Understanding the role of gaze behaviour and coaching experience in the assessment of youth soccer teams

This study aimed to explore the perceptual-cognitive characteristics of coaches as they assessed team performance in youth soccer. The primary focus was to investigate the alignment between coaches' subjective analyses of team behaviour and objective analyses, while also examining the relationship between coaches' gaze behaviour and their levels of coaching experience, particularly considering the potential differences that may exist among coaches with varying levels of experience. Sixty-five male and female adults with various soccer coaching experience (experienced, novice, other team sport experience, and non-team sport experience) watched five 4-minute videos and assessed team behaviour. These subjective evaluations were compared to objective data obtained from video analysis and GPS, which included measures of completed skills, spatiotemporal characteristics, and passing networks. The participants' fixation duration and frequency were measured for each video clip, and the area around the ball specifically. The study found no significant differences between groups regarding the number of times participants' subjective analysis aligned with the objective data (p = 0.059, ɳ2 = 0.07). However, coaches with soccer coaching experience demonstrated a higher fixation frequency and more revisits to the ball area when compared to participants without soccer experience (p = <.001, ɳ2 = 0.09). The current study offers a unique approach to uncovering soccer coaching expertise by combining objective and subjective evaluations of team performance. In summary, the study reveals that coaching experience did not impact how often coaches subjective analyses matched objective data. However, soccer coaches had distinctive gaze behaviour patterns where they revisited the area around the ball more often.

Emotion category-modulated interpretation bias in perceiving ambiguous facial expressions

In contrast to prototypical facial expressions, we show less perceptual tolerance in perceiving vague expressions by demonstrating an interpretation bias, such as more frequent perception of anger or happiness when categorizing ambiguous expressions of angry and happy faces that are morphed in different proportions and displayed under high- or low-quality conditions. However, it remains unclear whether this interpretation bias is specific to emotion categories or reflects a general negativity versus positivity bias and whether the degree of this bias is affected by the valence or category of two morphed expressions. These questions were examined in two eye-tracking experiments by systematically manipulating expression ambiguity and image quality in fear- and sad-happiness faces (Experiment 1) and by directly comparing anger-, fear-, sadness-, and disgust-happiness expressions (Experiment 2). We found that increasing expression ambiguity and degrading image quality induced a general negativity versus positivity bias in expression categorization. The degree of negativity bias, the associated reaction time and face-viewing gaze allocation were further manipulated by different expression combinations. It seems that although we show a viewing condition-dependent bias in interpreting vague facial expressions that display valence-contradicting expressive cues, it appears that the perception of these ambiguous expressions is guided by a categorical process similar to that involved in perceiving prototypical expressions.

An examination of perceptual-motor recalibration in a 1-vs-1 anticipation test

This study examined the processes of perceptual-motor calibration/recalibration of defensive football players in a 1-vs-1 scenario. Ankle weights were used to reduce the acceleration capabilities of players performing an anticipation test, with the aim being to examine the player's response to the disturbance in terms of when movement was initiated and the impact on the mechanisms that underpinned anticipation, namely gaze behaviour. The ankle weights disturbed the perceptual-motor system and players initiated movement significantly earlier in the 1-vs-1 anticipation test. Analyses of perceptual-motor calibration/recalibration revealed that players acted closer to their maximal action capabilities prior to the addition of ankle weights, which negatively influenced the scaling of action capabilities. Moreover, players were unable to recalibrate whilst wearing ankle weights. However, following the withdrawal of the ankle weights, players were able to recalibrate within 11-15 trials. Players did not adapt gaze behaviour as a result of the disturbance being placed on the perceptual-motor system, but task familiarization resulted in more efficient eye movements. The results of this study show the importance of providing players the opportunity to "scale" action to perceptual information.

Facial expression modifies female body perception

The judgment of female body appearance has been reported to be affected by a range of internal (e.g., viewers' sexual cognition) and external factors (e.g., viewed clothing type and colour). This eye-tracking study aimed to complement previous research by examining the effect of facial expression on female body perception and associated body-viewing gaze behaviour. We presented female body images of Caucasian avatars in a continuum of common dress sizes posing seven basic facial expressions (neutral, happiness, sadness, anger, fear, surprise, and disgust), and asked both male and female participants to rate the perceived body attractiveness and body size. The analysis revealed an evident modulatory role of avatar facial expressions on body attractiveness and body size ratings, but not on the amount of viewing time directed at individual body features. Specifically, happy and angry avatars attracted the highest and lowest body attractiveness ratings, respectively, and fearful and surprised avatars tended to be rated slimmer. Interestingly, the impact of facial expression on female body assessment was not further influenced by viewers' gender, suggesting a 'universal' role of common facial expressions in modifying the perception of female body appearance.

Visual Behaviours of Expert Padel Athletes When Playing on Court: An In Situ Approach with a Portable Eye Tracker

Eye-tracking research has allowed the characterisation of gaze behaviours in some racket sports (e.g., tennis, badminton), both in controlled laboratory settings and in real-world scenarios. However, there are no studies about visual patterns displayed by athletes in padel.

METHOD

The aim of this exploratory case study was to address the visual behaviours of eight young expert padel athletes when playing match games on a padel court. Specifically, their gaze behaviours were examined with an in situ approach while returned trays/smashes, serves, and volleys were performed by their counterparts. Gaze patterns were registered with an SMI Eye Tracking Glasses 2 Wireless.

RESULTS

The participants' gaze was mainly focused on the ball-flight trajectory and on the upper body of the opponents because they were the two visual locations with a larger number of fixations and longer fixation time. No differences were found in these variables for each type of visual location when the three return situations were compared, or independently of them.

CONCLUSIONS

Padel players displayed a similar gaze behaviour during different representative return situations. This visual pattern was characterised by fixating at the ball and some opponents' upper kinematics (head, shoulders, trunk, and the region of arm-hand-racket) to perform real interceptive actions while playing against them on a padel court.

The Effects of Physiological Demands on Visual Search Behaviours During 2 vs. 1 + GK Game Situations in Football: An in-situ Approach

We examined the effect of physiological workload on gaze behaviour during defensive performance in 2 vs. 1 +goalkeeper game situations in football. Twenty-two players were assigned to either a high- or low-performing group based on a validated measure of tactical performance. A total of 12 game sequences (trials) were presented under high- and low-workload conditions. At the end of each sequence, participants were asked to indicate their perceived exertion using the Rating Scale of Mental Effort and the Borg Scale. The low- and high-workload conditions were defined when the players achieved 60 and 90% of their maximal heart rate, respectively, as per their performance in the Yo-Yo Intermittent Recovery Test. Visual search behaviours were recorded using Tobii Pro eye-movement registration glasses. Players reported higher rates of perceived exertion on the high- compared to low-workload condition. Participants in the low-performing group increased their average fixation duration and decreased the number of fixations and number of fixation locations from the low- to high-workload conditions. The low- and high-performing groups displayed different visual search strategies with regards the areas of interest fixated upon. Participants in the high-performing group focused on the SpaceFrontPlayer, followed by Ball, and AnotherOpponent. The low-performing group spent more time focusing on the SpaceFrontPlayer and SpacePlayer than Ball and AnotherOpponent. It appears that physiological workload and tactical expertise interact in constraining visual search behaviours in football players. Coaches and practitioners should consider ways to manipulate individual and task constraints while attending to the close interplay between physiological workload, visual behaviour, and tactical performance during practise.

Seeing a Talking Face Matters: The Relationship between Cortical Tracking of Continuous Auditory-Visual Speech and Gaze Behaviour in Infants, Children and Adults

An auditory-visual speech benefit, the benefit that visual speech cues bring to auditory speech perception, is experienced from early on in infancy and continues to be experienced to an increasing degree with age. While there is both behavioural and neurophysiological evidence for children and adults, only behavioural evidence exists for infants - as no neurophysiological study has provided a comprehensive examination of the auditory-visual speech benefit in infants. It is also surprising that most studies on auditory-visual speech benefit do not concurrently report looking behaviour especially since the auditory-visual speech benefit rests on the assumption that listeners attend to a speaker's talking face and that there are meaningful individual differences in looking behaviour. To address these gaps, we simultaneously recorded electroencephalographic (EEG) and eye-tracking data of 5-month-olds, 4-year-olds and adults as they were presented with a speaker in auditory-only (AO), visual-only (VO), and auditory-visual (AV) modes. Cortical tracking analyses that involved forward encoding models of the speech envelope revealed that there was an auditory-visual speech benefit [i.e., AV > (A+V)], evident in 5-month-olds and adults but not 4-year-olds. Examination of cortical tracking accuracy in relation to looking behaviour, showed that infants' relative attention to the speaker's mouth (vs. eyes) was positively correlated with cortical tracking accuracy of VO speech, whereas adults' attention to the display overall was negatively correlated with cortical tracking accuracy of VO speech. This study provides the first neurophysiological evidence of auditory-visual speech benefit in infants and our results suggest ways in which current models of speech processing can be fine-tuned.

Facial Expression Ambiguity and Face Image Quality Affect Differently on Expression Interpretation Bias

We often show an invariant or comparable recognition performance for perceiving prototypical facial expressions, such as happiness and anger, under different viewing settings. However, it is unclear to what extent the categorisation of ambiguous expressions and associated interpretation bias are invariant in degraded viewing conditions. In this exploratory eye-tracking study, we systematically manipulated both facial expression ambiguity (via morphing happy and angry expressions in different proportions) and face image clarity/quality (via manipulating image resolution) to measure participants' expression categorisation performance, perceived expression intensity, and associated face-viewing gaze distribution. Our analysis revealed that increasing facial expression ambiguity and decreasing face image quality induced the opposite direction of expression interpretation bias (negativity vs. positivity bias, or increased anger vs. increased happiness categorisation), the same direction of deterioration impact on rating expression intensity, and qualitatively different influence on face-viewing gaze allocation (decreased gaze at eyes but increased gaze at mouth vs. stronger central fixation bias). These novel findings suggest that in comparison with prototypical facial expressions, our visual system has less perceptual tolerance in processing ambiguous expressions which are subject to viewing condition-dependent interpretation bias.

Model-based estimation of the state of vehicle automation as derived from the driver's spontaneous visual strategies

When manually steering a car, the driver's visual perception of the driving scene and his or her motor actions to control the vehicle are closely linked. Since motor behaviour is no longer required in an automated vehicle, the sampling of the visual scene is affected. Autonomous driving typically results in less gaze being directed towards the road centre and a broader exploration of the driving scene, compared to manual driving. To examine the corollary of this situation, this study estimated the state of automation (manual or automated) on the basis of gaze behaviour. To do so, models based on partial least square regressions were computed by considering the gaze behaviour in multiple ways, using static indicators (percentage of time spent gazing at 13 areas of interests), dynamic indicators (transition matrices between areas) or both together. Analysis of the quality of predictions for the different models showed that the best result was obtained by considering both static and dynamic indicators. However, gaze dynamics played the most important role in distinguishing between manual and automated driving. This study may be relevant to the issue of driver monitoring in autonomous vehicles.

Age-related changes in gaze behaviour during social interaction: An eye-tracking study with an embodied conversational agent

Previous research has highlighted age-related differences in social perception, in particular emotional expression processing. To date, such studies have largely focused on approaches that use static emotional stimuli that the participant has to identify passively without the possibility of any interaction. In this study, we propose an interactive virtual environment to better address age-related variations in social and emotional perception. A group of 22 young (18-30 years) and 20 older (60-80 years) adults were engaged in a face-to-face conversation with an embodied conversational agent. Participants were invited to interact naturally with the agent and to identify his facial expression. Their gaze behaviour was captured by an eye-tracking device throughout the interaction. We also explored whether the Big Five personality traits (particularly extraversion) and anxiety modulated gaze during the social interaction. Findings suggested that age-related differences in gaze behaviour were only apparent when decoding social signals (i.e., listening to a partner's question, identifying facial expressions) and not when communicating social information (i.e., when speaking). Furthermore, higher extraversion levels consistently led to a shorter amount of time gazing towards the eyes, whereas higher anxiety levels led to slight modulations of gaze only when participants were listening to questions. Face-to-face conversation with virtual agents can provide a more naturalistic framework for the assessment of online socio-emotional interaction in older adults, which is not easily observable in classical offline paradigms. This study provides novel and important insights into the specific circumstances in which older adults may experience difficulties in social interactions.

Image Valence Modulates the Processing of Low-Resolution Affective Natural Scenes

In natural vision, noisy and distorted visual inputs often change our perceptual strategy in scene perception. However, it is unclear the extent to which the affective meaning embedded in the degraded natural scenes modulates our scene understanding and associated eye movements. In this eye-tracking experiment by presenting natural scene images with different categories and levels of emotional valence (high-positive, medium-positive, neutral/low-positive, medium-negative, and high-negative), we systematically investigated human participants' perceptual sensitivity (image valence categorization and arousal rating) and image-viewing gaze behaviour to the changes of image resolution. Our analysis revealed that reducing image resolution led to decreased valence recognition and arousal rating, decreased number of fixations in image-viewing but increased individual fixation duration, and stronger central fixation bias. Furthermore, these distortion effects were modulated by the scene valence with less deterioration impact on the valence categorization of negatively valenced scenes and on the gaze behaviour in viewing of high emotionally charged (high-positive and high-negative) scenes. It seems that our visual system shows a valence-modulated susceptibility to the image distortions in scene perception.

Enhanced Associations With Actions of the Artist Influence Gaze Behaviour

The aesthetic experience of the perceiver of art has been suggested to relate to the art-making process of the artist. The artist's gestures during the creation process have been stated to influence the perceiver's art-viewing experience. However, limited studies explore the art-viewing experience in relation to the creative process of the artist. We introduced eye-tracking measures to further establish how congruent actions with the artist influence perceiver's gaze behaviour. Experiments 1 and 2 showed that simultaneous congruent and incongruent actions do not influence gaze behaviour. However, brushstroke paintings were found to be more pleasing than pointillism paintings. In Experiment 3, participants were trained to associate painting actions with hand primes to enhance visuomotor and visuovisual associations with the artist's actions. A greater amount of time was spent fixating brushstroke paintings when presented with a congruent prime compared with an incongruent prime, and fewer fixations were made to these styles of paintings when presented with an incongruent prime. The results suggest that explicit links that allow perceivers to resonate with the artist's actions lead to greater exploration of preferred artwork styles.

Clinicians' gaze behaviour in simulated paediatric emergencies

AIM

Differences in the gaze behaviour of experts and novices are described in aviation and surgery. This study sought to describe the gaze behaviour of clinicians from different training backgrounds during a simulated paediatric emergency.

METHODS

Clinicians from four clinical areas undertook a simulated emergency. Participants wore SMI (SensoMotoric Instruments) eye tracking glasses. We measured the fixation count and dwell time on predefined areas of interest and the time taken to key clinical interventions.

RESULTS

Paediatric intensive care unit (PICU) consultants performed best and focused longer on the chest and airway. Paediatric consultants and trainees spent longer looking at the defibrillator and algorithm (51 180 ms and 50 551 ms, respectively) than the PICU and paediatric emergency medicine consultants.

CONCLUSIONS

This study is the first to describe differences in the gaze behaviour between experts and novices in a resuscitation. They mirror those described in aviation and surgery. Further research is needed to evaluate the potential use of eye tracking as an educational tool.

Factors contributing to individual differences in facial expression categorisation

Individuals vary in perceptual accuracy when categorising facial expressions, yet it is unclear how these individual differences in non-clinical population are related to cognitive processing stages at facial information acquisition and interpretation. We tested 104 healthy adults in a facial expression categorisation task, and correlated their categorisation accuracy with face-viewing gaze allocation and personal traits assessed with Autism Quotient, anxiety inventory and Self-Monitoring Scale. The gaze allocation had limited but emotion-specific impact on categorising expressions. Specifically, longer gaze at the eyes and nose regions were coupled with more accurate categorisation of disgust and sad expressions, respectively. Regarding trait measurements, higher autistic score was coupled with better recognition of sad but worse recognition of anger expressions, and contributed to categorisation bias towards sad expressions; whereas higher anxiety level was associated with greater categorisation accuracy across all expressions and with increased tendency of gazing at the nose region. It seems that both anxiety and autistic-like traits were associated with individual variation in expression categorisation, but this association is not necessarily mediated by variation in gaze allocation at expression-specific local facial regions. The results suggest that both facial information acquisition and interpretation capabilities contribute to individual differences in expression categorisation within non-clinical populations.

Measuring dwell time percentage from head-mounted eye-tracking data--comparison of a frame-by-frame and a fixation-by-fixation analysis

Although analysing software for eye-tracking data has significantly improved in the past decades, the analysis of gaze behaviour recorded with head-mounted devices is still challenging and time-consuming. Therefore, new methods have to be tested to reduce the analysis workload while maintaining accuracy and reliability. In this article, dwell time percentages to six areas of interest (AOIs), of six participants cycling on four different roads, were analysed both frame-by-frame and in a 'fixation-by-fixation' manner. The fixation-based method is similar to the classic frame-by-frame method but instead of assigning frames, fixations are assigned to one of the AOIs. Although some considerable differences were found between the two methods, a Pearson correlation of 0.930 points out a good validity of the fixation-by-fixation method. For the analysis of gaze behaviour over an extended period of time, the fixation-based approach is a valuable and time-saving alternative for the classic frame-by-frame analysis.

A novel video-based paradigm to study the mechanisms underlying age- and falls risk-related differences in gaze behaviour during walking

PURPOSE

The current study aimed to quantitatively assess differences in gaze behaviour between participants grouped on the basis of their age and measures of functional mobility during a virtual walking paradigm.

METHODS

The gaze behaviour of nine young adults, seven older adults with a relatively low risk of falling and seven older adults with a relatively higher risk of falling was measured while they watched five first-person perspective movies representing the viewpoint of a pedestrian walking through various environments. Participants also completed a number of cognitive tests: Stroop task, visual search, trail making task, Mini Mental Status Examination, and reaction time, visual tests (visual acuity and contrast sensitivity) and assessments of balance (Activities Balance Confidence Scale and Berg Balance Scale) to aid in the interpretation of differences in gaze behaviour.

RESULTS

The high risk older adult group spent significantly more time fixating aspects of the travel path than the low risk and young adult groups. High risk older adults were also significantly slower in performing a number of the cognitive tasks than young adults. Correlations were conducted to compare the extent to which travel path fixation durations co-varied with scores on the tests of visual search, motor, and cognitive function. A positive significant correlation was found between the speed of response to the incongruent Stroop task and travel path fixation duration r21  = 0.44, p < 0.05.

CONCLUSIONS

The results indicate that our movie-viewing paradigm can identify differences in gaze behaviour between participants grouped on the basis of their age and measures of functional mobility and that these differences are associated with cognitive decline.

The role of observers' gaze behaviour when watching object manipulation tasks: predicting and evaluating the consequences of action

When watching an actor manipulate objects, observers, like the actor, naturally direct their gaze to each object as the hand approaches and typically maintain gaze on the object until the hand departs. Here, we probed the function of observers' eye movements, focusing on two possibilities: (i) that observers' gaze behaviour arises from processes involved in the prediction of the target object of the actor's reaching movement and (ii) that this gaze behaviour supports the evaluation of mechanical events that arise from interactions between the actor's hand and objects. Observers watched an actor reach for and lift one of two presented objects. The observers' task was either to predict the target object or judge its weight. Proactive gaze behaviour, similar to that seen in self-guided action-observation, was seen in the weight judgement task, which requires evaluating mechanical events associated with lifting, but not in the target prediction task. We submit that an important function of gaze behaviour in self-guided action observation is the evaluation of mechanical events associated with interactions between the hand and object. By comparing predicted and actual mechanical events, observers, like actors, can gain knowledge about the world, including information about objects they may subsequently act upon.