How to Trick Your Opponent: A Review Article on Deceptive Actions in Interactive Sports

The kinematics of false intent Conveyed by deceptive sidestep actions

Researchers have identified kinematic differences between deceptive and non-deceptive rugby reorientation actions. However, the honest and deceptive signals corresponded to 'deception detection' (accuracy increasing) rather than signals that caused deception (accuracy decreasing). In this study, statistical parametric mapping and multilevel modelling were applied to examine the kinematic differences between sidestep and non-deceptive actions during the time window of deception. The analysis compared three-dimensional motion capture data from 144 deceptive actions and 144 genuine actions performed by six high-skilled rugby players. Results indicated that the kinematics of deceptive actions were characterized by a combination of exaggerated head roll, outside foot and centre-of-mass displacement, and attenuated thorax roll and yaw relative to genuine actions. These are candidate sources for the cause of deception, either individually or in combination with other sources. Furthermore, the results indicate that previously identified 'honest' signals may not be reliable sources of information earlier in the action sequence.

Action inhibition in a sport-specific paradigm: examining the limits of action control in basketball

To investigate the point where inappropriate defensive movements can no longer be inhibited and to validate suitable stimulus material for constructing a basketball-specific anticipation-response-inhibition task, two experiments were conducted. In Experiment 1, participants without basketball expertise (N = 25) watched a video of a basketball jump shot and were asked to release the space bar at the point when the ball leaves the player's fingertips (go-trials). In 25% of all trials, the video was stopped prematurely and participants should withhold their finger-lift response (stop-trials). A staircase-tracking algorithm was used to adjust the point-in-time when the jump shot was stopped in a way that participants' inhibition rate was at 50% (reflecting the so called "point-of-no-return", PNR). In Experiment 2, the stimulus material was adapted so that stop-trials simulated a pump fake. The PNR in Experiment 1 was located 187 ms and in Experiment 2 177 ms before the point of ball release. Precision performance benefit from practice across blocks and participants delayed their responses after stop-trials in a subsequent go-trial, which reflects strategic post-stop-trial adjustments. Based on the comparable results of previous studies, the given stimulus material is suitable for investigating response inhibition skills in dynamic sport-specific environments.

Expertise and Deceptive Movements in Sport

BACKGROUND

Deceptive movements occur when an actor seeks to fake, hide or delay kinematic information about their true movement outcomes. The purpose of deceptive movements is to impair the perception of opponents (the 'observer') to gain an advantage over them. We argue though that a lack of conceptual clarity has led to confusion about what deception is and in understanding the different approaches by which an actor can deceive their opponent. The aim of this article is to outline a conceptual framework for understanding deceptive movements in sport.

MAIN BODY

Adopting Interpersonal Deception Theory from the field of communication, we define deception as when an actor deliberately alters their actions in an attempt to impair the ability of an observer to anticipate their true action outcomes. Further, deception can be achieved either by what we define as deceit, the act of providing false information, or disguise, the act of concealing the action outcome. Skilled athletes often have actions that are difficult to anticipate, but an action is only classified as containing deception if the actor has explicit intent to deceive an observer. Having outlined the conceptual framework, we then review existing empirical findings on the skilled perception of deceptive movements considering the framework. This approach includes a critical evaluation of the mechanisms known to facilitate the perceptual ability to prevent being deceived, including a consideration of visual search strategies, confidence, the contribution of visual and motor experiences, and the influence of response biases and action capabilities on perceptual performance.

CONCLUSION

The distinction between deceit and disguise particularly helps to show that most research has examined deceit, with little known about how an actor can more effectively disguise their action, or about how an observer can improve their ability to anticipate the outcome of disguised actions. The insights help to identify fruitful areas for future research and outline implications for skill acquisition and performance enhancement.

Neurocognitive Errors and Noncontact Anterior Cruciate Ligament Injuries in Professional Male Soccer Players

CONTEXT

Evidence is emerging that core neurocognitive functions such as working memory and inhibitory control (ie, motor-response and attentional inhibition) are linked to the anterior cruciate ligament (ACL) injury risk. Research has been conducted in laboratory settings, but the contribution of neurocognition to actual ACL injuries under real-world conditions is unknown.

OBJECTIVE

To describe the possible neurocognitive errors involved in noncontact ACL injury mechanisms.

DESIGN

Case series.

SETTING

Soccer matches.

PATIENTS OR OTHER PARTICIPANTS

A total of 47 professional male soccer players.

MAIN OUTCOME MEASURE(S)

Three independent reviewers evaluated 47 videos of players sustaining noncontact ACL injuries. Neurocognitive errors in inhibitory control were operationalized as follows: (1) motor-response inhibition was scored when a player demonstrated poor decision-making and approached the opponent with high speed that reduced the ability to stop or change the intended action and (2) an attentional error was scored when a player shifted his selective attention away from the relevant task to irrelevant stimuli.

RESULTS

Of 47 noncontact ACL injuries, 26 (55%) were related to a pressing-type injury, 19 (73%) of which involved a deceiving action made by the opponent, suggesting poor inhibitory control of the defender. Of the remaining 21 noncontact ACL injuries (45%), 16 (76%) could be attributed to attentional errors. Agreement among the 3 raters was very good for all items except poor decision-making, which showed fair to good agreement (Fleiss κ = 0.71). Interrater reliability was excellent (intraclass correlation coefficient = 0.99-1.00).

CONCLUSIONS

Errors in motor-response inhibitory control and attentional inhibition were common during noncontact ACL injury events in professional male soccer players. The interrater agreement in detecting neurocognitive errors in general was very good.

Practice reduces the costs of producing head fakes in basketball

Previous research indicates that performing passes with a head fake in basketball leads to increased response initiation times and errors as compared to performing a pass without a head fake. These so-called fake production costs only occurred when not given the time to mentally prepare the deceptive movement. In the current study, we investigated if extensive practice could reduce the cognitive costs of producing a pass with head fake. Twenty-four basketball novices participated in an experiment on five consecutive days. A visual cue prompted participants to play a pass with or without a head fake either to the left or right side. The cued action had to be executed after an interstimulus interval (ISI) of either 0 ms, 400 ms, 800 ms or 1200 ms, allowing for different movement preparation times. Results indicated higher response initiation times (ITs) and error rates (ERs) for passes with head fakes for the short preparation intervals (ISI 0 ms and 400 ms) on the first day but no difference for the longer preparation intervals (ISI 800 ms and 1200 ms). After only one day of practice, participants showed reduced fake production costs (for ISI 0 ms) and were even able to eliminate these cognitive costs when given time to mentally prepare the movement (for ISI 400 ms). Accordingly, physical practice can reduce the cognitive costs associated with head-fake generation. This finding is discussed against the background of the strengthening of stimulus response associations.

Timecourse of two-dimensional decision-making to offensive actions

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

The effectiveness of penalty takers' deception: A scoping review

Attackers are supposed to take advantage of producing deceptive actions in competitive ball sports, particularly in penalty situations. We conducted a scoping review of the experimental literature to scrutinize whether penalty takers do indeed benefit from using deceptive actions in penalty situations, especially by increasing the likelihood to score a goal. Studies using video-based and in-situ tasks in which soccer and handball goalkeepers try to save a penalty were evaluated. Results showed that penalty takers' manipulation of spatial information available to the goalkeeper during deception (i.e., by using misleading and/or disguising actions) is less effective in in-situ than video-based studies. We argue that this difference occurs because goalkeepers adapt differently to the spatiotemporal constraints in the video-based and in-situ tasks. Goalkeepers appear to prioritize picking up spatial information in video-based tasks while prioritizing temporal information in-situ tasks. Therefore, the manipulation of spatial information appears to be less effective in the more representative in-situ studies than in video-based studies. In order to deceive, penalty takers are advised to manipulate temporal information during on-field penalty situations.

Timing a fake punch: Inhibitory effects in a boxing-specific spatial attention task

The ability to respond quickly and accurately to spatial cues is of great importance to performance on any task where quick decision-making is required. The two main effects of spatial attention are priming, when a response to a target is facilitated after being cued at the same location, and inhibition of return (IOR), when the response to the target is slower to the cued area. Whether priming or IOR occurs is largely dependent on the length of the interval between the cue and the target. To determine whether these effects are relevant to dueling sports with deceptive actions we created a boxing-specific task that mimicked combinations of feints and punches. Altogether, we recruited 20 boxers and 20 non-boxers and found significantly longer reaction times to a punch thrown on the same side as a fake punch after a 600 ms interval, consistent with the IOR effect. We also found a moderate positive correlation between years of training and the magnitude of the IOR effect. This latter finding indicates that even athletes trained to avoid deception can be as susceptible as novices if the timing of the feint is right. Finally, our approach highlights the benefits of studying IOR using more sport specific settings, broadening the scope of the field.

Using Biological Motion to Investigate Perceptual-Cognitive Expertise in Law Enforcement Use-of-Force Decisions

Research focused on police officers' decision-making in ambiguous use-of-force situations has yet to investigate the role that a suspect's biological motion plays in unknown-object identification. The current study uses point-light displays to isolate the suspect's motion and remove potentially biasing information (e.g., skin tone, facial expression, clothing). Experienced law enforcement officers and trainees (n = 129) watched point-light display videos of an actor pulling either a weapon or a non-weapon from a concealed location in a threatening or non-threatening manner. After each video ended, participants indicated whether the object-which was not visible-was a weapon or a non-weapon. Results indicated that the speed and intent (e.g., threatening vs. non-threatening) with which the actor drew the object were significant predictors of officers' responses. Officers' law enforcement experience (i.e., years of service) was not a significant predictor of their response. This study has important implications for understanding why police sometimes make critical and costly errors in ambiguous use-of-force situations. We consider implications for police performance and developing improved training procedures.

Producing deceptive actions in sports: The costs of generating head fakes in basketball

Typically, head fakes in basketball are generated to, and actually do, deteriorate performance on the side of the observer. However, potential costs at the side of the producer of a fake action have only rarely been investigated before. It is thus not clear yet if the benefit (i.e., slowed reactions in the observer) of performing a head fake is overestimated due to concurrently arising fake production costs (i.e., slowed performance in the producer of a head fake). Therefore, we studied potential head-fake production costs with two experiments. Novice participants were asked to generate passes to the left or right side, either with or without head fakes. In Experiment 1, these actions were determined by an auditory stimulus (i.e., a 440 Hz or 1200 Hz sinus or jigsaw wave). After an interstimulus interval (ISI) of either 0 ms, 800 ms, or 1500 ms, which served the preparation of the action, the cued action had to be executed. In Experiment 2, passing to the left or right, either with or without a head fake, was determined by a visual stimulus (i.e., a player with a red or blue jersey defending either the right or left side). After an ISI of either 0 ms, 400 ms, 800 ms, or 1200 ms, the cued action had to be executed. In both experiments, we observed higher reaction times (RTs) for passes with head fakes as compared to passes without head fakes for no and an intermediate preparation interval (from ISI 0 ms to 800 ms), but no difference for a long preparation interval (for an ISI of 1200 ms and 1500 ms). Both experiments show that generating fake actions produces performance costs, however, these costs can be overcome by a longer preparation phase before movement execution.

Conocimiento de las tendencias de ataques rivales en el bloqueo de voleibol

El objetivo del estudio fue investigar los efectos de proporcionar información probabilística, obtenida del análisis en vídeo de las tendencias de pase de las colocadoras oponentes, sobre el rendimiento en el bloqueo de una jugadora de alto nivel de voleibol. Se analizó su tiempo de reacción, toma de decisión y calidad de ejecución durante 1117 acciones de bloqueo realizadas en 18 partidos de competición, antes y después de recibir esa información contextual de los ataques rivales. Los resultados revelaron que la bloqueadora reaccionó antes (p < .001) en aquellos partidos que recibió información sobre las tendencias de pase de las colocadoras oponentes. En cambio, esta información contextual no tuvo influencia sobre sus decisiones, ni en la calidad de ejecución de sus movimientos. Estos resultados refuerzan el uso de información probabilística como una estrategia competitiva para iniciar antes una respuesta preparatoria a la acción de bloqueo en voleibol de alto nivel.

Shot deception in basketball: Gaze and anticipation strategy in defence

Anticipation of teammates and opponents is a critical factor in many sports played in interactive environments. Deceptive actions are used in sports such as basketball to counteract anticipation of an opponent. In this study, we investigated the effects of shot deception on the players' anticipation behaviour in basketball. Thirty one basketball players (15 expert, 16 novice) watched life-sized videos of basketball players performing real shots or shot fakes aimed at the basket. Four different shot outcomes were presented in the video stimuli: a head fake, a ball fake, a high shot fake, and a genuine shot. The videos were temporally occluded at three different time points (-160 ms, -80 ms, 0 ms to ball release) during a shooting motion. The participants had to perform a basketball-related response action to either shots or shot fakes. Response accuracy, response time, and decision confidence were recorded along with gaze behaviour. Anticipation accuracy was reduced at later occlusion points for fake shooting actions. For expert athletes, this effect occurred at later occlusion points compared to novices. The gaze analysis of successful and unsuccessful shot anticipations revealed more gaze fixations towards the hip and legs in successful anticipations, whereas more fixations towards the ball and the head were found in shots unsuccessfully anticipated. It is proposed that hip and leg regions may contain causal information concerning the vertical trajectory of the shooter and identifying this information may be important for perceiving genuine and deceptive shots in basketball.

Humans utilize sensory evidence of others' intended action to make online decisions

We often acquire sensory information from another person's actions to make decisions on how to move, such as when walking through a crowded hallway. Past interactive decision-making research has focused on cognitive tasks that did not allow for sensory information exchange between humans prior to a decision. Here, we test the idea that humans accumulate sensory evidence of another person's intended action to decide their own movement. In a competitive sensorimotor task, we show that humans exploit time to accumulate sensory evidence of another's intended action and utilize this information to decide how to move. We captured this continuous interactive decision-making behaviour with a drift-diffusion model. Surprisingly, aligned with a 'paralysis-by-analysis' phenomenon, we found that humans often waited too long to accumulate sensory evidence and failed to make a decision. Understanding how humans engage in interactive and online decision-making has broad implications that spans sociology, athletics, interactive technology, and economics.

An Active Inference Account of Skilled Anticipation in Sport: Using Computational Models to Formalise Theory and Generate New Hypotheses

Optimal performance in time-constrained and dynamically changing environments depends on making reliable predictions about future outcomes. In sporting tasks, performers have been found to employ multiple information sources to maximise the accuracy of their predictions, but questions remain about how different information sources are weighted and integrated to guide anticipation. In this paper, we outline how predictive processing approaches, and active inference in particular, provide a unifying account of perception and action that explains many of the prominent findings in the sports anticipation literature. Active inference proposes that perception and action are underpinned by the organism’s need to remain within certain stable states. To this end, decision making approximates Bayesian inference and actions are used to minimise future prediction errors during brain–body–environment interactions. Using a series of Bayesian neurocomputational models based on a partially observable Markov process, we demonstrate that key findings from the literature can be recreated from the first principles of active inference. In doing so, we formulate a number of novel and empirically falsifiable hypotheses about human anticipation capabilities that could guide future investigations in the field.

Shot fakes as an indicator of successful offense in basketball

Past research has shown that tactical skills can increase the offensive output in basketball. Laboratory studies have confirmed this and indicated that fakes are useful, but their effectiveness is a function of expertise. In recent times, experts in the field have been able to correctly identify fakes with a higher accuracy. In this study, the primary objective was to investigate the offensive technical-tactical play shot fakes as a possible performance indicator in real basketball games. Furthermore, we evaluated how the attacker's initial offensive positioning and location on court influence the effectiveness of such shot fakes. We examined 45 NBA games using post-hoc video analyses. Though, on an average, a tenth of all points were scored after a shot fake, our data showed a significantly higher offensive effectiveness of possessions with a shot fake compared to the games' average for all offensive possessions. Moreover, shot fakes were found to be more effective being initially open, and were more often used when the focus player was being covered by a defender. In addition, 73% of all shot fakes were successful and advantageous for the attacker. This result, in conjunction with previous laboratory studies in which experts showed an above average probability of detection, points to the importance of time pressure for representative study designs. The evidence from this study proves that shot fakes are an important and effective offensive tool to gain an advantage over the opponent and increase offensive scoring, thereby setting the foundation for future research on shot fakes across sports.

Effect of Manipulating Advanced Kinematic Information on Hitting Movement Prediction, Perception, and Action

Purpose: This study examined the effect of manipulating advanced kinematic information about opponents' pitching movement on ball speed prediction, ball speed perception, and impact timing errors under strict temporal constraints (i.e., a softball game). Method: Three experiments were conducted using visual stimuli consisting of varied kinematic information-different pitching movements with the same ball trajectory. In Experiment 1, participants observed the pitching movement of the visual stimuli and predicted pitched ball speed as a two-interval forced choice discrimination task (2IFC). In Experiment 2, participants observed both the pitching movement and ball trajectory, and evaluated the pitched ball speed as a 2IFC. In Experiments 3a and 3b, they tried to swing against the pitched ball presented on the screen as accurately as possible with regard to timing. Results: Batters tended to predict the ball was moving faster when the pitching movement was faster (Experiment 1). Incorrectly predicting the ball speed due to the difference in advanced kinematic information also biased batters' perception of the speed (Experiment 2), and this biased prediction yielded congruent impact timing (Experiment 3a). The impact timing error of naive participants also was affected by kinematic information (Experiment 3b). Conclusion: Limitations of this study (representative task design, sample size, and experimental procedures) notwithstanding, results indicate that, under strict temporal constraints, batters' perceptions and actions are sensitive to advanced kinematic information, which could lead to biased perceptions and actions.

Earlier detection facilitates skilled responses to deceptive actions

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

The Effect of Judgement Bias on Cue Utilization for Shot Prediction in Basketball Athletes

BACKGROUND

Concerning the judgments bias and cue utilization in basketball athletes, previous shot anticipation tasks were hard to examine in regards to whether the experts' judgement bias relies more on the cue of the player's body or the ball trajectory.

METHODS

Four types of body-ball cues shots were employed: IN-IN, IN-OUT, OUT-IN, and OUT-OUT. Four temporal stages (i.e., shooting, rising, high point, and falling) were divided during a shot. Forty-two participants predicted the fate of the ball after watching the shot videos.

RESULTS

The results suggested that for the shooting, rising, and high point phase, compared to the non-athletes, the experts provided superior predictions for IN-IN condition and OUT-IN condition but fewer accurate predictions for IN-OUT condition and OUT-OUT condition. Moreover, a higher bias toward predicting the shots as "in" for the athletes than the non-athletes under early temporal conditions was confirmed.

CONCLUSIONS

These findings strengthen the idea that the IN cues from both body information and ball trajectory could elicit the experts' judgement bias for made shots and then influence their response, thus rendered two distinct (e.g., impeding and facilitating) effects for the incongruent body-ball cues, respectively.

A question of (perfect) timing: A preceding head turn increases the head-fake effect in basketball

In many kinds of sports, deceptive actions are frequently used to hamper the anticipation of an opponent. The head fake in basketball is often applied to deceive an observer regarding the direction of a pass. To perform a head fake, a basketball player turns the head in one direction, but passes the ball to the opposite direction. Several studies showed that reactions to passes with head fakes are slower and more error-prone than to passes without head fakes (head-fake effect). The aim of a basketball player is to produce a head-fake effect for as large as possible in the opponent. The question if the timing of the deceptive action influences the size of the head-fake effect has not yet been examined systematically. The present study investigated if the head-fake effect depends on the temporal lag between the head turn and the passing movement. To this end, the stimulus onset asynchrony between head turn, and pass was varied between 0 and 800 ms. The results showed the largest effect when the head turn precedes the pass by 300 ms. This result can be explained better by facilitating the processing of passes without head fake than by making it more difficult to process passes with a head fake. This result is discussed regarding practical implications and conclusions about the underlying mechanism of the head–fake effect in basketball are drawn.

Social bodies in virtual worlds: Intercorporeality in Esports

As screen-based virtual worlds have gradually begun facilitating more and more of our social interactions, some researchers have argued that the virtual worlds of these interactions do not allow for embodied social understanding. The aim of this article is to examine exactly the possibility of this by looking to esports practitioners' experiences of interacting with each other during performance. By engaging in an integration of qualitative research methodologies and phenomenology, we investigate the actual first-person experiences of interaction in the virtual worlds of the popular team-based esports practices Counter Strike: Global Offensive and League of Legends. Our analysis discloses how the practitioners' interactions essentially depend on intercorporeality - understood as a form of reciprocity of bodily intentionality between the players. This is an intercorporeality that is present throughout the players' performance, but which especially comes to the front when they engage in feinting. Acknowledging the intercorporeality integral to at least some esports practices helps fuzzying the sharp division between virtuality and embodied social understanding. Doing so highlights the fluidity of our embodied condition, and it raises interesting questions concerning the possibility of yet other forms of embodied sociality in a wider range of virtual formats in the world.

Testing the Effects of a Preceding Self-Control Task on Decision-Making in Soccer Refereeing

The present study tested the assumption that the momentary level of self-control strength affects the accuracy rates in a sports-related judgment and decision-making task. A total of N = 27 participants rated the veracity of 28 video-taped statements of soccer players who were interviewed by a non-visible referee after a critical game-related situation. In half of the videos, the players were lying, and in the other half, they were telling the truth. Participants were tested twice: once with temporarily depleted self-control strength and once with temporarily available self-control strength (order counterbalanced; measurements separated by exactly 7 days). Self-control strength was experimentally manipulated with the Stroop task. In line with two-process models of information processing, we hypothesized that under ego depletion, information is processed in a rather heuristic manner, leading to lower accuracy rates. Contrary to our expectations, the level of temporarily available self-control strength did not have an effect on accuracy rates. Limitations and implications for future research endeavors are discussed.

Examining the Perceptual-Cognitive Mechanism of Deceptive Actions in Sports

In several kinds of sports, deceptive actions are used to hinder the anticipation performance of an opponent. During a head fake in basketball, a player turns the head to one side but passes the ball to the other side. A pass with a head fake generates a head-fake effect in the observer, which is characterized by slower and more error-prone responses to the pass direction as compared to passes without a head fake. Whereas the head-fake effect has been replicated several times, the question of its origin with dynamic stimuli has not been answered yet. The present study includes four experiments, which are conducted to examine the perceptual-cognitive mechanism underlying the effect by using the model of dimensional overlap (Kornblum et al., 1990) and the additive factors logic (Sternberg, 1969). Results point to multiple processes contributing to the head-fake effect for dynamic stimuli, which operate not only at a perceptual level but also at a level of response selection.

Behavioral Measures in a Cognitive-Motor Batting Task Explain Real Game Performance of Top Athletes

Excellent athletic performance in baseball and softball batting is achieved through the momentary cognitive-motor processes. However, in previous studies, cognitive and motor processes are investigated separately. In this study, we focused on the difference in the time of swing onset (a delta onset) during a batting task where 17 elite female softball batters hit balls randomly thrown at two different speeds by pitchers. The delta onset included both cognitive and motor processes because the batters needed to anticipate the ball speed and discriminate their swing motion according to the time-to-contact. Then, we investigated the relationship between the delta onset and the batting outcomes of the batting task, and the relationship between the experimental outcomes and actual batting performance (batting average) over a season. We used path analysis to clarify the structure of the cognitive-motor processes and consequent performance. We found that the batters who had a larger delta onset attained superior batting outcomes (i.e., higher exit velocity and lower miss ratio) in the batting task, and these experimental outcomes explained 67% of the batting average in real games. On the other hand, the cognitive scores (judgement accuracy and rapidity) obtained from a button pressing task, where batters responded to a ball by pressing a button instead of actually swinging, explained only 34% of the batting average. Therefore, our model quantitatively describes the key cognitive-motor structure for athletes and can partially predict a batter's performance in real games. These findings suggest that it is important to employ both cognitive and motor processes in performing tasks, such as this batting task, to properly evaluate a batter's actual ability.

Social cues can impact complex behavior unconsciously

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.

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

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

"Are You Telling the Truth?" - Testing Individuals' Ability to Differentiate Between Truth and Deceit in Soccer

In the present paper, we tested the ability of individuals to judge correctly whether athletes are lying or telling the truth. For this purpose, we first generated 28 videos as stimulus material: in half of the videos, soccer players were telling the truth, while in the other half, the same soccer players were lying. Next, we tested the validity of these video clips by asking N = 65 individuals in a laboratory experiment (Study 1a) and N = 52 individuals in an online experiment (Study 1b) to rate the level of veracity of each video clip. Results suggest that participants can distinguish between true and false statements, but only for some clips and not for others, indicating that some players were better at deceiving than others. In Study 2, participants again had to make veracity estimations, but we manipulated the level of information given, as participants (N = 145) were randomly assigned to one of three conditions (regular video clips, mute video clips, and only the audio stream of each statement). The results revealed that participants from the mute condition were less accurate in their veracity ratings. The theoretical and practical implications of these findings are discussed.

Cognitive load reduces interference by head fakes in basketball

The head fake in basketball is a deceptive action in sports, where an attacking basketball player gazes in one direction (irrelevant component), but passes the ball to the opposite direction (relevant component). A defending player, who aims to respond to the relevant information displayed by the opponent, faces a situation conceptually similar to well-known interference paradigms (e.g., Stroop task, Eriksen flanker task). Previous research has shown that responses to pass directions are slower and more error prone for head fakes than for direct passes (so called head-fake effect). The head-fake effect depends on participants' ability to focus attention on the relevant stimulus feature. As maintaining this attentional focus conceivably bears on limited capacities, we tested if taxing these capacities by a cognitively demanding concurrent task would change the impact of task-irrelevant information and thus, the size of the head-fake effect. Moreover, we investigated the impact of such a concurrent task on post-conflict control (i.e., the congruency sequence effect). The results show that a concurrent task reduces the head-fake effect, while post-conflict control was unaffected. We discuss these findings with regard to the relationship of working memory processes and selective attention.

The last chance to pass the ball: investigating the role of temporal expectation and motor resonance in processing temporal errors in motor actions

Humans can acquire information on others' motor outputs (action prediction) and intentions (action understanding) according to their individual motor repertoire and to the detected gesture's features (e.g. temporal patterns). We aimed at dissociating between action prediction and action understanding abilities in soccer players and novices observing soccer action videos including correct timing pass (CTP) or delayed pass (DP). First, we used an occluding paradigm to evaluate participants' ability to predict the correct time to pass the ball. Although soccer players showed reduced reaction times, all subjects showed a similar pattern of performance: during DP observation, responses appeared delayed with respect to the other conditions but anticipated with respect to the observed DP. In a separate experiment, we investigated the ability to recognize CTP vs DP and the modulation of primary motor cortex (M1) excitability associated to video observation. Only soccer players showed selective modulation of M1 according to the plausibility of the observed action, with increased excitability during the observation of the CTP and in a phase preceding the DP. In conclusion, action prediction ability seems to be independent from the individual motor repertoire. By contrast, only subjects with previously acquired sensorimotor skills are able to infer the observed action's long-term intention.

Extending Research on Deception in Sport - Combining Perception and Kinematic Approaches

The spatio-temporal demands of many high performance sport contexts require a strategic interplay between anticipation from early kinematic cues and the appropriate movement strategy. Despite the importance of the interaction between observer and deceiver in these contexts, this dyad is usually considered separately (i.e., from perceptual-cognitive or kinematic perspectives). The present approach proposes a consolidation of perceptual-cognitive and kinematic perspectives into a dyad of deception that focuses on the interplay between opposing actors within antagonistic contexts. A framework is proposed for analyzing movement deception within this dyad. Applying a functional approach, the deceptive act is positioned as a means of optimally solving an antagonistic performance task with high spatio-temporal demands. The framework involves three elements: first, the context of the movement deception is evaluated relative to the constraints imposed by the athlete, object, and deceptive content. Together, these constraints generate a range of potential kinematic options for movement deception. Second, movement deception is determined by the spatio-temporal constraints of the original context. More simply, misleading information is only useful if it mimics elements of the genuine movement. Third, the framework emphasizes targeting the spatio-temporal interplay as well as differentiating between active and co(ntra)-active movement deception. Our goal with this framework is to supplement movement deception research by providing a conceptional context that can be applied across sports.

Detection of deceptive motions in rugby from visual motion cues

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.

On the ball: Short-term consequences of movement fakes

In competitive situations, humans sometimes use fake actions. Fake actions are carried out to pretend a certain action goal, which however is not actually pursued, such as pump fakes in basketball, or drop shots in tennis. Here, we studied the short-term consequences of producing or observing fakes on the planning and detection of subsequent fake actions. Two players participated in a game, an attacker and a defender. Attackers had to either throw a ball into a target basket of the defender, or to mimic such a throw without actually throwing. Defenders had to discriminate between real throws and faked throws. Participants changed the roles of attacker and defender, and switched between real and faked throws randomly, on a trial-by-trial basis. We found that the (self-)observation of a fake action facilitated the detection of subsequent fake actions of opponents, but did not facilitate the subsequent planning of own fake actions. We conjecture that previous encounters of fake actions help to focus on the movement aspects that are most diagnostic for such fake actions. As a potential practical consequence, we recommend to not generate multiple fake actions in sports within a short time, to prevent potential short-term perceptual adaptation effects of defenders.

Is the head-fake effect in basketball robust against practice? Analyses of trial-by-trial adaptations, frequency distributions, and mixture effects to evaluate effects of practice

Reactions to the pass of a basketball player performing a head fake are typically slower than reactions to a basketball player who passes without a head fake (i.e., head-fake effect). The present study shows that extensive practice reduces the head-fake effect in basketball. Additional analyses were conducted to explore the mechanism behind the reduced head-fake effect. First, we analyzed whether or not participants developed some control over the processing of irrelevant gaze direction, as indicated by specific trial-to-trial adaptations (i.e., congruency sequence effect). Second, we fitted the individual frequency distributions of RTs to ex-Gaussian distributions, to evaluate if practice specifically affects the Gaussian part of the distribution or the exponential part of the distribution. Third, we modeled individual RT distributions as the so-called mixture effects to examine whether the way irrelevant gaze direction impacts performance (either occasionally but massively or continuously but moderately) changes with practice. The analyses revealed that the effect of practice could not be explained with an increasing congruency-sequence effect. Also, it could not be found in the ex-Gaussian distributional analyses. The assumption that residual failure to inhibit the processing of the gaze direction in contrast to continuous failures to do so might favor mixed effects over uniform effects at later courses of practice could not be validated. The reduced head-fake effect thus is argued to source in participants' general increasing ability to inhibit the processing of the task-irrelevant gaze direction information and/or in a priority shift of gaze processing to a processing of the pass direction.

Where Are You Throwing the Ball? I Better Watch Your Body, Not Just Your Arm!

The ability to intercept or avoid a moving object, whether to catch a ball, snatch one's prey, or avoid the path of a predator, is a skill that has been acquired throughout evolution by many species in the animal kingdom. This requires processing early visual cues in order to program anticipatory motor responses tuned to the forthcoming event. Here, we explore the nature of the early kinematics cues that could inform an observer about the future direction of a ball projected with an unconstrained overarm throw. Our goal was to pinpoint the body segments that, throughout the temporal course of the throwing action, could provide key cues for accurately predicting the side of the outgoing ball. We recorded whole-body kinematics from twenty non-expert participants performing unconstrained overarm throws at four different targets placed on a vertical plane at 6 m distance. In order to characterize the spatiotemporal structure of the information embedded in the kinematics of the throwing action about the outgoing ball direction, we introduced a novel combination of dimensionality reduction and machine learning techniques. The recorded kinematics clearly shows that throwing styles differed considerably across individuals, with corresponding inter-individual differences in the spatio-temporal structure of the thrower predictability. We found that for most participants it is possible to predict the region where the ball hit the target plane, with an accuracy above 80%, as early as 400-500 ms before ball release. Interestingly, the body parts that provided the most informative cues about the action outcome varied with the throwing style and during the time course of the throwing action. Not surprisingly, at the very end of the action, the throwing arm is the most informative body segment. However, cues allowing for predictions to be made earlier than 200 ms before release are typically associated to other body parts, such as the lower limbs and the contralateral arm. These findings are discussed in the context of the sport-science literature on throwing and catching interactive tasks, as well as from the wider perspective of the role of sensorimotor coupling in interpersonal social interactions.

Aiming to Deceive: Examining the Role of the Quiet Eye During Deceptive Aiming Actions

In three experiments, we explored the use of deceptive gaze in soccer penalty takers using eye-tracking equipment. In Experiment 1, players competed against a goalkeeper while taking unconstrained shots. Results indicated that when players used deception (looking to the opposite side to which they shot), they extended the duration of their final aiming (quiet eye) fixation and maintained shooting accuracy. In Experiment 2, with no goalkeeper present, players still used extended quiet-eye durations when using a deceptive strategy, but this time, their accuracy suffered. In Experiment 3, we manipulated the goalkeeper's location while controlling for the use of peripheral vision and memory of goal size. Results indicated that increased quiet-eye durations were required when using deceptive aiming, and that accuracy was influenced by the position of the goalkeeper. We conclude that during deceptive aiming, soccer players maintain accuracy by covertly processing information related to the goalkeeper's location.