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Earlier detection facilitates skilled responses to deceptive actions
Abstract
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.
... Recently, Jackson and his colleagues combined SDT analysis with a temporal occlusion method to analyze the dynamic characteristics of the sensitivity and response criteria locations of expert players when discriminating between opponents' genuine and fake actions (Jackson et al. 2018;Warren-West and Jackson 2020;Warren-Westgate et al. 2021). One of their intriguing findings was the identification of two time windows for players to anticipate deception, which they named the deception susceptibility and deception detection windows (Warren-West and Jackson 2020). ...
... This is represented by a steeper increase in sensitivity and weakening of bias compared with lessskilled players. The response mode also influences the expert advantage in these windows to some extent (Warren-Westgate et al. 2021). ...
... We used mouse clicks for practical reasons: we needed to conduct the parts of the experiment involving the Expert players at their training site, which was very remote from our laboratory, so it would have been very difficult, if not impossible, to move and setup equipment for precisely recording their actions during the experiment at their training site. While the present study showed clear effects of expertise using mouse clicks, and some studies have demonstrated consistent results between sport-specific and generic responses (Brault et al. 2012;Warren-Westgate et al. 2021), its findings need to be examined using ecologically valid response modes for volleyball in future studies. ...
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.
... Many researchers have employed the temporal occlusion paradigm to reveal the timecourse of the expert advantage in judging the outcome of deceptive actions (Brault, et al., 2012;Güldenpenning et al., 2013;Huys et al., 2009;Jackson et al., 2018;Jackson et al., 2020;Kunde et al., 2011;Mori & Shimada, 2013;Park et al., 2019;Rowe et al., 2009;Sebanz & Shiffrar, 2009;Warren-West & Jackson, 2020;Warren-Westgate et al., 2021). In most of these studies, researchers made inferences about the kinematic sources that convey deceptive intent and those used to detect deception. ...
... The findings from the present study have implications for coaching practice. Rugby coaching dictum encourages players to focus on the hips of an opponent to determine their direction of travel as they "don't tell lies" (Hickie & Donaldson, 2015, p. 172) and research has demonstrated that expert rugby players fixate more on central areas of the body (abdomen and hips), in comparison to their less-skilled counterparts (Mori & Shimada, 2013;Warren-West & Jackson, 2020;Warren-Westgate et al., 2021). Despite this, we found minimal differences between pelvis yaw and lower trunk displacement in genuine and deceptive actions until after the initial reorientation; a finding also reported by Brault et al. (2010). ...
... Both the original recordings and choice of time of occlusion can be closely controlled and manipulated with precision. While Zheng et al. (2023) show different findings from video-based and in-situ studies, Warren-Westgate, Jackson, Blenkinsop, and Hiley (2021) argue that more representative response instructions and experimental designs might allow researchers to retain more control while encouraging responses more typical of those from in-situ studies. Warren-Westgate et al. (2021) used a semi-immersive environment to try to identify the time window in which players become deceived ("deception susceptibility") as opposed to the more commonly examined window in which response accuracy improves rapidly from a low level ("deception detection"). ...
... It may be the case that both deceptive actions and exaggeration act similarly to the loading of a limb to constraint the range of action outcomes earlier in the action. For example, Warren-West and Jackson et al. used signal detection approach to perceiving deception and found that higher skilled sportspeople were less susceptible to deception early in the action sequence (Warren-West & Jackson, 2020; Warren-Westgate, Jackson, Blenkinsop, & Hiley, 2021) potentially because a deceptive action early in the movement may have constrained the outcome. In the past, the relationship between confidence and accuracy has been used to provide evidence on perceptual and cue-based mode of functioning (Runeson, Juslin, & Olsson, 2000) or conscious processes, the role of prior predictions and sensory information in perception (Feldman & Friston, 2010) in anticipation skill. ...
Inertial properties of throwing or striking actions constrain action outcomes, but their role in anticipation skill has not been investigated yet. Therefore, the aim of this study was to systematically investigate the effect of inertial constraints on anticipation skill. Fifteen semi-professional and fifteen novice soccer players were tasked with determining the kick direction of penalty kicks occluded at 160 ms, 80 ms before ball-foot contact, at ball-foot contact, or 80 ms after ball-foot contact. The inertial constraints were manipulated by loading the kicking leg with a 2.25 kg weight around the shank of the kicking leg and were compared with unloaded kicks. Anticipation accuracy of kick direction, response time, and decision confidence were recorded. It was found that loaded kick directions were anticipated more accurately, faster, and at earlier occlusion periods than unloaded kicks. The higher accuracy for the loaded kicks was found in the earlier occlusion conditions in experts compared to novices, as were the positive relationships between accuracy and confidence. It was concluded that the perception of the inertial constraints of the kicking action allowed for earlier anticipation of kick direction. It is proposed that accurate perception of the biomechanical property radius of gyrations in the body segments linking proximal to distal towards the kicking foot may provide this information.
... High-skilled and recreational rugby players were equally vulnerable to deception. However, high-skilled players were faster to discover that the actual situation did not match their expectation, allowing them to respond more effectively to deceptive behavior (Warren-Westgate, Jackson, Blenkinsop, & Hiley, 2021). ...
Prior studies have shown that athletes possess an excellent ability for action anticipation. However, it is not clear how athletes manage to regulate their behaviors when predicted outcomes deviate from actual outcomes. Based on Bayes theory and the predicted response outcome (PRO) model, the current study explored this question using novice and expert table tennis players. Discrepancies between predicted outcomes and actual outcomes were varied into seven conditions. We first examined the differences between experts and novices in a congruence discrimination task and confirmed that experts were better than novices at identifying discrepancies. Subsequently, EEG technology was used to further explore the specific behavior and neural activity in experts during discrepancy processing. Reaction time and theta oscillations gradually increased as the size of discrepancy between the predicted and the actual outcomes increased. These results suggest that experience promotes the monitoring of discrepancies between predicted and actual outcomes in athletes leading to flexibility in coping with varying degrees discrepancy.
Expert sport performers cope with a multitude of visual information to achieve precise skill goals under time stress and pressure. For example, a major league baseball or cricket batter must read opponent variations in actions and ball flight paths to strike the ball in less than a second. Crowded playing schedules and training load restrictions to minimise injury have limited opportunity for field-based practice in sports. As a result, many sports organisations are exploring the use of virtual reality (VR) simulators. Whilst VR synthetic experiences can allow greater control of visual stimuli, immersion to create presence in an environment, and interaction with stimuli, compared to traditional video simulation, the underpinning mechanisms of how experts use visual information for anticipation have not been properly incorporated into its content design. In themes, this opinion article briefly explains the mechanisms underpinning expert visual anticipation, as well as its learning and transfer, with a view that this knowledge can better inform VR simulator content design. In each theme, examples are discussed for improved content design of VR simulators taking into consideration its advantages and limitations relative to video simulation techniques. Whilst sport is used as the exemplar, the points discussed have implications for skill learning in other domains, such as military and law enforcement. It is hoped that our paper will stimulate improved content design of VR simulators for future research and skill enhancement across several domains.
We examined the effectiveness of perceptual training on the performance of handball goalkeepers when anticipating the direction of both direct and deceptive 7-m throws. Skilled goalkeepers were assigned equally to three matched-ability groups based on their pre-test performance: a perceptual training group (n = 14) received video-based perceptual training, a placebo training group (n = 14) received video-based regular training and a control group received no training. Participants in the perceptual training group significantly improved their performance compared to both placebo and control groups; however, anticipation of deceptive throws improved less than for direct throws. The results confirm that although anticipating deception in handball is a challenging task for goalkeepers, task-specific perceptual training can minimise its effect and improve performance.
Cricket umpires are required to make high-pressure, match-changing decisions based on multiple complex information sources under severe temporal constraints. The aim of this study was to examine the decision-making and perceptual-cognitive differences between expert and novice cricket umpires when judging leg before wicket (LBW) decisions. Twelve expert umpires and 19 novice umpires were fitted with an eye-tracker before viewing video-based LBW appeals. Dependent variables were radial error (cm), number of fixations, average fixation duration (ms), final fixation duration (ms), and final fixation location (%). Expert umpires were significantly more accurate at adjudicating on all aspects of the LBW law, compared to the novice umpires (p < .05). The expert umpires’ final fixation prior to ball-pad contact was directed significantly more towards the stumps (p < .05), whereas the novice umpires directed their final fixation significantly more towards a good length (p < .05). These data suggest that expert umpires utilize specialized perceptual-cognitive skills, consisting of a gaze anchor on the stumps in order to overcome the processing demands of the task. These data have implications for the training of current and aspiring umpires in order to enhance the accuracy of LBW decision-making across all levels of the cricketing pyramid.
In three experiments, we investigated the effect of unconscious social priming on human behavior in a choice reaction time task. Photographs of a basketball player passing a ball to the left/right were used as target stimuli. Participants had to respond to the pass direction either by a whole-body (complex) response or a button-press (simple) response. Visually masked stimuli, showing both a task-relevant cue (pass direction) and a task-irrelevant, social cue (gaze direction), were used as primes. Subliminal social priming was found for kinematic (center of pressure) and chronometric measures (response times): gaze direction in the primes affected responses to the pass direction in the targets. The social priming effect diminished when gaze information was unhelpful or even detrimental to the task. Social priming of a complex behavior does not require awareness or intentionality, indicating automatic processing. Nevertheless, it can be controlled by top-down, strategic processes.
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.
Frequently, in rugby, players incorporate deceptive motions (e.g., a side-step) in order to pass their opponent. Previous works showed that expert defenders are more efficient in detecting deceptive motions. Performance was shown to be correlated with the evolution of the center of gravity of the attacker, suggesting that experts may rely on global motion cues. This study aims at investigating whether a representation of center of gravity can be useful for training purposes, by using this representation alone or by combining it with the local motion cues given by body parts. We designed an experiment in virtual reality to control the motion cues available to the defenders. Sixteen healthy participants (seven experts and nine novices) acted as defenders while a virtual attacker approached. Participants completed two separate tasks. The first was a time occlusion perception task, occlusion after 100ms, 200ms or 300ms after the initial change in direction, thereafter participants indicated the passing direction of the attacker. The second was a perception-action task, participants were instructed to intercept the oncoming attacker by displacing medio-laterally. The attacker performed either a non-deceptive motion, directly toward the final passing direction or a deceptive motion, initially toward a false direction before quickly reorienting to the true direction. There was a main effect of expertise, appearance, cut off times and motion on correct responses during both tasks. There was an interaction between visual appearance and expertise, and between motion type and expertise during the perception task, however, this interaction was not present during the perception-action task. We observed that experts maintained superiority in the perception of deceptive motion; however when the visual appearance is reduced to global motion alone the difference between novices and experts is reduced. We further explore the interactions and discuss the effects observed for the visual appearance and expertise.
The ability to differentiate genuine and deceptive actions was examined using a combination of spatial and temporal occlusion to examine sensitivity to lower body, upper body, and full body sources of visual information. High-skilled and low-skilled association football players judged whether a player genuinely intended to take the ball to the participant’s left or right or intended to step over the ball then take it in the other direction. Signal detection analysis was used to calculate measures of sensitivity (d′) in differentiating genuine and deceptive actions and bias (c) toward judging an action to be genuine or deceptive. Analysis revealed that high-skilled players had higher sensitivity than low-skilled players and this was consistent across all spatial occlusion conditions. Low-skilled players were more biased toward judging actions to be genuine. Receiver Operating Characteristic (ROC) curves revealed that accuracy on deceptive trials in the lower body and full body conditions most accurately classified participants as high-skilled or low-skilled. The results highlight the value of using signal detection analysis in studies of deceptive actions. They suggest that information from the lower body or upper body was sufficient for differentiating genuine and deceptive actions and that global information concurrently derived from these sources was not necessary to support the expert advantage.
The ability to visually track, using smooth pursuit eye movements, moving objects is critical in both perceptual and action tasks. Here, by asking participants to view a moving target or track it with their hand, we tested whether different task demands give rise to different gaze strategies. We hypothesized that during hand tracking, in comparison to eye tracking, the frequency of catch-up saccades would be lower, and the smooth pursuit gain would be greater, because it limits the loss of stable retinal and extra-retinal information due to saccades. In our study participants viewed a visual target that followed a smooth but unpredictable trajectory in a horizontal plane and were instructed to either track the target with their gaze or with a cursor controlled by a manipulandum. Although the mean distance between gaze and target was comparable in both tasks, we found, consistent with our hypothesis, an increase in smooth pursuit gain and a decrease in the frequency of catch-up saccades during hand tracking. We suggest that this difference in gaze behavior arises from different tasks demands. Whereas keeping gaze close to the target is important in both tasks, obtaining stable retinal and extra-retinal information is critical for guiding hand movement.
Performing deceptive actions is a wide-spread phenomenon in sports and it is of considerable practical relevance to know whether or not a fake or a disguised action decreases the opponents’ performance. Therefore, research on deceptive actions for various sport disciplines (e.g., cricket, rugby, martial arts, soccer, and basketball) has been conducted. This research is scattered, both across time and scientific disciplines. Here, we aim to systematically review the empirical work on deceptive actions in interactive sports and want to give an overview about several issues investigated in the last decades. Three main topics of the detected literature were discussed here: (1) the role of expertise for the recognition of deceptive actions, (2) the cognitive mechanisms underlying the processing of deceptive actions, and (3) the pros and cons of in situ research designs. None of these themes seems to be settled and therefore, they should be considered in future research agendas.
It is widely accepted that the sources of information used to guide interceptive actions depend on conflicting spatiotemporal task demands. However, there is a paucity of evidence that shows how information pick-up during interceptive actions is adapted to such conflicting constraints. The present study therefore examined the effects of systematic manipulations of spatiotemporal constraints on performance, timing and gaze in an in situ interceptive action. To this end, expert futsal goalkeepers faced penalty kicks taken from 10 m and 6 m. With the more lenient spatiotemporal constraints (i.e., kicks from 10 m), the goalkeepers saved more kicks, initiated their actions later, and looked longer toward ball relative to the penalty takers’ body. Furthermore, analysis of gaze patterns showed that interindividual variations in information pick-up were related to the unfolding of the penalty taker’s action, revealing a less variable, funnel-like gaze pattern toward the end of the action. These findings are interpreted to reflect that changes in spatiotemporal demands induce the differential use of information for the accurate control of interceptive actions.
The ability of the attacking team to break through the defensive line is a key indicator of success as it creates opportunities to score tries. The aim of this study was to analyse line breaks and identify the associated skills and playing characteristics. The 2013 Super Rugby season (125 games) was analysed, in which 362 line breaks were identified and coded using variables that assessed team patterns and non-contact attacking skills in the phases preceding the line break. There was an average of 3 line breaks per game, with 39% of line breaks resulting in a try. Line breaks occurred when the ball-carrier was running fast [61%, x 2 (4) = 25.784, p = 0.000, Cramer's v = 0.1922, weak]. At a moderate distance, short lateral passes (19%) and skip passes (15%) attributed to the highest percentage of line breaks [x 2 (26) = 50.899, p = 0.036, Cramer's v = 0.2484, moderate]. Faster defensive line speeds resulted in more line breaks [x 2 (12) = 61.703, p < 0.001, Cramer's v = 0.3026, moderate]. Line breaks are associated with overall team success and try scoring opportunities. Awareness of the defenders line speed and depth, fast running speed when receiving the ball and quick passing between attackers to the outside backs creates line break opportunities. During training, coaches should emphasise the movement speed of the ball between attackers and manipulate the speed and distance of the defenders.
The purpose of the current article is to review findings from the visual anticipation literature with a particular focus on penalty kick goalkeeping in Association football. We give a brief introduction to the area of research before providing reviews of two recent studies. First, we focus on the applied implications of a study that examined the effect of deception and non-deception penalty kick strategies on goalkeeping performance. Second, we consider further limiting factors on the accuracy of goalkeeper visual anticipation through examination of the relationship between goalkeeper action capabilities and the timing and accuracy of goalkeeper responses. Finally, the implications of the results are considered with recommendations for coaching practices aimed at improving visual anticipation skills.
We investigated the anticipatory skill of rugby league players using a video-based test that encompassed game-specific scenarios (and more than one attacking player). Rugby league players from one of three different skill levels (high-skilled, intermediate-skilled, and low-skilled), and drawn from three different age levels (senior, under 20, and under 16 years) participated in this study. Video images of various rugby league-specific scenarios, presented from the perspective of a particular player, were projected on to a wall. Players were instructed to react to these plays as they would in a game situation. The test was performed under single-task (i.e., anticipation test in isolation) and dual-task (i.e., the anticipation test while also performing a secondary verbal tone recognition task) conditions. No significant dual-task decrements were observed for primary task performance in any of the playing levels or age groups. However, reductions in performance on the secondary tone recognition task were evident in the form of decreased tone response accuracy and increased verbal response times. Greater response accuracy and faster response times were observed with increases in age and playing level, highlighting the centrality of anticipation to skilled performance in rugby league. The differences in anticipatory skill between playing levels and age groups suggest that the accumulation of a high volume of sport-specific experience may facilitate the development of perceptual expertise in rugby league players. (PsycINFO Database Record (c) 2013 APA, all rights reserved)
Expert soccer players are able to utilize their opponents' early body kinematics to predict the direction in which the opponent will move. We have previously demonstrated enhanced fMRI activation in experts in the motor components of an action observation network (AON) during sports anticipation tasks. Soccer players often need to prevent opponents from successfully predicting their line of attack, and consequently may try to deceive them; for example, by performing a step-over. We examined how AON activations and expertise effects are modified by the presence of deception. Three groups of participants; higher-skilled males, lower-skilled males, and lower-skilled females, viewed video clips in point-light format, from a defender's perspective, of a player approaching and turning with the ball. The observer's task in the scanner was to determine whether the move was normal or deceptive (involving a step-over), while whole-brain functional images were acquired. In a second counterbalanced block with identical stimuli the task was to predict the direction of the ball. Activations of AON for identification of deception overlapped with activations from the direction identification task. Higher-skilled players showed significantly greater activation than lower-skilled players in a subset of AON areas; and lower-skilled males in turn showed greater activation than lower-skilled females, but females showed more activation in visual cortex. Activation was greater for deception identification than for direction identification in dorsolateral prefrontal cortex, medial frontal cortex, anterior insula, cingulate gyrus, and premotor cortex. Conversely, greater activation for direction than deception identification was found in anterior cingulate cortex and caudate nucleus. Results are consistent with the view that explicit identification of deceptive moves entails cognitive effort and also activates limbic structures associated with social cognition and affective responses.
Fast motor reactions in sports often require the ability to predict the intended action of an opponent as early as possible. Therefore, the present paper investigates whether beach volleyball athletes are able to recognize different attack hits (i.e. smash vs. poke shot) at an earlier stage of the movement than novices. Beach volleyball athletes and novices took part in a response priming experiment (Experiment 1). Participants had to decide whether a presented target picture depicts a smash or a poke shot. Importantly, the preceding prime pictures were taken from different stages of the movements varying between the jump (beginning of the movements) and the hand-ball contact (end of the movements). Diverging response congruency effects was found for athletes and novices. Athletes were able to recognize at an earlier movement stage than novices which kind of attack hit was shown at the prime picture. It is suggested that athletes might implicitly read movement-related patterns in the depicted athlete's body posture (e.g. the angle of the elbow). In contrast, novices might use information which is easier to access (e.g. hand-ball relation). In a second experiment, novice participants received a visual training to test for a potential perceptual source of the priming effects. Notably, participants did not improve their ability to differentiate the volleyball techniques, indicating that a better recognition performance in athletes is based on motor and not on perceptual expertise.
Estimatingd′ from extreme false-alarm or hit proportions (p = 0 orp = 1) requires the use of a correction, because thez score of such proportions takes on infinite values. Two commonly used corrections are compared by using Monte-Carlo simulations.
The first is the 1/(2N) rule for which an extreme proportion is corrected by this factor befored′ is calculated. The second is the log-linear rule for which each cell frequency in the contingency table is increased by
0.5 irrespective of the contents of each cell. Results showed that the log-linear rule resulted in less biased estimates ofd′ that always underestimated populationd′. The 1/(2N) rule, apart from being more biased, could either over- or underestimate populationd′.
Expertise in sports enhances the ability to anticipate forthcoming events from the observation of a player's actions. In the present study, we investigated whether this ability is applicable to deceptive action. In three experiments, performance at anticipating the direction change of a running opponent was examined with experienced rugby players and novice counterparts. These experiments were conducted with reaction-time and temporal-occlusion tasks, in combination with eye movement recordings and the presentation of filmed actions and their point-light representations. The main finding was that the experienced players were superior to the novices in their anticipation of deceptive actions, although their performance was still impaired by the deception, in comparison with their anticipation of nondeceptive actions. We also found that the experienced players anticipated nondeceptive actions less accurately than the novices, suggesting that the players' expectations of deceptive actions worked negatively on their judgments of nondeceptive actions. The results obtained with the point-light representations closely resembled those obtained with the filmed sequences, indicating that anticipation was based on the kinematics of the running action. These results are discussed in the context of recent developments in research on expertise and deception in sports.
Abstract We quantify the nature and frequency of anticipation behaviours in professional tennis using video coding of incidents where the time delay between the opponent's stroke and the reaction of the player were recorded. We argue that anticipation is based on uncertain information and should lead in some situations to erroneous decisions. We identified the transition between reaction (with 100% accuracy in the selection of where the ball is played on the court) and anticipation (with less than 100% accuracy) as being 140-160 ms after ball contact. Anticipation behaviours occurred on between 6.14% and 13.42% of the coded situations. These anticipation behaviours appeared almost exclusively in 'unfavourable' situations, where the opponent had a significant tactical advantage, with the type of playing surface having only a limited effect. Moreover, the decrease in accuracy with shorter response times is not monotonic, with an increase in response accuracy being observed for times shorter than 120 ms before ball contact. We propose that very early anticipation behaviours occur when players use significant context-specific information before the opponent's stroke. When such information is not available, players produce anticipation behaviours that are closer to the moment of ball-racket contact using information that is more likely to be based on the opponent's preparation of the stroke. This study opens new directions for research focusing on the testing and training of anticipation in fast ball sports.
Human movement containing deception about the true outcome is thought to be perceived differently compared to the non-deceptive version. Exaggeration in the movement is thought to change the perceiver's mode of functioning from an invariant to a cue-based mode. We tested these ideas by examining anticipation in skilled and less skilled soccer players while they viewed temporally occluded (-240 ms, -160 ms, -80 ms, 0 ms, +80 ms) deceptive, non-deceptive, and non-deceptive-exaggerated penalty kicks. Kinematic analyses were used to ascertain that the kicking actions differed across conditions. The accuracy of judging the direction of an opponent's kick as well as response confidence were recorded. Players were over confident when anticipating deceptive penalty kicks compared to non-deceptive kicks, suggesting a cue-based mode was used. Furthermore, there was a significant relationship between less skilled players' confidence ratings and their accuracy 80 ms before ball-foot contact in the deceptive and non-deceptive-exaggerated conditions, but not the non-deceptive condition. Because both deceptive and non-deceptive-exaggerated kicks contained exaggeration, results suggest exaggerated movements in the kickers' action at 80 ms before ball-foot contact explains why a cue-based mode prevails when anticipating deceptive kicks at this time point.
Although coordinated patterns of body movement can be used to communicate action intention, they can also be used to deceive. Often known as deceptive movements, these unpredictable patterns of body movement can give a competitive advantage to an attacker when trying to outwit a defender. In this particular study, we immersed novice and expert rugby players in an interactive virtual rugby environment to understand how the dynamics of deceptive body movement influence a defending player's decisions about how and when to act. When asked to judge final running direction, expert players who were found to tune into prospective tau-based information specified in the dynamics of 'honest' movement signals (Centre of Mass), performed significantly better than novices who tuned into the dynamics of 'deceptive' movement signals (upper trunk yaw and out-foot placement) (p<.001). These findings were further corroborated in a second experiment where players were able to move as if to intercept or 'tackle' the virtual attacker. An analysis of action responses showed that experts waited significantly longer before initiating movement (p<.001). By waiting longer and picking up more information that would inform about future running direction these experts made significantly fewer errors (p<.05). In this paper we not only present a mathematical model that describes how deception in body-based movement is detected, but we also show how perceptual expertise is manifested in action expertise. We conclude that being able to tune into the 'honest' information specifying true running action intention gives a strong competitive advantage.
People can often anticipate the outcome of another person's actions based on visual information available in the movements of the other person's body. We investigated this problem by studying how goalkeepers anticipate the direction of a penalty kick in soccer. The specific aim was to determine whether the information used to anticipate kick direction is best characterized as local to a particular body segment or distributed across multiple segments. In Experiment 1, we recorded the movements of soccer players as they kicked balls into a net. Using a novel method for analyzing motion capture data, we identified sources of local and distributed information that were reliable indicators of kick direction. In Experiments 2 and 3, subjects were presented with animations of kickers' movements prior to foot-to-ball contact and instructed to judge kick direction. Judgments were consistent with the use of distributed information, with a possible small contribution of local information.
Misdirection refers to the magician’s ability to manipulate people’s attention, thoughts, and memory. It has been argued that some of the techniques used by magicians to orchestrate people’s attention and awareness may provide valuable insights into human cognition. In this paper we review the scientific, as well as some of the magic literature on misdirection. We focus on four main points: (1) the magician’s concept of misdirection, (2) the paradigms used to study misdirection scientifically, (3) review of the current scientific findings, and (4) future directions.
In many competitive sports, players try to deceive their opponents about their behavioral intentions by using specific body movements or postures called fakes. For example, fakes are performed in basketball when a player gazes in one direction but passes or shoots the ball in another direction to avert efficient defense actions. The present study aimed to identify the cognitive processes that underlie the effects of fakes. The paradigmatic situation studied was the head fake in basketball. Observers (basketball novices) had to decide as quickly as possible whether a basketball player would pass a ball to the left or to the right. The player's head and gaze were oriented in the direction of an intended pass or in the opposite direction (i.e., a head fake). Responding was delayed for incongruent compared to congruent directions of the player's gaze and the pass. This head fake effect was independent of response speed, the presence of a fake in the immediately preceding trial, and practice with the task. Five further experiments using additive-factors logic and locus-of-slack logic revealed a perceptual rather than motor-related origin of this effect: Turning the head in a direction opposite the pass direction appears to hamper the perceptual encoding of pass direction, although it does not induce a tendency to move in the direction of the head's orientation. The implications of these results for research on deception in sports and their relevance for sports practice are discussed.
Skilled performers interpret cues in the preparatory movements of their opponents to anticipate future events in many sports. Little work has tested whether these cues can be disguised. Using a temporal occlusion paradigm, this paper examines the effect of disguise on an Australian sample of expert (16 male, 2 female, age M = 24.67, SD = 9.47 years) and novice players' (24 male, 38 female, age M = 22.26, SD = 5.24 years) anticipation of tennis ground strokes. Analysis of variance (ANOVA) showed that expert anticipation was more accurate than novice overall (p < .001), and disguise reduced accuracy (p = .001). The disguise effect differed by expertise across occlusion points (p = .027). The experts' anticipatory advantage was removed by disguise at 40 ms before contact. Novice performance was significantly below chance for disguise shots occluded at contact. These results indicate that disguise is an important topic for research and practice.
We designed a magic trick that could be used to investigate how misdirection can prevent people from perceiving a visually salient event, thus offering a novel paradigm to examine inattentional blindness. We demonstrate that participants' verbal reports reflect what they saw rather than inferences about how they thought the trick was done and thus provide a reliable index of conscious perception. Eye movements revealed that for a subset of participants their conscious perception was not related to where they were looking at the time of the event and thus demonstrate how overt and covert attention can be spatially dissociated. However, detection of the event resulted in rapid shifts of eye movements towards the detected event, thus indicating a strong temporal link between overt and covert attention, and that covert attention can be allocated at least 2 or 3 saccade targets ahead of where people are fixating.
The authors examined the importance of local dynamical information when anticipating tennis shot direction. In separate experiments, they occluded the arm and racket, shoulders, hips, trunk, and legs and locally neutralized dynamical differences between shot directions, respectively. The authors examined the impact of these manipulations on resulting (display) dynamics and the ability of participants with varying perceptual skills to anticipate shot direction. The occlusion manipulation affected the display dynamics to a larger extent than did the neutralization manipulation. Although the authors observed a decrement in performance when local information from the arm and racket was occluded or neutralized and when information from the trunk and legs was neutralized, the results generally suggest that participants anticipated shot direction through a more global perceptual approach, particularly in perceptually skilled participants.
What information underwrites visual anticipation skill in dynamic sport situations? We examined this question on the premise that the optical information used for anticipation resides in the dynamic motion structures, or modes, that are inherent in the observed kinematic patterns. In Experiment 1, we analyzed whole-body movements involved in tennis shots to different directions and distances by means of principal component analysis. The shots differed in the few modes that captured most of the variance, especially as a function of shot direction. In Experiments 2 and 3, skilled and less skilled tennis players were asked to anticipate the direction of simulated shots on the basis of kinematic patterns in which only the constituent dynamic structures were manipulated. The results indicated that players predicted shot direction by picking up the information contained in multiple low-dimensional dynamic modes, suggesting that anticipation skill in tennis entails the extraction of this dynamic information from high-dimensional displays.
The benefits and costs of prior expectations that are (i.e., congruent) or are not in harmony (i.e., incongruent) with action outcomes appear to be balanced; however, researchers have yet to examine the influence on skilled detection of deception. In this study we investigated whether response bias resulting from probability information (a) is stronger for low-skilled than high-skilled participants, (b) is stronger for deceptive actions than genuine actions, and (c) impairs the discriminability of genuine and deceptive actions. High-skilled (n = 15) and low-skilled (n = 15) soccer players responded to life-sized projected video clips showing an oncoming opponent taking the ball to their left or right, with or without a deceptive ‘stepover’ action. Three probability conditions were used with respect to outcome direction: 50/50, 67/33, and 83/17. Participants responded by stepping on one of two corresponding pressure mats, as if attempting to intercept the player. Response accuracy for genuine and deceptive actions was used to generate measures of bias (c) and sensitivity (d’). The results confirmed stronger probability bias for deceptive actions than genuine ones, and for low-skilled than high-skilled participants. Congruence between high outcome probability and the direction of the fake significantly enhanced the effectiveness of the deceptive action. The study provides the first evidence that outcome probability information impairs skilled detection of deceptive intent.
Objectives
The current study sought to examine the relative contributions of kinematic and situational probability information to anticipation using different levels of disguised kinematics. More specifically, it was tested whether the weighting of the informational sources (kinematic vs. probabilistic) shifts relative to the certainty of the available kinematic information.
Design and Method
Human-like avatars were generated performing penalty throws and displayed in a virtual reality environment. The ambiguity of the kinematic information available from the avatars was systematically manipulated using linear morphing between genuine and disguised throws. In a perceptual classification task, trained novice observers (N = 23) were asked to classify as quickly and accurately as possible whether observed throws were either genuine or disguised. In addition, information about the performer’s action preferences was also systematically manipulated by explicitly informing participants about the performer’s AP to disguise their throw (25%, 50%, and 75%).
Results
Participants’ response behavior showed that observers relied more heavily on the probabilistic information when the kinematics were ambiguous. For the AP 25% condition, observers were more likely to report that ambiguous throws were genuine (p < 0.001), whereas they classified the ambiguous throws as being disguised in the AP 75% condition (p < 0.001).
Conclusion
Findings suggest that observers rely more strongly on non-kinematic (situational probability) information when the reliability of the observable movement kinematics becomes less certain.
The History and Scope of Cognitive Sport PsychologyEffects of Cognitive Factors on Sports PerformanceEffects of Sports Participation on CognitionSummary, Conclusions, and Future DirectionsReferences
Task influence has long been known to play a major role in the way our eyes scan a scene. Yet most studies focus either on visual search or on a sequence of active tasks in complex real world scenarios. Few studies have contrasted the distribution of eye fixations during viewing and grasping objects. Here we address how attention is deployed when different actions have to be planned on objects, in contrast to when the same objects have to be categorized. In this respect, we are particularly interested in the role every fixation plays in the unfolding dynamics of action control. To investigate these issues, we conducted an eye-tracking experiment in which participants were shown images of real-world objects. Subjects were either to assign the displayed objects to one of two classes (categorization task), to mimic lifting (lifting task), or to mimic opening the object (opening task). Results suggest that even on simplified, two dimensional displays the eyes reveal the intentions of the participant in an anticipatory fashion. In the case of active tasks, already the second saccade after the stimulus onset was directed towards the central region between the two locations where the thumb and the rest of the fingers would be placed. An analysis of saliency at fixation locations showed that fixations in active tasks have a higher correspondence with salient features than fixations in the passive tasks. We suggest that attention flexibly coordinates visual selection for information retrieval and motor planning and hence works as a gateway between three components, linking the task (action), the object (target), and the effector (hand) in an effective way.
Purpose:
We examined links between the kinematics of an opponent's actions and the visual search behaviors of badminton players responding to those actions.
Method:
A kinematic analysis of international standard badminton players (n = 4) was undertaken as they completed a range of serves. Video of these players serving was used to create a life-size temporal occlusion test to measure anticipation responses. Expert (n = 8) and novice (n = 8) badminton players anticipated serve location while wearing an eye movement registration system.
Results:
During the execution phase of the opponent's movement, the kinematic analysis showed between-shot differences in distance traveled and peak acceleration at the shoulder, elbow, wrist and racket. Experts were more accurate at responding to the serves compared to novice players. Expert players fixated on the kinematic locations that were most discriminating between serve types more frequently and for a longer duration compared to novice players. Moreover, players were generally more accurate at responding to serves when they fixated vision upon the discriminating arm and racket kinematics.
Conclusions:
Findings extend previous literature by providing empirical evidence that expert athletes' visual search behaviors and anticipatory responses are inextricably linked to the opponent action being observed.
This study addresses the utility of the kinematics of penalty takers for goalkeepers in association football. Twelve professional and semi-professional players shot to one side of the goal with (deceptive condition) or without (non-deceptive condition) simulating a shot to the opposite side. The body kinematics of the penalty takers were registered with motion-capture apparatus. Correlation and regression techniques were used to determine the relation between the shot direction and aspects of the penalty taker’s kinematics at different moments. Several kinematic variables were strongly correlated with shot direction, especially those related to the lower part of the body. Some of these variables, including the angle of the non-kicking foot, acquired high correlations at time intervals that are useful to goalkeepers. Compound variables, here defined as linear combinations of variables, were found to be more useful than locally defined variables. Whereas some kinematic variables showed substantial differences in their relation to ball direction depending on deception, other kinematic variables were less affected by deception. Results are interpreted with the hypothesis of non-substitutability of genuine action. The study can also be interpreted as extending the correlation and regression methodology, often used to analyze variables defined at single moments, to the analysis of variables in a time continuous fashion.
Objectives: Visual identification and anticipation of an opponent’s action intentions is crucial for successful performance in interactive situations such as team-handball penalties. We conducted two experiments to examine experienced and novice team-handball goalkeepers’ ability to predict the type of throw in handball penalties and to identify the observers’ reliance on local versus globally distributed spatial cues.
Design and methods: In Experiment 1, following a 2 (Skill) x 5 (Temporal Occlusion Condition) factorial design participants were provided with videos of team-handball penalties where the amount of viewing time was varied. In Experiment 2, another sample of experienced and novice goalkeepers watched videos of spatially manipulated penalties where specific parts of the thrower’s body or the ball were either removed or presented in isolation (2 [Skill] x 9 [Display Condition] factorial design).
Results: In Experiment 1, experienced goalkeepers outperformed novices and both groups similarly improved their performances with later occlusion conditions. In Experiment 2, experienced goalkeepers were again superior to novices, and local cues (e.g., ball and hand) were sufficient for better than chance predictions in both groups. Moreover, experienced in contrast to novice goalkeepers (i) suffered from the removal of and (ii) benefited from the addition of distal (i.e., throwing arm and ball) as well as proximal (i.e., upper body) kinematic features.
Conclusions: Our research is in line with previous findings on perceptual-cognitive expertise in sports and suggests that experienced team-handball goalkeepers rely on multiple, globally distributed cues when making anticipatory judgments.
G*Power (Erdfelder, Faul, & Buchner, 1996) was designed as a general stand-alone power analysis program for statistical tests commonly used in social and behavioral research. G*Power 3 is a major extension of, and improvement over, the previous versions. It runs on widely used computer platforms (i.e., Windows XP, Windows Vista, and Mac OS X 10.4) and covers many different statistical tests of the t, F, and chi2 test families. In addition, it includes power analyses for z tests and some exact tests. G*Power 3 provides improved effect size calculators and graphic options, supports both distribution-based and design-based input modes, and offers all types of power analyses in which users might be interested. Like its predecessors, G*Power 3 is free.
The importance of perceptual-cognitive expertise in sport has been repeatedly demonstrated. In this study we examined the role of different sources of visual information (i.e., foveal versus peripheral) in anticipating volleyball attack positions. Expert (n = 11), advanced (n = 13) and novice (n = 16) players completed an anticipation task that involved predicting the location of volleyball attacks. Video clips of volleyball attacks (n = 72) were spatially and temporally occluded to provide varying amounts of information to the participant. In addition, participants viewed the attacks under three visual conditions: full vision, foveal vision only, and peripheral vision only. Analysis of variance revealed significant between group differences in prediction accuracy with higher skilled players performing better than lower skilled players. Additionally, we found significant differences between temporal and spatial occlusion conditions. Both of those factors interacted separately, but not combined with expertise. Importantly, for experts the sum of both fields of vision was superior to either source in isolation. Our results suggest different sources of visual information work collectively to facilitate expert anticipation in time-constrained sports and reinforce the complexity of expert perception.
Athletes exhibit better anticipation abilities than novices. However, it is not known whether this difference is related to different visual perceptions between them and which neural elements are involved in producing this difference. Fifteen elite basketball players and fifteen novices participated in an action anticipation task with basketball free throw. Accurate rate for anticipation and gaze behavior were analyzed. Functional brain activity was recorded using functional magnetic resonance imaging. We found that the accurate rate for anticipation was higher in athletes than that in novices. Athletes showed more stable gaze fixation than novices and the locus of fixation was reliable in athletes but not in novices. Athletes showed higher activity in inferior parietal lobule and inferior frontal gyrus than novices during action anticipation. We conclude that the processes for action anticipation in elite athletes and novices are different and this difference is caused by different visual perceptions between them.
Evasive change-of-direction manoeuvres (agility skills) are a fundamental ability in rugby union. In this study, we explored the attributes of agility skill execution as they relate to effective attacking strategies in rugby union. Seven Super 14 games were coded using variables that assessed team patterns and individual movement characteristics during attacking ball carries. The results indicated that tackle-breaks are a key determinant of try-scoring ability and team success in rugby union. The ability of the attacking ball carrier to receive the ball at high speed with at least two body lengths from the defence line against an isolated defender promoted tackle-breaks. Furthermore, the execution of a side-step evasive manoeuvre at a change of direction angle of 20-60o and a distance of one to two body lengths from the defence, and then straightening the running line following the initial direction change at an angle of 20-60o, was associated with tackle-breaks. This study provides critical insight regarding the attributes of agility skill execution that are associated with effective ball carries in rugby union.
The theory of affordances, a conceptual pillar of the ecological approach to perception and action, has the potential to become a guiding principle for research on perception and action in sport. Affordances are opportunities for action. They describe the environment in terms of behaviors that are possible at a given moment under a given set of conditions. Affordances capture the tight coupling between per-ception and action, and allow for the prospective and moment-to-moment control of activity that is characteristic of fluent, fast-paced behavior on the playing field. We begin with an overview of the ecological approach and the principle of direct perception, using past research on interceptive action to illustrate how this princi-ple has been put to work to capture information-movement relations in perceptual-motor skill. We then review theory and research on body-scaled, action-scaled, and social affordances, highlighting outstanding questions that provide opportunities for new research on affordances in the context of sport. We conclude with consider-ation of affordances as providing a functional semantics for sports.
Two experiments are described comparing the temporal and spatial characteristics of the anticipatory cues used by expert ( n =20) and novice ( n =35) racquet sport players. In both experiments the perceptual display available in badminton was simulated using film, and display characteristics were selectively manipulated either by varying the duration of the stroke sequence that was visible (Experiment 1) or by selectively masking specific display features (Experiment 2). The subjects* task in all cases was to predict the landing position of the stroke they were viewing. It was found in Experiment 1 that experts were able to pick up more relevant information from earlier display cues than could novices, and this appeared in Experiment 2 to be due to their ability to extract advance information from the playing side arm, in addition to the racquet itself. These differences, it was concluded, were congruent with predictions that could be derived from traditional information-processing notions related to recognition of display redundancy. The roles of different anticipatory cue sources in the independent predictions of stroke speed and direction were also examined, and it was concluded that directional judgments were more dependent on cue specificity than were depth judgments.
Two not mutually exclusive explanations, perceptual and motor expertise, account for the finding that experts outperform novices in recognizing deceptive actions from bodily (kinematic) cues. The aim of the present study was twofold: First, we sought to examine the impact of motor and perceptual expertise on distinguishing deceptive and non-deceptive actions. Second, we tested the hypothesis that differences in perceptual judgments on deceptive movements vs. non-deceptive movements do not necessarily need to be caused by either perceptual or motor expertise differences, but can also be a result of response bias. Skilled handball players (field players and goalkeepers) and novices had to detect whether a penalty-taker shot or faked a shot at the goal. Signal detection theory (SDT) analysis revealed that skilled handball players outperformed novices in discriminating shots from fakes. No differences in perceptual sensitivity were found between the goalkeepers and the field players. However, SDT analysis showed that goalkeepers were significantly biased to judge movements as deceptive, while neither field players nor novices showed this response bias.
The relationship between perception-action coupling and anticipatory skill in an interceptive task was examined using an in-situ temporal occlusion paradigm. Skilled and novice cricket batsmen were required to predict the direction of balls bowled towards them under four counterbalanced response conditions of increasing perception-action coupling: (i) verbal, (ii) lower-body movement only, (iii) full-body movement (no bat), and (iv) full-body movement with bat (i.e., the usual batting response). Skilled but not novice anticipation was found to improve as a function of coupling when responses were based on either no ball-flight, or early ball-flight information, with a response requiring even the lowest degree of body movement found to enhance anticipation when compared to a verbal prediction. Most importantly, a full-body movement using a bat elicited greater anticipation than an equivalent movement with no bat. This result highlights the important role that the requirement and/or opportunity to make bat-ball interception may play in eliciting skill differences for anticipation. Results verify the importance of using experimental conditions and task demands that closely reflect the natural performance environment in order to reveal the full nature of the expert advantage.
Suddenly changing direction requires a whole body reorientation strategy. In sporting duels such as an attacker vs. a defender in rugby, successful body orientation/reorientation strategies are essential for successful performance. The aim of this study is to examine which biomechanical factors, while taking into account biomechanical constraints, are used by an attacker in a 1 vs. 1 duel in rugby. More specifically we wanted to examine how an attacker tries to deceive the defender yet disguise his intentions by comparing effective deceptive movements (DM(+)), ineffective deceptive movements (DM(-)), and non-deceptive movements (NDM). Eight French amateur expert rugby union players were asked to perform DMs and NDMs in a real 1 vs. 1 duel. For each type of movement (DM(+), DM(-), NDM) different relevant orientation/reorientation parameters, medio-lateral displacement of the center of mass (COM), foot, head, upper trunk, and lower trunk yaw; and upper trunk roll were analyzed and compared. Results showed that COM displacement and lower trunk yaw were minimized during DMs while foot displacement along with head and upper trunk yaw were exaggerated during DMs (DM(+) and DM(-)). This would suggest that the player is using exaggerated body-related information to consciously deceive the defender into thinking he will run in a given direction while minimizing other postural control parameters to disguise a sudden change in posture necessary to modify final running direction. Further analysis of the efficacy of deceptive movements showed how the disguise and deceit strategies needed to be carefully balanced to successfully fool the defender.
Studies of deception detection traditionally have focused on verbal communication. Nevertheless, people commonly deceive others through nonverbal cues. Previous research has shown that intentions can be inferred from the ways in which people move their bodies. Furthermore, motor expertise within a given domain has been shown to increase visual sensitivity to other people's movements within that domain. Does expertise also enhance deception detection from bodily movement? In two psychophysical studies, experienced basketball players and novices attempted to distinguish deceptive intentions (fake passes) and veridical intentions (true passes) from an observed individual's actions. Whereas experts and novices performed similarly with postural cues, only experts could detect deception from kinematics alone. These results demonstrate a link between action expertise and the detection of nonverbal deception.
We examined the mechanisms underpinning anticipation of ground strokes in tennis by perturbing the dynamical information presented at different body regions (+ racket). We interchanged the dynamics at selected regions with those from strokes played to the opposite side of the court. Skilled and less skilled tennis players were required to anticipate stroke direction when presented with filmed sequences in stick figure format. There was a significant Skill x Condition interaction. Skilled players reported lower accuracy scores when both proximal (i.e., shoulders, hips, and legs) and distal (i.e., arm + racket) cues were interchanged, whereas the less skilled players showed a significant decrement only in the arm+racket condition. Findings suggest that skilled players rely on a more 'global' than 'local' perceptual strategy. The greatest decrement in performance and lowest response accuracy scores were reported in the arm + racket condition, highlighting the importance of end-effector information when anticipating opponents' intentions.
The time of occurrence and spatial location of the advance cues used to anticipate the direction and force of an opponent's stroke in squash were examined using a film task. This task, designed to stimulate the normal perceptual display of the defensive player, consisted of two discrete parts, each containing 160 individual stroke sequences (trials). In the first part of the film task, the display was occluded at different time intervals throughout the development of the opponent's stroke and the 16 expert and 20 novice subjects had to predict both the direction (down-wall or cross-court) and force (drive or drop shot) of the opponent's stroke. In the second part of the film task, visibility to selected advance cues was occluded by placing opaque mats on the film surface. Across all of the film task conditions experts were superior to novices in predicting the event outcome from the information available, highlighting the important contribution anticipatory skills make to expert performance in this sport. Analysis of lateral (direction) error showed that the most critical time periods for extracting information about stroke direction are the periods between 160-80 ms prior to racket-ball contact and the period of extended ball flight arising at least 80 ms after contact. Whereas both groups were attuned to this ball flight information, only the experts were capable of picking up information from the early part of the opponent's actions. This early information appeared to be provided by the opposing player's arm action. Similar time periods were found to be also important for the prediction of stroke depth, but in this case both experts and novices were similar in their cue dependence.
Patterns of ocular fixation in free-viewing tasks reflect aspects of visual attention and cognition. To quantify these patterns, fixations must be identified in raw eye movement data by applying explicit spatial and temporal thresholds. A temporal threshold of 200 ms is commonly used in clinical visuocognitive research, despite having been originally derived from a study of eye movements in reading. We systematically explored temporal fixation thresholds below 200 ms, using biologically relevant (human face) and abstract (complex geometric) stimuli. Short fixations (<200 ms) significantly altered spatiotemporal patterns of fixation for both the face and geometric stimuli, by increasing the number of fixations and the scanpath length. A threshold of 100 ms was found to discriminate fixations from other oculomotor activity effectively, and was consistent with current physiological and visuocognitive models. Statistical examination of fixation duration data for each subject suggested the median was a less biased and more robust measure of central tendency than the mean.