A Perception-Action Assessment of the Functionality of Peripheral Vision in Expert and Novice Australian Footballers.

While widely acknowledged as being important for team-sport performance, the contribution of peripheral vision is poorly understood. This study aimed to better understand the role of far peripheral vision in team sport by exploring how domain experts and novices used far peripheral vision to support decision making and action control. Expert (n = 25) and novice (n = 23) Australian football players completed a perception-only task to assess the extent of their peripheral field. Next, they completed two sport-specific variations (response and recognition) of a "no-look" pass task that required passing a ball to a teammate who appeared in their far peripheral field. In the perception-only task, novices outperformed experts. However, in the sport-specific action response and recognition tasks, experts demonstrated superior performance as they responded to the stimulus farther from central vision and more accurately. Results demonstrate expertise effects for the use of far peripheral vision in sport.

Experiential Knowledge Affects the Visual Search Behaviors of Sprint Coaches and Sport Biomechanists.

It is common for applied sport biomechanists and high-performance coaches to work closely together. A feature of this relationship is that both bring unique experiences and knowledge to the common goal of improving an athlete's performance. For sprint running, coaches and biomechanists place importance on different aspects of technique. The purpose of this paper was to determine if these differences in experiential knowledge impact coaches and biomechanists visual perception of sprinting technique. Sport biomechanists (n = 12) and, expert (n = 11) and developing (n = 11) coaches watched video of athletes sprinting at two different speeds while wearing eye tracking glasses and, retrospectively, reported on the technique features observed. Mixed methods ANOVAs were used to determine visual search strategies and efficiency and used to indicate the relationship between visual search and verbal commentary data. The speed of video playback was the main determinant of visual search behavior, significantly impacting the visual search rate and relative fixation duration at a number of areas of interest. The use of a visual pivot indicated all participants' visual search strategies were efficiency driven. Overall, the verbal commentary did not completely align with the eye tracking data and there were varying degrees of agreement with the identified technique related areas of interest for coaches and biomechanists. However, differences in visual search strategy and verbal commentary suggest that experiential knowledge impacts participants' observation and perception of sprinting technique.

Learner-adapted practice promotes skill transfer in unskilled adults learning the basketball set shot.

The current study used a complex, sport-specific movement skill to explore the effects of a win-shift/lose-stay practice schedule on learning and compared its effectiveness with that of blocked and random practice schedules. Thirty-six adults (24.9 ± 3.3 years) were assigned to blocked, random and learner-adapted training groups. Each participant performed 360 trials of the basketball set shot from multiple locations across six practice sessions. For the learner-adapted group, switching between task variations was performance-contingent; switching between shooting locations occurred only following a successful shot. Shooting success was calculated as the percentage of successful shots performed, and measured during pre-acquisition (i.e. baseline), acquisition (i.e. practice) and post-acquisition (i.e. retention and transfer). Despite scoring less shots throughout practice compared to baseline testing, the learner-adapted group showed a significant improvement for shooting success in transfer (d = 1.02). Blocked practice demonstrated significant improvements for shooting success in immediate retention (d = 1.83), delayed retention (d = 1.69) and transfer (d = 1.39). Random practice significantly improved shooting success in both immediate (d = 1.03) and delayed retention (d = 0.81). The current findings highlight that performance during practice does not necessarily represent the permanency and adaptability of skill learning. The implications of the findings and their practical applications are discussed in the context of practice scheduling during learning of a sports skill.

From the field of play to the laboratory: Recreating the demands of competition with augmented reality simulated sport.

Biomechanical analysis has typically been confined to a laboratory setting. While attempts have been made to take laboratory testing into the field, this study was designed to assess whether augmented reality (AR) could be used to bring the field into the laboratory. This study aimed to measure knee load in volleyball players through a jump task incorporating AR while maintaining the perception-action couplings by replicating the visual features of a volleyball court. Twelve male volleyball athletes completed four tasks: drop landing, hop jump, spike jump, and spike jump while wearing AR smart glasses. Biomechanical variables included patellar tendon force, knee moment and kinematics of the ankle, knee, hip, pelvis and thorax. The drop landing showed differences in patellar tendon force and knee moment when compared to the other conditions. The hop jump did not present differences in kinetics when compared to the spike conditions, instead of displaying the greatest kinematic differences. As a measure of patellar tendon loading the AR condition showed a close approximation to the spike jump, with no differences present when comparing landing forces and mechanics. Thus, AR may be used in a clinical assessment to better replicate information from the competitive environment.

Esports: The Chess of the 21st Century.

For many decades, researchers have explored the true potential of human achievement. The expertise field has come a long way since the early works of de Groot (1965) and Chase and Simon (1973). Since then, this inquiry has expanded into the areas of music, science, technology, sport, academia, and art. Despite the vast amount of research to date, the capability of study methodologies to truly capture the nature of expertise remains questionable. Some considerations include (i) the individual bias in the retrospective recall of developmental activities, (ii) the ability to develop ecologically valid tasks, and (iii) difficulties capturing the influence of confounding factors on expertise. This article proposes that expertise research in electronic sports (esports) presents an opportunity to overcome some of these considerations. Esports involves individuals or teams of players that compete in video game competitions via human-computer interaction. Advantages of applying the expert performance approach in esports include (i) developmental activities are objectively tracked and automatically logged online, (ii) the constraints of representative tasks correspond with the real-world environment of esports performance, and (iii) expertise has emerged without the influence of guided systematic training environments. Therefore, this article argues that esports research provides an ideal opportunity to further advance research on the development and assessment of human expertise.

Validation of a multidirectional locomotive dual-task paradigm to evaluate task-related differences in event-related electro-cortical activity.

A fundamental aspect of everyday function is the ability to simultaneously execute both cognitive and motor tasks. The ability to perform such tasks is commonly assessed using a dual-task paradigm that has the capacity to manipulate both cognitive and motor components of an action. Dual-task performance provides an opportunity to obtain an insight into how cognitive and motor function are affected during natural tasks (e.g., locomotion). The following study aimed to determine the effectiveness of using a goal-directed multidirectional locomotor task to measure differences in task-related (tasks of increasing difficulty) electro-cortical activity. In the single-task condition participants walked around a grid-based track, performing directional changes at each intersection in response to a sensory stimulus. In the dual-task condition participants performed the same primary task while performing a simultaneous memory recall task. Behavioural differences in trial completion time and electro-cortical activity were identified in relation to the posterior N2 and P3 component mean amplitudes. The results showed that, while performing a higher-level cognitive task during walking (dual-task), interference arises in a shared system that influences neural mechanisms involved in attention and selection for action, and later cognitive processes recruited in working memory and cognitive control. This study extends previous work and shows that performing a more complex cognitive task while walking, elicits interference effects sensitive to higher-level cognitive processes, and takes the next step towards measurement of electro-cortical activity within naturalistic environments.

Exploring the Effectiveness of Immersive Video for Training Decision-Making Capability in Elite, Youth Basketball Players.

Decision-making is an essential capability for success in team sport athletes. Good decision-making is underpinned by perceptual-cognitive skills that allow athletes to assess the environment and choose the correct choice from a number of alternatives. Previous research has demonstrated that decision-making can be trained "off-line" by exposing athletes to gameplay scenarios and having them make decisions based on the information presented to them. These scenarios are typically presented on television monitors or using life-size projections but recent advances in immersive video capabilities provide opportunities to improve the fidelity of training by presenting a realistic, 360° view of the competition environment. The purpose of this study was to assess the effectiveness of immersive video training and whether training would improve decision-making performance in elite, youth basketball players (male and female). A training group completed 10 or 12 immersive video (360° video presented in a head-mounted display) training sessions in which they viewed and responded to gameplay scenarios across 3-weeks while the control group only participated in their usual training routine. Performance was assessed on an immersive video test and during small-sided games (SSG). The male training group had a large, non-significant improvement on immersive test score (+4.0 points) and in the SSG (+5.8 points) compared to the male control group (+0.3 points and +1.0 points, respectively). While both the female control group (+9.7 points) and training group (7.4 points) had large improvements in the immersive training test, only the female control improved their performance in the SSG (+6.9 points). Despite the mixed findings, there may be benefit for using immersive video for training decision-making skill in team sports. The implications of these findings (e.g., gender of the actors used to create stimuli, variety of scenarios presented) and the limitations of the experiment are discussed.

Futsal task constraints promote transfer of passing skill to soccer task constraints.

This study investigated how learning a passing skill with futsal or soccer task constraints influenced transfer to a new task. Futsal (n = 24, 13.6 ± 1.2 years old, 7.0 ± 1.6 years of experience) and soccer (n = 24, 13.6 ± 1.2 years old, 6.8 ± 1.2 years of experience) players performed two 5v5 + goalkeeper modified games - a futsal-like task (small playing area with the futsal ball) and soccer-like task (large playing area with the soccer ball). Participants' passing accuracy and their orientation of attention were assessed during the two tasks. The futsal group improved their passing accuracy (ES = 0.75 ± 0.61) from the futsal-like to the soccer-like task, and they were more accurate than soccer players (ES = 2.98 ± 2.96). Conversely, the soccer group's passing accuracy remained stable across the two tasks (ES = 0.10 ± 0.52) and it was similar to the futsal group in the futsal-like task (ES = 0.58 ± 1.93). This indicates a higher magnitude of transfer (and adaptability) from performing passes in a small playing area with short time to act - futsal task constraints - to a larger playing area with longer time - soccer task constraints - than vice-versa. Furthermore, the futsal group showed a higher adaptation of attention orientation to the affordances that emerged with the soccer task constraints, which is suggested to be one of the main mechanisms promoting skill transfer. These results encourage soccer practitioners to introduce futsal task constraints to fast-track players' ability to functionally adapt perception-action coupling.

Modified perceptual training in sport: A new classification framework.

OBJECTIVES: To overview a framework that provides a theoretically-grounded approach to predicting the types of modified perceptual training tasks that will stimulate transfer of improved perceptual skills to sport performance environments. Modified perceptual training (MPT) collectively describes on- or off-field sports training tasks that are specifically designed to develop visual and perceptual-cognitive skill. Traditional training approaches in sport include sports vision training and perceptual-cognitive training, while recently, new technologies have enabled a broad range of additional MPT tools to become available to coaches and athletes. DESIGN: Short literature review and opinion article. METHODS: Literature in the fields of sports vision training and perceptual-cognitive training are summarised and contrasted. A selection of emerging MPT technologies are then overviewed. This leads to the identification of three interacting factors of MPT task design that may influence the task's capacity to transfer improved training performance to actual competition: (i) the targeted perceptual function, (ii) stimulus correspondence, and (iii) response correspondence, which are assimilated with key tenets of representative learning design. RESULTS: These three theoretically-grounded differences are adopted to support and justify the structure of the Modified Perceptual Training Framework which sets out predictions for future research to test in order to clarify the transfer effect of MPT tools. CONCLUSIONS: The application of the Modified Perceptual Training Framework may assist in future testing, design and selection of beneficial training tools in sport and as such, is predicted to have significant impact in empirical and practical settings.

Watch Where You're Going? Interferer Velocity and Visual Behavior Predicts Avoidance Strategy During Pedestrian Encounters.

Pedestrians can avoid collisions with other pedestrians by modifying some combination of their velocity and their path. The authors investigated how path constraints (constrained or unconstrained), interferer velocity (slow or fast), and vision (looking or not looking; time spent looking at the interferer) influenced collision avoidance to an oblivious interferer walking on a perpendicular path. Ten participants walked 6 m to either a point or line target on either a constrained or unconstrained path while wearing an eye-tracking device and avoiding an oblivious interferer that walked at 2 speeds. Looking behavior and interferer velocity were reliable predictors of determining whether a pedestrian would pass in front of or behind the interferer, while path constraints were less reliable. These findings highlight the degeneracy in human movement systems and suggest that, in complex environments, behavior may not always be optimized for efficiency.

Perception-action coupling in complex game play: Exploring the quiet eye in contested basketball jump shots.

The duration of the final fixation before movement initiation - a gaze strategy labelled quiet eye - has been found to explain differences in motor expertise and performance in precision tasks. To date, research only addressed this phenomenon in situations without adversarial constraints. In the present study, we compared the quiet-eye behaviour of intermediately-skilled and highly-skilled basketball players in defended vs. undefended game situations. We predicted differences in quiet-eye duration as a function of skill and performance particularly resulting from late quiet-eye offsets. Results indicated performance-enhancing effects of long quiet-eye durations in the defended but not in the undefended game situation. Furthermore, in line with our prediction, later quiet-eye offsets were associated with superior performance elucidating the phenomenon's relevance in online-demanding motor tasks. Further, earlier quiet-eye onsets were linked to successful performance supporting earlier suggestions that it is not only the duration but also the timing that matters. These findings not only extend the positive effects of the quiet eye in motor performance to dynamic game-play situations but also support the role of the quiet eye in response to programming and information processing respectively.

Long-term Practice with Domain-Specific Task Constraints Influences Perceptual Skills.

The long-term impact of practice with different task constraints on perceptual skill is relatively un-explored. This study examined the influence of extensive practice, i.e., more than a 1000 h of structured practice, with domain-specific task constraints on perceptual skill associated with the passing action. Despite performing the same passing skill, it is not known whether long-term exposure to specific soccer or futsal task constraints influences the players' attunement to environmental information. This study examined this issue by assessing the attention orientation of soccer (n = 24) and futsal players (n = 24) during modified games (6 vs. 6). Futsal players had higher scanning behavior during ball reception and control (40% more ball-player attention alternations) while soccer players mainly scanned the environment when not in ball possession (25% more attention alternations). We suggest that the behavioral differences found are elicited by the extensive domain-specific practice. That is, the higher number of players in soccer, and by a more intense game and easier to control ball in futsal. This study provides new insights into the long-term effects of practicing with specific task constraints.

Quiet eye predicts goaltender success in deflected ice hockey shots.

In interceptive timing tasks, long quiet eye (QE) durations at the release point, along with early tracking on the object, allow performers to couple their actions to the kinematics of their opponent and regulate their movements based on emergent information from the object's trajectory. We used a mobile eye tracker to record the QE of eight university-level ice hockey goaltenders of an equivalent skill level as they responded to shots that deflected off a board placed to their left or right, resulting in a trajectory with low predictability. QE behaviour was assessed using logistic regression and magnitude-based inference. We found that when QE onset occurred later in the shot (950 ± 580 ms, mean ± SD) there was an increase in the proportion of goals allowed (41% vs. 22%) compared to when QE onset occurred earlier. A shorter QE duration (1260 ± 630 ms) predicted a large increase in the proportion of goals scored (38% vs. 14%). More saves occurred when QE duration (2074 ± 47 ms) was longer. An earlier QE offset (2004 ± 66 ms) also resulted in a large increase in the number of goals allowed (37% vs. 11%) compared to a later offset (2132 ± 41 ms). Since an early, sustained QE duration contributed to a higher percentage of saves, it is important that coaches develop practice activities that challenge the goaltender's ability to fixate the puck early, as well as sustain a long QE fixation on the puck until after it is released from the stick.

The Effects of Either a Mirror, Internal or External Focus Instructions on Single and Multi-Joint Tasks.

Training in front of mirrors is common, yet little is known about how the use of mirrors effects muscle force production. Accordingly, we investigated how performing in front of a mirror influences performance in single and multi-joint tasks, and compared the mirror condition to the established performance effects of internal focus (IF) and external focus (EF) instructions in a two part experiment. In the single-joint experiment 28 resistance-trained participants (14 males and 14 females) completed two elbow flexion maximal voluntary isometric contractions under four conditions: mirror, IF, EF and neutral instructions. During these trials, surface EMG activity of the biceps and triceps were recorded. In the multi-joint experiment the same participants performed counter-movement jumps on a force plate under the same four conditions. Single-joint experiment: EF led to greater normalized force production compared to all conditions (P≤0.02, effect-size range [ES] = 0.46-1.31). No differences were observed between neutral and mirror conditions (P = 0.15, ES = 0.15), but both were greater than IF (P<0.01, ES = 0.79-1.84). Surface EMG activity was comparable across conditions (P≥0.1, ES = 0.10-0.21). Multi-joint experiment: Despite no statistical difference (P = 0.10), a moderate effect size was observed for jump height whereby EF was greater than IF (ES = 0.51). No differences were observed between neutral and mirror conditions (ES = 0.01), but both were greater than IF (ES = 0.20-22). The mirror condition led to superior performance compared to IF, inferior performance compared to EF, and was equal to a neutral condition in both tasks. These results provide novel and practical evidence concerning mirror training during resistance type training.

Cue informativeness constrains visual tracking during an interceptive timing task.

Interceptive actions, such as catching, are a fundamental component of many activities and require knowledge of advanced kinematic information and ball flight characteristics to achieve successful performance. Rather than combining these sources of information, recent exploration of interceptive actions has presented them individually. Thus, it still is unclear how the information available from advanced cues influences eye movement behaviour. By integrating advanced visual information with novel ball projection technology, this study examined how the availability of advanced information, using four different cueing conditions: no image (ball flight only with no advanced information), non-informative (ball flight coupled with ball release information), directional (ball flight coupled with directional information), and kinematic (ball flight coupled with video of a throwing action), influenced visual tracking during a one-handed catching task. The findings illustrated no differences in catching performance across conditions; however, tracking of the ball was initiated earlier, for a longer duration, and over a greater proportion of the ball's trajectory in the directional and kinematic conditions. Significant differences between a directional cue and kinematic cue were not evident, suggesting a simple cue that provided information on the time of release and direction of ball flight was sufficient for successfully anticipating ball release and constraining eye movements. These findings highlight the relationship between advanced information and gaze behaviour during ball flight, and the performance of dynamic interceptive actions. We discuss the implications and potential limitations (e.g. variability between throwing image and ball projection) of the findings in the context of recent research on catching.

A Combination of Amino Acids and Caffeine Enhances Sprint Running Capacity in a Hot, Hypoxic Environment.

Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport-specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions. Participants ingested one of four supplements: a double placebo, 3 mg.kg-1 body mass of caffeine + placebo, 2 x 7 g EAA (Musashi Create)+placebo, or caffeine + EAA before each exercise session using a randomized, double-blind crossover design. Electromyography (EMG) activity and quadriceps evoked responses to magnetic stimulation were assessed from the dominant leg at preexercise, halftime, and postexercise. Central activation ratio (CAR) was used to quantify completeness of quadriceps activation. Oxygenation of the prefrontal cortex was measured via near-infrared spectroscopy. Mean sprint work was higher (M = 174 J, 95% CI [23, 324], p < .05, d = 0.30; effect size, likely beneficial) in the caffeine + EAA condition versus EAAs alone. The decline in EMG activity was less (M = 13%, 95% CI [0, 26]; p < .01, d = 0.58, likely beneficial) in caffeine + EAA versus EAA alone. Similarly, the pre- to postexercise decrement in CAR was significantly less (M = -2.7%, 95% CI [0.4, 5.4]; p < .05, d = 0.50, likely beneficial) when caffeine + EAA were ingested compared with placebo. Cerebral oxygenation was lower (M = -5.6%, 95% CI [1.0, 10.1]; p < .01, d = 0.60, very likely beneficial) in the caffeine + EAA condition compared with LNAA alone. Co-ingestion of caffeine and EAA appears to maintain muscle activation and central drive, with a small improvement in running performance.

How can novel task constraints be used to induce acute changes in gaze behaviour?

Quiet eye (QE) is a robust phenomenon in golf putting and expert players frequently demonstrate longer QE periods (i.e., the final fixation prior to the onset of the putting motion) relative to their less-skilled counterparts. In this experiment we used a pre-test/post-test design to determine whether we could use novel training aids and instructions to elicit acute changes in QE behaviour after a brief intervention. Three techniques were used: a marker under the ball, a hole-focus instruction, and a novel putting device - the putting box of science (PBoS). We compared gaze behaviour before and after 30 practice putts and found significant changes in QE duration in the absence of concomitant changes in putting performance. The control (-18 ms) and PBoS (+198 ms) groups did not change, the hole-focus group (-287 ms) had a decrease in QE duration, and the marker group (+366 ms) increased in QE duration. These finding are discussed relative to current QE training programs and the implications for development of evidence-based training aids with coach consultation.

Kinematic and kinetic improvements associated with action observation facilitated learning of the power clean in Australian footballers.

This study investigated the effectiveness of action observation (AO) on facilitating learning of the power clean technique (kinematics) compared with traditional strength coaching methods and whether improvements in performance (kinetics) were associated with an improvement in lifting technique. Fifteen subjects (age, 20.9 ± 2.3 years) with no experience in performing the power clean exercise attended 12 training and testing sessions over a 4-week period. Subjects were assigned to 2 matched groups, based on preintervention power clean performance and performed 3 sets of 5 repetitions of the power clean exercise at each training session. Subjects in the traditional coaching group (TC; n = 7) received the standard coaching feedback (verbal cues and physical practice), whereas subjects in the AO group (n = 8) received similar verbal coaching cues and physical practice but also observed a video of a skilled model before performing each set. Kinematic data were collected from video recordings of subjects who were fitted with joint center markings during testing, whereas kinetic data were collected from a weightlifting analyzer attached to the barbell. Subjects were tested before intervention, at the end of weeks 2 and 3, and at after intervention at the end of week 4. Faster improvements (3%) were observed in power clean technique with AO-facilitated learning in the first week and performance improvements (mean peak power of the subject's 15 repetitions) over time were significant (p < 0.001). In addition, performance improvement was significantly associated (R = 0.215) with technique improvements. In conclusion, AO combined with verbal coaching and physical practice of the power clean exercise resulted in significantly faster technique improvements and improvement in performance compared with traditional coaching methods.

Effect of practice distribution and experience on the performance and retention of a discrete sport skill.

This study examined how practice distribution influenced performance and learning of a discrete sport skill, the Australian Football (AF) handball pass. A secondary aim was to assess whether previous experience playing competitive Australian Football influenced learning. Participants performed the handball 50 times (5 blocks x 10 repetitions) using either a massed (1 sec. between repetitions or distributed (30 sec. between repetitions) practice schedule. Testing consisted of pre-test, acquisition, immediate retention (10 min.), and delayed retention (2 weeks) sessions. Performance accuracy scores improved in the massed practice condition from pre-test to immediate retention and from pre-test to delayed retention. Likewise, performance improved in the distributed practice group from pretest to immediate retention, but scores were not different from pre-test to delayed retention, and decreased from immediate retention to delayed retention. While students with previous AF experience performed better overall, there were no differences between the massed and distributed groups based on experience. Results suggested that, regardless of previous related skill, massed practice of a discrete sport skill may lead to better retention of learning over a two-week period.