Temporal Occlusion Research Articles

The effect of task load, information reliability and interdependency on anticipation performance

In sport, coaches often explicitly provide athletes with stable contextual information related to opponent action preferences to enhance anticipation performance. This information can be dependent on, or independent of, dynamic contextual information that only emerges during the sequence of play (e.g. opponent positioning). The interdependency between contextual information sources, and the associated cognitive demands of integrating information sources during anticipation, has not yet been systematically examined. We used a temporal occlusion paradigm to alter the reliability of contextual and kinematic information during the early, mid- and final phases of a two-versus-two soccer anticipation task. A dual-task paradigm was incorporated to investigate the impact of task load on skilled soccer players’ ability to integrate information and update their judgements in each phase. Across conditions, participants received no contextual information (control) or stable contextual information (opponent preferences) that was dependent on, or independent of, dynamic contextual information (opponent positioning). As predicted, participants used reliable contextual and kinematic information to enhance anticipation. Further exploratory analysis suggested that increased task load detrimentally affected anticipation accuracy but only when both reliable contextual and kinematic information were available for integration in the final phase. This effect was observed irrespective of whether the stable contextual information was dependent on, or independent of, dynamic contextual information. Findings suggest that updating anticipatory judgements in the final phase of a sequence of play based on the integration of reliable contextual and kinematic information requires cognitive resources.

Early identification of the opposition shot taker characterises elite goalkeepers’ ability to read the game

ABSTRACT Researchers investigating expertise in soccer goalkeepers have overwhelmingly focused on anticipating penalty kicks and identifying kinematic cues that are used to anticipate action outcomes. In this study, we took a novel approach to exploring ‘game reading’ skills in soccer goalkeepers. Specifically, we investigated whether and by what point during an attacking sequence in open play, elite goalkeepers can identify the opposition shot taker, a skill that is likely to facilitate organisation of the defensive line and interception of forward creative attacking passes. We used a moving window temporal occlusion paradigm to present elite, sub-elite, and amateur goalkeepers with 11-vs-11 attacking sequences that were divided into progressive segments. After viewing each segment, participants identified the player they thought would shoot at goal at the end of the attacking sequence. Elite goalkeepers identified the opposition shot taker earlier and more accurately than sub-elite and amateur participants. Findings suggest that elite goalkeeping is underpinned not only by anticipation of action outcomes but also game-reading skill that enables identification of the player most likely to carry out those actions.

MICROBIAL CARIOGENIC FACTORS AND THE MECHANISMS OF THEIR COUNTERACTION IN THE ORAL FLUID OF CHILDREN AT EARLY AGE

Objective – to determine the balance between pro- and antibacterial agents influencingupon the development of a carious process in children at an early age.Materials and methods. 117 children 2-3 years of age were examined. Two observationgroups were formed depending on the condition of the hard dental tissues. І groupincluded 52 children without caries, group II– 65 children with caries. The oral hygieneof the children from the observation groups was assessed by means of Kuzmina EM index.Lysozyme activity in the oral fluid was studied by means of bacteriological method. sIgАcontent was determined by means of radial immunodiffusion method. Streptococcusmutans concentration in the oral fluid of children was determined by means of «SalivaCheck Mutans» set. All the manipulations were carried out after an informed consent ofparents was obtained.Results. Oral hygiene in children during the period of the temporal occlusion formationis found to be unsatisfactory – (0,48±0,20) points according to Kuzmina EM index. Thelevel of colonization of the oral cavity with Streptococcus mutans is high in 34,48 %of stomatologically healthy children and in 73,33 % of children with caries. Underconditions of caries process development, the main protective components in the oralfluid change. In particular, sIgA level 17,14 % increases concerning the index of healthychildren (р<0,05), and lysozyme activity 1,25 times decreases respectively (р<0,05).Conclusions. All the children examined present soft dental plaque, which is confirmedby the values of hygienic indices and levels of Streptococcus mutans concentration,which is reliably higher in children from group II. Under conditions of caries processdevelopment, changes of the major protective components of the oral cavity appear. Theypromote effective action of cariogenic factors.

Action prediction in psychosis

Aberrant motor-sensory predictive functions have been linked to symptoms of psychosis, particularly reduced attenuation of self-generated sensations and misattribution of self-generated actions. Building on the parallels between prediction of self- and other-generated actions, this study aims to investigate whether individuals with psychosis also demonstrate abnormal perceptions and predictions of others’ actions. Patients with psychosis and matched controls completed a two-alternative object size discrimination task. In each trial, they observed reaching actions towards a small and a large object, with varying levels of temporal occlusion ranging from 10% to 80% of movement duration. Their task was to predict the size of the object that would be grasped. We employed a novel analytic approach to examine how object size information was encoded and read out across progressive levels of occlusion with single-trial resolution. Patients with psychosis exhibited an overall pattern of reduced and discontinuous evidence integration relative to controls, characterized by a period of null integration up to 20% of movement duration, during which they did not read any size information. Surprisingly, this drop in accuracy in the initial integration period was not accompanied by a reduction in confidence. Difficulties in action prediction were correlated with the severity of negative symptoms and impaired functioning in social relationships.

Multi-view graph convolution network for the recognition of human action with spatial and temporal occlusion problems

Human action recognition holds great significance in the field of social security. However, the challenges posed by occlusion and changes in viewpoint create specific obstacles in achieving accurate recognition. In this study, we propose a multi-view graph convolution fusion method to effectively address this issue. Specifically, considering the limited availability of public human action datasets that include occlusion, we introduce an adaptive multi-view spatial–temporal occlusion generation method. It allows us to generate occlusion skeleton data from multiple viewpoints, ensuring a close resemblance to real-life scenarios with minimal modifications to existing public datasets. Additionally, we present a plug-and-play multi-view information fusion module, briefed as MGL, which aims to solve the occlusion problem. The MGL combines the capabilities of Graph Convolutional network (GCN) and Long Short-Term Memory network (LSTM), in which GCN is employed to reconstruct human skeleton information using multi-view spatial occlusion data, and LSTM captures the long-term dependencies within the temporal sequences of the multi-view data. Moreover, an attention mask mechanism is introduced to highlight key joint features. Experiment results illustrate the excellent performance of our method on the NTU RGB+D 60 and NTU RGB+D 120 datasets.

Timecourse of two-dimensional decision-making to offensive actions.

Decision-making is an important component in the perception-action coupling required for athletes to achieve fine performance. Signal detection theory (SDT) provides a means of quantifying athletes' decision-making processes, based on their ability to discriminate between different types of stimuli (sensitivity) and the locations of their response criteria along a decision axis in a given situation. Studies have shown differences in these two indices between athletes and less-experienced counterparts, although these studies were limited to unidimensional decision-making problems. In the present study, SDT analysis was applied to two-dimensional decision-making by volleyball players regarding their opponents' attacks, using a four-alternative forced-choice task combining judgments of the type (spike or tip) and direction (cross-court or down-the-line) of attacks. Furthermore, a temporal occlusion task was used to reveal the timecourses of changes in sensitivity and the location of response criteria relating to judgments of attack type and direction. There were three groups of participants, eight top-league players, ten collegiate players, and ten novices. The results showed clear effects of expertise and distinct timecourses for the two types of judgment. For the attack type judgments, the sensitivities of the top-league players were relatively low at the early occlusion points, and their response criteria were biased toward judging attacking actions as spikes. At the late occlusion points, their sensitivity peaked, and there was no bias in their response criteria. For the directional judgments, the sensitivity of the three groups improved as the occlusion point advanced, while their response criteria tended to become more similar, which was not the case for the attack type judgments. These results are discussed together with previous studies of volleyball players' decision-making and judgments regarding deceptive actions in sports.

Situational Analysis and Tactical Decision-Making in Elite Handball Players

Situational analysis and decision-making represent key elements of elite sports performances, but few studies have investigated which player’s skills related to these aspects are relevant in elite handballers. The aim of this study was to address differences among handballers belonging to two tiers in processing situational probabilities information related to offensive and defensive situations. A total of 38 handballers (male = 22, female = 16, age: 25.6 ± 6.5 years, first-tier = 11, second-tier = 27) saw videos about different offensive and defensive actions. According to the temporal occlusion paradigm, each handballer provided a response about the best action a selected player had to perform according to the game’s context. The time, accuracy, and technical correctness of each player’s response were assessed. MANOVA revealed moderate-to-high skills differences between first- and second-tier players. First-tier players provided higher scores in response time and accuracy; they also obtained higher technical correctness scores in the most complex situation. The members of the first tier seemed to mainly depend on the accuracy of responses, even if the technical correctness also resulted in a predictor in the most complex situation. Playing in the best tier seems to require the development of very good skills related to processing situational probability information; therefore, training these elements seems to be necessary for determining the differences among elite handballers.

The progressive use of visual cues in skilled adolescent cricket batters

AbstractThis study aims to investigate the visual anticipation of skilled adolescent cricket batters during a temporal occlusion task. Thirty skilled adolescent cricket batters were recruited for the study. A temporal occlusion paradigm was employed to allow participants to predict the swing and length of the delivery. A projected video was occluded at seven points during the delivery, with each subsequent point providing progressively more visual information. Skilled adolescent batters were not able to correctly anticipate the delivery without ball flight information. They required between 100 and 200 ms of ball flight to correctly perceive the delivery type above the level of chance. These findings have implications for the development of visual anticipation skills for children in striking sports.

Reliance Upon Contextual Information Can Impede Visual Anticipation

This study investigated whether skilled batsmen in a state cricket pathway could anticipate ball types when congruency of field-placings was manipulated with a bowler’s action. Twenty-four male cricket batsmen were recruited who had played either first-class cricket (n = 6), were part of under 17 (n = 8) or under 19 (n = 10) state cricket squads. Participants completed a video-based temporal occlusion test where they were required to anticipate ball types from a swing bowler. In condition one, contextual field-placing information was presented to be congruent with the delivery type and bowler’s action, whilst in condition two it was incongruent. Results did not reveal skill level differences across conditions for anticipation. In the congruent condition, all skill groups predicted above chance level at the beginning and end of the bowler’s delivery stride. In the incongruent condition, first-class players predicted above chance at the beginning of the bowler’s delivery stride, and to a higher magnitude above chance compared to other skill groups at ball release. Under 17 and 19 players could not predict above chance at the start of the bowler’s delivery stride with their magnitude of prediction lower than first-class players at ball release. Results indicate skilled batsmen find it challenging to integrate contextual and kinematic information to anticipate. This is likely due to greater emphasis placed upon contextual information in part supplied by data analysts. Findings have theoretical and practical implications respectively for lower body positioning for bat-ball interception and perceptual training to improve pick-up of kinematic cues. Highlights Skilled batsmen in a high-performance state cricket pathway could integrate congruent field-placings and bowler kinematics to anticipate ball types. First-class batsmen could integrate incongruent field-placing information to the start, but not the end, of the bowler’s delivery action to anticipate ball types. Under 17 and 19 batsmen could not integrate incongruent field-placings to bowler kinematic to anticipate ball types. Skilled batsmen who cannot use kinematic information to anticipate ball types should be given visual-perceptual simulation training to accelerate performance.

A developmental perspective on decision making in young soccer players: The role of executive functions

Lately, interest in both domain-specific and domain-general cognitive processes has increased as a means to explain soccer player expertise. While the two types of processes have mostly been studied separately, we sought to connect these lines of research by investigating the role of executive functions in soccer players’ decision making from a developmental perspective. As these cognitive processes as well as their relation might differ between age groups, we took a developmental perspective to better understand this link in a sample of N = 128 soccer players (Mage = 10.69 years, SD = 1.44). Two age groups (younger vs. older players) performed a video-based option-generation and decision-making task that used temporal occlusion. Additionally, executive functions were assessed with standardized computer-based tests. Results show a link between executive functions and sport-specific decision making, most prominent for working memory. Further, older players generated better options and showed better inhibition and cognitive flexibility than younger players. We suggest there is a crucial turning point in cognitive development around the age of 11 years.

Humans Can Track But Fail to Predict Accelerating Objects.

Objects in our visual environment often move unpredictably and can suddenly speed up or slow down. The ability to account for acceleration when interacting with moving objects can be critical for survival. Here, we investigate how human observers track an accelerating target with their eyes and predict its time of reappearance after a temporal occlusion by making an interceptive hand movement. Before occlusion, observers smoothly tracked the accelerating target with their eyes. At the time of occlusion, observers made a predictive saccade to the location where they subsequently intercepted the target with a quick pointing movement. We tested how observers integrated target motion information by comparing three alternative models that describe time-to-contact (TTC) based on the (1) final target velocity sample before occlusion, (2) average target velocity before occlusion, or (3) final target velocity and the rate of target acceleration. We show that observers were able to accurately track the accelerating target with visually-guided smooth pursuit eye movements. However, the timing of the predictive saccade and manual interception revealed inability to act on target acceleration when predicting TTC. Instead, interception timing was best described by the final velocity model that relies on extrapolating the last available target velocity sample before occlusion. Moreover, predictive saccades and manual interception showed similar insensitivity to target acceleration and were correlated on a trial-by-trial basis. These findings provide compelling evidence for the failure of integrating target acceleration into predictive models of target motion that drive both interceptive eye and hand movements.

A Bayesian computational model to investigate expert anticipation of a seemingly unpredictable ball bounce

During dynamic and time-constrained sporting tasks performers rely on both online perceptual information and prior contextual knowledge to make effective anticipatory judgments. It has been suggested that performers may integrate these sources of information in an approximately Bayesian fashion, by weighting available information sources according to their expected precision. In the present work, we extended Bayesian brain approaches to anticipation by using formal computational models to estimate how performers weighted different information sources when anticipating the bounce direction of a rugby ball. Both recreational (novice) and professional (expert) rugby players (n = 58) were asked to predict the bounce height of an oncoming rugby ball in a temporal occlusion paradigm. A computational model, based on a partially observable Markov decision process, was fitted to observed responses to estimate participants’ weighting of online sensory cues and prior beliefs about ball bounce height. The results showed that experts were more sensitive to online sensory information, but that neither experts nor novices relied heavily on prior beliefs about ball trajectories in this task. Experts, but not novices, were observed to down-weight priors in their anticipatory decisions as later and more precise visual cues emerged, as predicted by Bayesian and active inference accounts of perception.

Does anticipation of penalty kicks in soccer transfer across similar and dissimilar sports?

The aim of the present study was to examine whether anticipation skill associated with penalty-kick scenarios is sport-specific, or whether it transfers between sports that have similar elements. A shortened participation history questionnaire was used to identify 97 soccer players, 47 invasion sport players (e.g., rugby), and 72 other sport players (e.g., swimming), as well as skill level (hours of engagement/competition level). These participants completed a video-based temporal occlusion anticipation test that required them to select the destination of the ball across a series of soccer penalty scenarios. Results indicated that the skilled soccer players were more accurate than the skilled and less-skilled invasion sport players and skilled and less-skilled other sport players. Skilled soccer players were also more accurate than the less-skilled soccer players, with less-skilled soccer players exhibiting similar accuracy to both the skilled and less-skilled invasion sport and other sport players indicating that processes associated with anticipation of penalty kicks may be specific to their sport.

The Adverse Effect of Anxiety on Dynamic Anticipation Performance.

Anticipation is a crucial perceptual-cognitive skill in fast-ball sports, and the effect of high anxiety on performance has attracted more attention from sports psychologists. Related studies mainly focus on the effect of anxiety on influencing processing efficiency and attentional control (top-down vs. bottom-up) during information processing in sport. Attentional Control Theory (ACT) has been supported by several studies. However, these studies have been criticized by the low ecological validity of task design, such as neglecting the dynamic process of anticipation, and inadequate performance analysis, such as analyzing response accuracy and time separately. Using temporal occlusion paradigm, we tested ACT in a dynamic anticipation process. Eighteen skilled and eighteen less-skilled table tennis players were required to anticipate the serves of opponents under dynamic task constraints (early vs. late occlusion) and anxiety conditions (high vs. low anxiety). High cognitive state anxiety decreased processing efficiency (response time/response accuracy) for both groups whereas performance effectiveness (response accuracy) did not differ. In addition, it negatively affected processing efficiency in early anticipation compared with late anticipation tasks, suggesting that high cognitive state anxiety may have a greater impact on top-down attentional control. Our findings provide support for ACT and show that anxiety impairs anticipation efficiency and performance, possibly due to an ineffectively attentional shift from external kinematic cues to internal long-term working memory. Findings also have implications for the adaptation of attentional strategies and anxiolytic training.

Individual Differences and Transfer of Visual Anticipation in Expert Female Field Hockey Goalkeepers.

Visual anticipation is vital for performance in several domains such as driving, military, and high-speed interceptive sports, as it enables performers to handle severe time constraints. There has been little investigation into individual differences of anticipation skill transfer within a domain, which can guide training of anticipation to improve performance. The purpose of this study was to investigate individual differences in the transfer of anticipation within a domain, specifically anticipation of the field hockey penalty corner drag-flick across different opponents. Eight female Australian international and national field hockey goalkeepers participated. Goalkeepers completed female and male opponent penalty corner drag-flick temporal occlusion tests that presented contextual defensive runner positioning relative to the penalty spot, drag-flicker kinematics, and ball flight. Drag-flick movement time and ball velocity were significantly different across female and male opponents confirming that a transfer continuum existed. Five goalkeepers could transfer integration of runner contextual and drag-flicker kinematic information to anticipate loose runs above chance from female to male opponent tests. None of the goalkeepers could transfer integration of contextual and kinematic information for the tight runs across female to male opponents. An individual differences approach with truly expert performers provided unique insights into the mechanism of anticipation transfer within a domain. The findings of this study contribute to theoretical and applied knowledge, which can guide the training of anticipation skill to prepare individuals for superior performance.

Differences in expertise level for anticipatory skill between badminton ‘in game’ strokes and serves

Over the past decades, researchers in racquet sports have been testing the role of visual anticipation and expert attunement to essential kinematic information for responding to ‘in game’ strokes as well as serves. However, anticipatory behaviour to both strokes has not been compared directly, in spite of the different characteristics of these strokes in the context of badminton. Therefore, this study explored the differences in anticipatory behaviour among elite ( n = 26), competitive ( n = 15) and novices ( n = 17) between in game strokes and serves in badminton by use of lab based video temporal occlusion tests. In two separate blocks, last strokes (LS) and serves (S) were presented with different occlusion points (− 200 and − 100 ms before shuttle–racquet contact, at shuttle–racquet contact, and + 100 after shuttle–racquet contact) in a randomised order. The main results from the analysis of variance were that (a) elites generally showed faster and more accurate responses, and (b) responses were generally faster in LS conditions than in serves. These results add to the current body of knowledge on anticipatory behaviour in racquet sports, and the practical implications for coaching and training are discussed.

Effects of traditional and immersive video on anticipation in cricket: A temporal occlusion study

Traditional videos are frequently employed to assess anticipation within interceptive sports. However, there are limitations associated with traditional videos which impair the degree of correspondence between training interventions and competitive performances. Virtual reality (VR) head-mounted displays allow for the presentation of immersive videos in 360-degrees that might offer a more effective means by which to train athletes. Nonetheless, there is a paucity of research examining the efficacy of immersive videos in a cricket context. The main purpose of the present investigation was to compare batters’ ability to accurately predict the landing location of deliveries, and assess their confidence in such predictions, when viewing traditional and immersive videos. We also examined the degree to which delivery style (i.e., bowling machine, throwdowns, spin, and pace bowling) impacted prediction accuracy and confidence scores. Forty deliveries (i.e., 10 per style; occluded at 120 ms post-ball release) were presented to amateur cricketers (N = 18) in traditional and immersive video conditions. Participants were required to anticipate the landing location of the ball and rate their prediction confidence after each delivery. Analyses indicated a main effect of viewing condition that applied only to prediction. Participants predicted the landing location of the ball with the greatest accuracy in the immersive video footage condition. There was a main effect of delivery style for confidence only, with higher scores observed in the throwdown, spin, and pace conditions, when compared to the bowling machine. Given the increasing rate at which VR is becoming accessible, immersive videos should be considered by sport psychologists as an effective means by which to assess anticipation in cricket.

검도의 도구 사용 전문성에 따른 동작 예측과 대뇌 신경 활성화의 차이

Purpose: This study aimed to verify the difference between action anticipation and cortical neural activation for Kendo performance in the use of tools for professional kendo athlete and novice. Methods: Action anticipation tasks were performed on 15 kendo athletes and 15 novice group using temporal occlusion techniques. It is to accurately and quickly predict the final strike position by looking at the presented kendo strike videos (head, wrist and waist strike). In order to find out the differences in cortical neural activation according to action anticipation along with the task performance, motor-evoked potentials(MEPs) using TMS were measured. The dependent variables are predictive accuracy, response latency, and motor-evoked potentials, which are compared and analyzed between groups according to video length. Result: The analysis showed that the kendo athletes had an accurate and fast response latency compared to the novice. The comparison between groups according to video length was significantly accurate by the kendo athletes in sections 1 to 5, and was quickly performed by the kendo athletes in all video length conditions during the response latency time. In the comparison of the difference between the motor evoked potentials, kendo athletes were significantly higher in the 1st and 6th sections, and novice showed high cortical activation only in the 10th sections. Conclusion: As shown in the results, previous studies showed that kendo athletes’ excellent predictive abilities can also be seen in sports environments using tools, and behavioral predictive abilities are acquired through experience. The increased cortical activation of tool-use experts during behavior prediction demonstrated that mirror neurons do not simply follow motor matching between bodies, but also include movement of the tool, allowing mirror neural mechanisms to perform.

Reliability of Perceptual-Cognitive Skills in a Complex, Laboratory-Based Team-Sport Setting

The temporal occlusion paradigm is often used in anticipation and decision-making research in sports. Although it is considered as a valid measurement tool, evidence of its reproducibility is lacking but required for future cross-sectional and repeated-measures designs. Moreover, only a few studies on decision making in real-world environments exist. Here, we aimed at (a) implementing a temporal occlusion test with multi-dimensional motor response characteristics, and (b) assessing intra- and inter-session item reliability. Temporally occluded videos of attack sequences in a team handball scenario were created and combined with the SpeedCourt® contact plate system. Participants were instructed to perform pre-specified defensive actions in response to the video stimuli presented on a life-size projection screen. The intra- and inter-session (after at least 24 h) reproducibility of subjects’ motor responses were analyzed. Significant Cohen’s (0.44–0.54) and Fleiss’ (0.33–0.51) kappa statistics revealed moderate agreement of motor responses with the majority of attack situations in both intra- and inter-session analyses. Participants made faster choices with more visual information about the opponents’ unfolding action. Our findings indicate reliable decisions in a complex, near-game test environment for team handball players. The test provides a foundation for future temporal occlusion studies, including recommendations for new explanatory approaches in cognition research.

Perception and prediction of the putting distance of robot putting movements under different visual/viewing conditions.

The purpose of this paper is to examine, whether and under which conditions humans are able to predict the putting distance of a robotic device. Based on the “flash-lag effect” (FLE) it was expected that the prediction errors increase with increasing putting velocity. Furthermore, we hypothesized that the predictions are more accurate and more confident if human observers operate under full vision (F-RCHB) compared to either temporal occlusion (I-RCHB) or spatial occlusion (invisible ball, F-RHC, or club, F-B). In two experiments, 48 video sequences of putt movements performed by a BioRob robot arm were presented to thirty-nine students (age: 24.49±3.20 years). In the experiments, video sequences included six putting distances (1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 m; experiment 1) under full versus incomplete vision (F-RCHB versus I-RCHB) and three putting distances (2. 0, 3.0, and 4.0 m; experiment 2) under the four visual conditions (F-RCHB, I-RCHB, F-RCH, and F-B). After the presentation of each video sequence, the participants estimated the putting distance on a scale from 0 to 6 m and provided their confidence of prediction on a 5-point scale. Both experiments show comparable results for the respective dependent variables (error and confidence measures). The participants consistently overestimated the putting distance under the full vision conditions; however, the experiments did not show a pattern that was consistent with the FLE. Under the temporal occlusion condition, a prediction was not possible; rather a random estimation pattern was found around the centre of the prediction scale (3 m). Spatial occlusion did not affect errors and confidence of prediction. The experiments indicate that temporal constraints seem to be more critical than spatial constraints. The FLE may not apply to distance prediction compared to location estimation.