clip, head strap, and battery weight and ensure that children wish to continue.

Pupil diameter as a biomarker of effort in goal-directed gait

Subjects' eye movement behavior related to cognitive effort during gait was measured as subjects walked to perform low and high cognitive load tasks. We found that all pupil diameter measures, fixation durations, and the proportion of blink duration changed significantly during gait as a function of task load. In contrast, the number of fixations, saccade durations and travel time did not change significantly as a function of task load. Findings showed that pupil diameter was the best predictor of task load during one's gait preceding the performance of the task. While other studies have demonstrated the importance of eye fixation characteristics during gait, our findings showed that eye measures related to pupil diameter were better at detecting cognitive load while walking to perform a task compared to eye fixation data. We also found that cognitive effort was not limited to just the performance of the task, but that it was also exerted during one's gait preceding the performance of the task. Therefore, the additional attention demand caused by an increase in task complexity may result in less attentional resources being available to adequately handle distractions (such as obstacle avoidance) while walking to perform the task. Consequently, this may increase the likelihood of falls in those individuals with lower attentional capacity.

Hierarchical goal effects on center of mass velocity and eye fixations during gait

The purpose of this study was to determine the effect of hierarchical goal structure of a yet-to-be performed task on gait and eye fixation behavior while walking to the location of where the task was to be performed. Subjects performed different goal-directed tasks representing three hierarchical levels of planning. The first level of planning consisted of having the subject walk to a bookcase on which an object (a cup) was located in the middle of a shelf. The second level of planning consisted of walking to the bookcase and picking up the cup which was in the middle, on the right side, or on the left side of the bookcase shelf. The third level of planning consisted of walking to the bookcase, picking up the cup which was located in the middle of the bookcase shelf, and moving it to a higher shelf. Findings showed that hierarchal goals do affect center of mass velocity and eye fixation behavior. Center of mass velocity to the bookcase increased with an increase in the number of goals. Subjects decreased gait velocity as they approached the bookcase and adjusted their last steps to accommodate picking up the cup. The findings also demonstrated the important role of vision in controlling gait velocity in goal-directed tasks. Eye fixation duration was more important than the number of eye fixations in controlling gait velocity. Thus, the amount of information gained through object fixation duration is of greater importance than the number of fixations on the object for effective goal achievement.

The 'Quiet Eye' and Motor Performance: A Systematic Review Based on Newell's Constraints-Led Model

INTRODUCTION

The quiet eye (final fixation to a specific target prior to movement initiation) is a perceptual skill robustly associated with expertise and superior performance. The benefit of the phenomenon has been demonstrated in a range of sporting tasks. The mechanism(s) underpinning this phenomenon are much-debated and are associated with varying assumptions.

OBJECTIVE

This systematic review categorizes previous quiet eye research based on Newell's 1986 model of interacting constraints.

DATA SOURCES

Three electronic databases (Web of Science, Scopus, PubMed) were searched from inception until February 2015. Details of relevant studies were also obtained from one literature review and two book chapters.

ELIGIBILITY CRITERIA AND SYNTHESIS METHODS

To frame the discussion of research evidence concerning the quiet eye, previous studies were evaluated based on a classification of manipulating performer, environment, and task constraints. Additionally, associative studies (without specific constraints), and interacting constraints (affecting more than one constraint) were considered.

RESULTS

This review emphasizes that the quiet eye is beneficial for performing aiming tasks and that Newell's constraints model provides a useful framework for organizing knowledge in this area.

CONCLUSION

Despite the robust research on the value of the quiet eye, several gaps in current knowledge exist regarding the mechanism of the quiet eye effect.

Visuomotor control of human adaptive locomotion: understanding the anticipatory nature

To maintain balance during locomotion, the central nervous system (CNS) accommodates changes in the constraints of spatial environment (e.g., existence of an obstacle or changes in the surface properties). Locomotion while modifying the basic movement patterns in response to such constraints is referred to as adaptive locomotion. The most powerful means of ensuring balance during adaptive locomotion is to visually perceive the environmental properties at a distance and modify the movement patterns in an anticipatory manner to avoid perturbation altogether. For this reason, visuomotor control of adaptive locomotion is characterized, at least in part, by its anticipatory nature. The purpose of the present article is to review the relevant studies which revealed the anticipatory nature of the visuomotor control of adaptive locomotion. The anticipatory locomotor adjustments for stationary and changeable environment, as well as the spatio-temporal patterns of gaze behavior to support the anticipatory locomotor adjustments are described. Such description will clearly show that anticipatory locomotor adjustments are initiated when an object of interest (e.g., a goal or obstacle) still exists in far space. This review also show that, as a prerequisite of anticipatory locomotor adjustments, environmental properties are accurately perceived from a distance in relation to individual’s action capabilities.

Zielinstruktionen, räumliche Quiet-Eye-Verankerung und Bewegungsparametrisierung

Die motorikwissenschaftliche Befundlage zum sogenannten „Quiet Eye“ weist darauf hin, dass hohe sportmotorische Leistungen, insbesondere in Präzisionsaufgaben, mit einer langen finalen Fixation vor der Bewegungsentfaltung einhergehen. Ein Mechanismus, der diesen Zusammenhang aus einer kognitionspsychologischen Perspektive erklären könnte, ist die Optimierung von Informationsverarbeitungsprozessen der Bewegungsparametrisierung. Diese Annahme wurde durch eine experimentelle Manipulation von Zielinstruktionen in einer Ballwurfaufgabe untersucht. Zum einen zeigen die Ergebnisse, dass sich die räumliche Verankerung des Quiet Eye in Abhängigkeit der variierten Aufgabenziele verändert; zum anderen deuten die Befunde darauf hin, dass sich Veränderungen der Verankerung im Bewegungsresultat niederschlagen. Damit wird ein kognitiver Wirkmechanismus plausibilisiert, nach dem die Bewegungsgenauigkeit durch Zielinstruktion via räumliche Quiet-Eye-Verankerung bestimmt wird.

Mind over muscle: the role of gaze control, spatial cognition, and the quiet eye in motor expertise

In the course of all motor behavior, the brain is limited in how much information it can process and act upon at a time. Performers must constantly decide where to look, what to attend to, and how to time fixated information with precisely controlled actions. The gaze can be directed to only one location at a time and information central to success must be selected from spatially complex environments, most often under severe time constraints. The coordination of these processes is explored in this Special issue in a number of motor tasks, including golf, soccer, law enforcement, and ballet. The papers describe the visual information and quiet eye characteristics that underlie the ability to make decisions under complex task conditions and the relationship between control of the gaze and task outcomes. With the attainment of motor expertise, measureable changes occur within the gaze, cognitive, and neural systems that are useful in training, rehabilitation, and the treatment of motor deficits.