Stepovers and Signal Detection: Response Sensitivity and Bias in the Differentiation of Genuine and Deceptive Football Actions

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.

Decision-making in action: How international-level professional football players gain an advantage

Understanding how both visual and contextual in-game information influences player's attempts to gain an advantage over their opponent is key to understanding skilled decision-making in fast-ball sports. In the present study, we conducted semi-structured interviews with 15 male professional football players to explore their reported behaviours and perspectives on their in-game decision-making and the ways in which they adapt to gain an advantage over their opponent. Professional players who have competed internationally at either Under 17, Under 19, Under 21, or senior level took part in semi-structured interviews. The data were analysed using reflexive thematic analysis which generated four higher-order themes about players reported behaviours and perspectives on their decision-making and ways of gaining an advantage: (i) being "unpredictable"; (ii) option generation and invitation, comprising two sub-themes: (iia) generating and realising options in action; and (iib) act on what invites you in the moment; (iii) anticipation and awareness; and (iv) dictating and controlling the game. A key finding was that players attempts to gain an advantage were largely grounded in the aim of 'being unpredictable' through the use of deception and disguise, as well as deliberate manipulation of action sequences in order to make their actions 'hard to read'. A further important finding was that players do not always seek a universal optimal decision, as their individual action capabilities influence their available options. These findings have important implications for the assessment of decision-making performance in future empirical research.

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.

Evaluation of multi-directional speed qualities throughout adolescence in youth soccer: The non-linear nature of transfer

Training and assessment of agility is often prioritised by soccer coaches and practitioners aiming to develop multi-directional speed. Although the importance of agility is advocated throughout childhood and adolescence, limited data evidence agility performance at different stages of adolescence. The purpose of this study was to examine differences in multi-directional speed performance in youth soccer players spanning an entire soccer academy. A total of 86 male junior-elite soccer players volunteered to participate. Anthropometric data were collected, alongside performance data from a battery of physical tests including sprinting, jumping, change of direction, reaction time, and agility. Bayesian models using log-likelihoods from posterior simulations of parameter values displayed linear or curvilinear relationships between both chronological and biological age and performance in all tests other than agility and reaction time. For agility and reaction time tests, performance improved until ~14 years of age or the estimated age of peak height velocity whereby arrested development in performance was observed. Our results demonstrate that while most performance skills improve as chronological or biological age increases, measures of agility and reaction time may not. These findings support the notion that agility performance is complex and multifaceted, eliciting unique, challenging physical demands and non-linear development.

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.

Action outcome probability influences the size of the head-fake effect in basketball

Both kinematic and contextual information (e.g., action outcome probability) play a significant role in action anticipation. However, few researchers have examined the reciprocal influence of the two types of information and fewer still have investigated this issue for deceptive actions in sports. In the present study, we investigate the impact of action outcome probability on the processing of deceptive kinematic cues for the head fake in basketball. We manipulated the probability of the action outcome to either pass the ball to the left or to the right side (i.e., 75%, 50%, 25%) and examined how this contextual information affected the influence of head orientation on pass direction judgments. Outcome probability information was either provided explicitly (Experiment 1) or implicitly (Experiment 2). Both experiments indicated an increased head-fake effect with increasing outcome probability. Moreover, the bias to respond in line with the player's head direction increased linearly with outcome probability. Also, discriminability between deceptive and genuine actions was poorer for high outcome probability (75%) associated with head orientation than for the 25% and 50% values. Last, a stronger response bias toward the higher probability side for deceptive trials than for genuine trials was only significant when the outcome probability information was processed implicitly in Experiment 2. The results of this study fit well with recent literature on contextual information in action prediction and are discussed in light of confirmation bias and signal detection theory.

Maximising Grip on Deception and Disguise: Expert Sports Performance During Competitive Interactions

Expert performers in fast-ball and combat sports continuously interact with their opponents and, if they are to be successful, adapt behaviour in order to gain an advantage. For example, disguise and deception are recognised as skilful behaviours that are employed to disrupt an opponent’s ability to successfully anticipate their actions. We contend that such skilled behaviour unfolds during the interaction between opposing players, yet typical research approaches omit and/or artificially script these interactions. To promote the study of skilled behaviour as it emerges during competitive interactions, we offer an account informed by contemporary ecological perspectives for shaping investigation into how deception and disguise can be used to gain an advantage over an opponent and the challenges it poses to anticipation. We propose that each player attempts to develop maximum grip on the interaction through exploiting information across multiple timescales to position themselves as to facilitate openness to relevant affordances. The act of deception can be understood as offering a misleading affordance that an opponent is invited to act on, imposing a significant challenge to an opponent’s ability to attain grip by manipulating the information available. Grounded in our ecological perspective, we emphasise the need for future investigation into: (1) the role of disguise for disrupting anticipation; (2) how deception can be employed to gain an advantage by manipulating information on multiple timescales, before detailing; (3) how opposing performers go beyond merely exploiting information and actively elicit information to deal with deception and disguise during an interaction.

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

SIGNIFICANCE

Visual anticipation is vital for performance in several domains such as driving, military, and high-speed interceptive sports, as it enables performers to handle severe time constraints. There has been little investigation into individual differences of anticipation skill transfer within a domain, which can guide training of anticipation to improve performance.

PURPOSE

The purpose of this study was to investigate individual differences in the transfer of anticipation within a domain, specifically anticipation of the field hockey penalty corner drag-flick across different opponents.

METHODS

Eight female Australian international and national field hockey goalkeepers participated. Goalkeepers completed female and male opponent penalty corner drag-flick temporal occlusion tests that presented contextual defensive runner positioning relative to the penalty spot, drag-flicker kinematics, and ball flight.

RESULTS

Drag-flick movement time and ball velocity were significantly different across female and male opponents confirming that a transfer continuum existed. Five goalkeepers could transfer integration of runner contextual and drag-flicker kinematic information to anticipate loose runs above chance from female to male opponent tests. None of the goalkeepers could transfer integration of contextual and kinematic information for the tight runs across female to male opponents.

CONCLUSIONS

An individual differences approach with truly expert performers provided unique insights into the mechanism of anticipation transfer within a domain. The findings of this study contribute to theoretical and applied knowledge, which can guide the training of anticipation skill to prepare individuals for superior performance.

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.

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.

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.