Foveal and Peripheral Fields of Vision Influences Perceptual Skill in Anticipating Opponents’ Attacking Position in Volleyball

Viewing angle, skill level and task representativeness affect response times in basketball defence

In basketball defence, it is impossible to keep track of all players without peripheral vision. This is the first study to investigate peripheral vision usage in an experimentally controlled setup, with sport-specific basketball stimuli from a first-person perspective, large viewing eccentricities (up to 90° to the left and right), and natural action responses. A CAVE and a motion-tracking system was used to project the scenarios and capture movement responses of high- and low-skilled basketball players, respectively. Four video conditions were created: (1) a simple reaction time task without crowding (only attackers), (2) a simple reaction time task with crowding (with attackers and defenders), (3) a choice-reaction time task where the player cutting to the basket eventually passed the ball to another player and (4) a game simulation. The results indicated eccentricity effects in all tests, a crowding effect in condition 2, and expertise differences in conditions 3 and 4 only. These findings suggest that viewing eccentricity has an impact on response times, that crowding is a limiting factor for peripheral perception in sports games, and that high-skilled but not low-skilled players can compensate for eccentricity effects in real game situations, indicating their superior positioning and perceptual strategies.

Identification of "sleeping" talent using psychological characteristics in junior elite ice-hockey players

Scouts search for "sleepers" who may be initially overlooked but ultimately exceed expectations. The psychological characteristics of those players are often neglected because they are difficult to observe, but hold promise to identify sleepers given for example the self-regulation and perceptual-cognitive skills that those developing players might need to flourish. The aim of this study was to examine whether sleepers could be retrospectively identified using psychological characteristics. Ninety-five junior elite ice-hockey players (aged 15-16) were assessed on self-regulation and perceptual-cognitive skills before the yearly draft. Seventy players were drafted after the second round (37^th or later). Three years later, professional scouts identified 15/70 sleepers they would now pick if given the chance. Those identified by the scouts showed higher self-regulation planning, and had distinguishable gaze behaviour (fewer fixations on more AOIs) when performing a video-based decision-making task than other late-drafted players (84.3% correct classification; R² = .40). In addition, two latent profiles differentiated by self-regulation were found, with the profile with higher scores including 14/15 players selected by the scouts. Psychological characteristics were successful in retrospectively predicting sleepers, and may in future help scouts to make better selections of talent.

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.

Earlier detection facilitates skilled responses to deceptive actions

High-skilled and recreational rugby players were placed in a semi-immersive CAREN Lab environment to examine susceptibility to, and detection of, deception. To achieve this, a broad window of seven occlusion times was used in which participants responded to life-size video clips of an opposing player 'cutting' left or right, with or without a deceptive sidestep. Participants made full-body responses to 'intercept' the player and gave a verbal judgement of the opponent's final running direction. Response kinematic and kinetic data were recorded using three-dimensional motion capture cameras and force plates, respectively. Based on response accuracy, the results were separated into deception susceptibility and deception detection windows then signal detection analysis was used to calculate indices of discriminability between genuine and deceptive actions (d') and judgement bias (c). Analysis revealed that high-skilled and low-skilled players were similarly susceptible to deception; however, high-skilled players detected deception earlier in the action sequence, which enabled them to make more effective behavioural responses to deceptive actions.

Time is body: Multimodal evidence of crosstalk between interoception and time estimation

Theoretical approaches propose a blending between interoception and time estimation. Interoception might constitute a neurophysiological mechanism for encoding duration. However, no study has assessed the convergence between interoception and time estimation using behavioral, neurophysiological, and functional anatomy signatures. We examined the multimodal convergence between interoception and time estimation using a two-fold approach. In study 1, we developed a dual design combining interoception (measuring heartbeat detection - HBD, and heartbeat evoked potential - HEP) with a time estimation paradigm (TEP, estimation of duration of a 120 s interval). In study 2, we performed a conjoint metanalysis (Multi-level Kernel Density Analysis, MKDA) of neuroimaging, including reports of interoception and time estimation. Both studies provide convergent evidence of time estimation's significant involvement in behavioral, electrophysiological (enhanced HEP), and neuroimaging (overlapping cluster in the right insula and operculum) signatures of interoception. Convergent results from both studies offer direct support for a shared mechanism of interoception and time estimation.

On the Influence of Action Preference on Female Players' Gaze Behavior During Defense of Volleyball Attacks

Knowledge of an opponent's action preference may affect visual anticipation of their action outcome. Specifically, if an opponent acts according to their purported preference, anticipation may be facilitated. Conversely, if an opponent does not act according to their purported preference, anticipation may be unaffected or even harmed. The underlying perceptual-cognitive mechanisms of that effect, however, remain unclear. Here we tested the hypothesis that players might change their gaze behavior once provided with preference information. To this end, 27 female volleyball players anticipated the direction of attacks in two test blocks with 40 videos each. Videos were shown on a large screen and stopped 240 ms prior to hand-ball-contact. Participants simulated defensive reaction while their gaze was recorded using a mobile eye-tracker. One female attacker directed 75% of shots diagonally (25% longline), while another female attacker distributed shots equally to both directions. After block one, half of the participants were informed that either both attackers preferred diagonal shots in 75% of occasions (group preferred) or that both attackers distributed shots equally across directions (group non-preferred). Analysis of decision behavior (i.e., proportion of diagonal decisions), but not prediction accuracy (i.e., proportion of correct predictions), revealed that those instructions led both groups decide differently according to the purported preferences from block 1 to block 2. Analysis of gaze behavior did not reveal group-specific effects across blocks or attackers with/-out action preference. Findings underline the influence of contextual information on anticipation, but they leave open whether the availability of contextual information similarly affects gaze behavior.

Seeing the Bigger Picture: Susceptibility to, and Detection of, Deception

An extended time window was used to examine susceptibility to, and detection of, deception in rugby union. High- and low-skilled rugby players judged the final running direction of an opponent "cutting" left or right, with or without a deceptive sidestep. Each trial was occluded at one of eight time points relative to the footfall after the initial (genuine or fake) reorientation. Based on response accuracy, the results were separated into deception susceptibility and deception detection windows. Signal-detection analysis was used to calculate the discriminability of genuine and deceptive actions (d') and the response bias (c). High-skilled players were less susceptible to deception and better able to detect when they had been deceived, accompanied by a reduced bias toward perceiving all actions as genuine. By establishing the time window in which players become deceived, it will now be possible to identify the kinematic sources that drive deception.

Decision-making and dynamics of eye movements in volleyball experts

Key decision-makers among experts in a given field can sometimes be identified based on their role and responsibilities. The aim of the study is to compare perceptual-cognitive skills of experts with decisional responsibilities (setters in volleyball) with that of other volleyball experts. Eighty-two participants (26 setters, 36 other players and 20 controls) viewed 50 volleyball video sequences. Sequences stopped 120 ms before ball contact and participants, whose eye movements were recorded, had to predict the ball direction. Generalized Estimating Equations analysis revealed that setters and controls made more but shorter fixations than other players. However, both expert groups made better predictions than controls. Dynamics analyses of eye movements over time show that, right before ball contact, opposing players’ upper body is a most relevant attentional cue in all game situations. Results are discussed in terms of decision-making responsibilities to identify key decision-makers in volleyball and in general. They point towards specific perceptual-cognitive abilities found in setters and support the idea that they constitute a subgroup of experts, but that they are not “better” than other players in anticipating the game.

Periphere Wahrnehmung im Sport

Zusammenfassung. Die periphere Wahrnehmung im Sport ist eine theoretische wie methodische Herausforderung. Während die bisher in der Literatur diskutierten Funktionalitäten des gleichzeitigen peripheren Monitorings mehrerer Objekte, der Detektion von peripheren Bewegungsveränderungen und der peripheren Preview-Funktion zur Planung von Blicksprüngen gut begründet scheinen, fehlte bislang deren eindeutiger empirischer Nachweis. Mit Hilfe des Multiple-Objekt-Tracking-Paradigmas konnten die beiden erstgenannten Funktionalitäten empirisch untermauert und in diesem Zuge zu berücksichtigende visuelle und aufmerksamkeitsbedingte Randbedingungen bestimmt werden. In einem weiteren Schritt wurden die neu eingeführten Begriffe Anker, Pivot und Spot mit den gefundenen Funktionalitäten in Beziehung gesetzt. Abschließend wurden konkrete Vorhersagen für sportspezifische Untersuchungen formuliert, um die so umschriebenen Funktionalitäten empirisch zu überprüfen. Die Ergebnisse solcher Untersuchungen werden zeigen, inwieweit sich die grundlagenwissenschaftlichen Befunde auf Belange des Sports transferieren lassen. Für die Sportpraxis könnte es dabei ein wichtiges Ziel sein, ein funktional begründetes Blick- und Aufmerksamkeitstraining zu integrieren, um das volle Potenzial der peripheren Wahrnehmung auszuschöpfen.

Effect of Skill Level on Allocation of Visual Attention in Volleyball Blocking

Dynamic motor skills such as volleyball blocking rely on efficient perception–action coupling and are influenced by individual, environmental, and task constraints. However, limited research studies have assessed the effect of an individual constraint such as blocking skill on visual attention during an in-situ volleyball blocking task. Therefore, this study used a cross-sectional, observational design to investigate the gaze behavior of 18 male volleyball players (25.6 ± 4.9 years), of two different levels of blocking skill determined a priori according to success during an on-court blocking task. When compared to relatively unsuccessful players (RUS), the gaze of relatively successful players (RS) was observed to fixate more often (RUS: 0.7 ± 0.7 n, RS: 1.3 ± 0.3 n) and dwell for longer (Total; RUS: 12.2 ± 18.4%, RS: 48.0 ± 37.2%, Phase 4; RUS: 6.6 ± 8.8%, RS: 16.9 ± 12.4%) on the opposition spiker, demonstrating that important perceptual information about an opposing team’s attack lies within the behavior of the opposition spiker. More successful blockers were also observed to be taller (RUS: 181.8 ± 6.6 cm, RS: 192.6 ± 3.9 cm), longer in arm-span (RUS: 185.7 ± 5.6 cm, RS: 195.2 ± 5.6 cm), and heavier (RUS: 78.6 ± 11.4 kg, RS: 90.5 ± 8.5 kg). These results can consequently be used to develop a profile of the visual attention and physical attributes of successful blockers for use in developing talented players.

The Sport Expert's Attention Superiority on Skill-related Scene Dynamic by the Activation of left Medial Frontal Gyrus: An ERP and LORETA Study

Extensive studies have shown that a sports expert is superior to a sports novice in visually perceptual-cognitive processes of sports scene information, however the attentional and neural basis of it has not been thoroughly explored. The present study examined whether a sport expert has the attentional superiority on scene information relevant to his/her sport skill, and explored what factor drives this superiority. To address this problem, EEGs were recorded as participants passively viewed sport scenes (tennis vs. non-tennis) and negative emotional faces in the context of a visual attention task, where the pictures of sport scenes or of negative emotional faces randomly followed the pictures with overlapping sport scenes and negative emotional faces. ERP results showed that for experts, the evoked potential of attentional competition elicited by the overlap of tennis scene was significantly larger than that evoked by the overlap of non-tennis scene, while this effect was absent for novices. The LORETA showed that the experts' left medial frontal gyrus (MFG) cortex was significantly more active as compared to the right MFG when processing the overlap of tennis scene, but the lateralization effect was not significant in novices. Those results indicate that experts have attentional superiority on skill-related scene information, despite intruding the scene through negative emotional faces that are prone to cause negativity bias toward their visual field as a strong distractor. This superiority is actuated by the activation of left MFG cortex and probably due to self-reference.

Eye-Tracking Technology and the Dynamics of Natural Gaze Behavior in Sports: A Systematic Review of 40 Years of Research

Reviewing 60 studies on natural gaze behavior in sports, it becomes clear that, over the last 40 years, the use of eye-tracking devices has considerably increased. Specifically, this review reveals the large variance of methods applied, analyses performed, and measures derived within the field. The results of sub-sample analyses suggest that sports-related eye-tracking research strives, on the one hand, for ecologically valid test settings (i.e., viewing conditions and response modes), while on the other, for experimental control along with high measurement accuracy (i.e., controlled test conditions with high-frequency eye-trackers linked to algorithmic analyses). To meet both demands, some promising compromises of methodological solutions have been proposed—in particular, the integration of robust mobile eye-trackers in motion-capture systems. However, as the fundamental trade-off between laboratory and field research cannot be solved by technological means, researchers need to carefully weigh the arguments for one or the other approach by accounting for the respective consequences. Nevertheless, for future research on dynamic gaze behavior in sports, further development of the current mobile eye-tracking methodology seems highly advisable to allow for the acquisition and algorithmic analyses of larger amounts of gaze-data and further, to increase the explanatory power of the derived results.

Effects of Video-Based Visual Training on Decision-Making and Reactive Agility in Adolescent Football Players

This study investigated the trainability of decision-making and reactive agility via video-based visual training in young athletes. Thirty-four members of a national football academy (age: 14.4 ± 0.1 years) were randomly assigned to a training (VIS; n = 18) or a control group (CON; n = 16). In addition to the football training, the VIS completed a video-based visual training twice a week over a period of six weeks during the competition phase. Using the temporal occlusion technique, the players were instructed to react on one-on-one situations shown in 40 videos. The number of successful decisions and the response time were measured with a video-based test. In addition, the reactive-agility sprint test was used. VIS significantly improved the number of successful decisions (22.2 ± 3.6 s vs. 29.8 ± 4.5 s; p < 0.001), response time (0.41 ± 0.10 s vs. 0.31 ± 0.10 s; p = 0.006) and reactive agility (2.22 ± 0.33 s vs. 1.94 ± 0.11 s; p = 0.001) pre- vs. post-training. No significant differences were found for CON. The results have shown that video-based visual training improves the time to make decisions as well as reactive agility sprint-time, accompanied by an increase in successful decisions. It remains to be shown whether or not such training can improve simulated or actual game performance.

Ghost-in-the-Machine reveals human social signals for human-robot interaction

We used a new method called "Ghost-in-the-Machine" (GiM) to investigate social interactions with a robotic bartender taking orders for drinks and serving them. Using the GiM paradigm allowed us to identify how human participants recognize the intentions of customers on the basis of the output of the robotic recognizers. Specifically, we measured which recognizer modalities (e.g., speech, the distance to the bar) were relevant at different stages of the interaction. This provided insights into human social behavior necessary for the development of socially competent robots. When initiating the drink-order interaction, the most important recognizers were those based on computer vision. When drink orders were being placed, however, the most important information source was the speech recognition. Interestingly, the participants used only a subset of the available information, focussing only on a few relevant recognizers while ignoring others. This reduced the risk of acting on erroneous sensor data and enabled them to complete service interactions more swiftly than a robot using all available sensor data. We also investigated socially appropriate response strategies. In their responses, the participants preferred to use the same modality as the customer's requests, e.g., they tended to respond verbally to verbal requests. Also, they added redundancy to their responses, for instance by using echo questions. We argue that incorporating the social strategies discovered with the GiM paradigm in multimodal grammars of human-robot interactions improves the robustness and the ease-of-use of these interactions, and therefore provides a smoother user experience.

Visuospatial Attention and Motor Skills in Kung Fu Athletes

The present study compared the performance of a group of sixteen kung fu athletes with that of a control group of fourteen nonathletes on a speeded visuospatial task and a hand-tapping motor task. In the visuospatial task the results showed that athletes were faster than the control participants when stimuli were presented at the periphery of the visual field at a middle and high presentation speed with short interstimulus intervals. Athletes were also significantly faster than nonathlete participants when performing motor actions such as hand-tapping with their dominant hand but groups did not differ with the nondominant hand. These results support the view that athletes perform some speeded visuospatial and motor tasks faster than nonathletes under certain conditions. The findings suggest that, after several years of practice, kung fu athletes develop certain skills that allow them to perform motor speed maneuvers under time pressure conditions.