David L. Mann

Action specificity increases anticipatory performance and the expert advantage in natural interceptive tasks

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.

The head tracks and gaze predicts: how the world's best batters hit a ball

Hitters in fast ball-sports do not align their gaze with the ball throughout ball-flight; rather, they use predictive eye movement strategies that contribute towards their level of interceptive skill. Existing studies claim that (i) baseball and cricket batters cannot track the ball because it moves too quickly to be tracked by the eyes, and that consequently (ii) batters do not – and possibly cannot – watch the ball at the moment they hit it. However, to date no studies have examined the gaze of truly elite batters. We examined the eye and head movements of two of the world’s best cricket batters and found both claims do not apply to these batters. Remarkably, the batters coupled the rotation of their head to the movement of the ball, ensuring the ball remained in a consistent direction relative to their head. To this end, the ball could be followed if the batters simply moved their head and kept their eyes still. Instead of doing so, we show the elite batters used distinctive eye movement strategies, usually relying on two predictive saccades to anticipate (i) the location of ball-bounce, and (ii) the location of bat-ball contact, ensuring they could direct their gaze towards the ball as they hit it. These specific head and eye movement strategies play important functional roles in contributing towards interceptive expertise.

Does Visual-Perceptual Training Augment the Fielding Performance of Skilled Cricketers?

This study examined the effectiveness of visual-perceptual training for improving fielding performance in cricket. Twelve highly-skilled cricket players completed a video-based decision-making test and an in-situ fielding test before and after a six-week training intervention. During this period, all participants completed the same on-field training program, but seven players completed three additional perceptual training sessions per week (TRAIN). The remaining five players acted as a control (CON). Despite no group differences at pre-test, TRAIN scored significantly higher than CON at post-test for decision accuracy within the video-based test. For the in-situ fielding test, TRAIN demonstrated greater improvements in fielding success following the intervention compared to CON. The results indicate that six weeks of on-field training combined with visual-perceptual training can lead to improvements in the fielding performance of skilled cricketers above those of on-field training alone. Findings are discussed from empirical and applied coaching perspectives.

The resilience of natural interceptive actions to refractive blur

The impact of refractive visual blur on interceptive skill was examined for a series of highly-demanding striking tasks. Ten skilled cricket batsmen were required to intercept balls projected by either a ball projection-machine (medium-pace only) or cricket bowlers (two velocities; medium-pace and fast-pace) under each of four systematically varied visual conditions. Contact lenses were fitted to simulate increments in refractive blur (habitual, +1.00, +2.00, +3.00D), with changes in interceptive performance evaluated on three concurrent measures of performance relevant to cricket batting (quality of bat-ball contact, forcefulness of bat-swing, and likelihood of dismissal). For the projection-machine condition, results replicate those reported previously (Mann, Ho, De Souza, Watson, & Taylor, 2007) with blur needing to reach +3.00D before any significant decreases in performance were evident, a finding further replicated when facing bowlers of comparable velocity. The influence of blur on interception was found to interact with ball-velocity, with the increased temporal demands of fast-paced trials resulting in decreased performance becoming evident at a lower level of blur (+2.00D). The findings demonstrate that even when presented with a situation replicating highly-demanding performance conditions, substantial degradation of visual clarity is possible before acuity is a limiting factor for interceptive performance.

Guiding Attention Aids the Acquisition of Anticipatory Skill in Novice Soccer Goalkeepers

Purpose: The ability to anticipate the actions of opponents can be enhanced through perceptual-skill training, though there is doubt regarding the most effective form of doing so. We sought to evaluate whether perceptual-skill learning would be enhanced when supplemented with guiding visual information. Method: Twenty-eight participants without soccer-playing experience were assigned to a guided perceptual-training group (n = 9), an unguided perceptual-training group (n = 10), or a control group (n = 9). The guided perceptual-training group received half of their trials with color cueing that highlighted either the key kinematic changes in the kickers action or the known visual search strategy of expert goalkeepers. The unguided perceptual-training group undertook an equal number of trials of practice, but all trials were without guidance. The control group undertook no training intervention. All participants completed an anticipation test immediately before and after the 7-day training intervention, as well as a 24-hr retention test. Results: The guided perceptual-training group significantly improved their response accuracy for anticipating the direction of soccer penalty kicks from preintervention to postintervention, whereas no change in performance was evident at posttest for either the unguided perceptual-training group or the control group. The superior performance of the guided perceptual-training group was preserved in the retention test and was confirmed when relative changes in response time were controlled using a covariate analysis. Conclusions: Perceptual training supplemented with guiding information provides a level of improvement in perceptual anticipatory skill that is not seen without guidance.

Time to broaden the scope of research on anticipatory behavior: a case for the role of probabilistic information

Over the past four decades we have seen a dramatic improvement in our understanding of the processes that underpin the anticipatory behavior of skilled performers in domains such as sport. Early research by Jones and Miles (1978) and Salmela and Fiorito (1979) inspired and fuelled the research of todays leaders in the field such as Abernethy (1990), Savelsbergh et al. (2002), and Williams and Davids (1998), and many of us who follow in their footsteps. Originally, the key question driving this research was whether skilled performers of temporally constrained sport tasks (e.g., returning a tennis serve or hitting a baseball) are better than less-skilled performers in their ability to make use of kinematic information from an opponents action. After confirming the expert advantage in anticipation, research then focused on identifying the kinematic sources of information that underpin the superior anticipatory behavior. This research made use of a variety of experimental paradigms including temporal and spatial occlusion techniques, point-light displays, and gaze tracking (for a review see Mann and Savelsbergh, 2015). Since the 1970s an impressive body of empirical data has been generated that has led to useful practical outcomes for the individual sports examined, and that at the same time have resulted in more generalizable findings across sports, thereby generating a better understanding of the mechanisms underlying expert anticipation. As a case in point, it is now generally accepted that experts tend to make use of fewer fixations of longer duration when trying to predict the outcome of an opponents action (for a meta-analysis supporting this conclusion, see e.g., Mann et al., 2007). There can be little doubt that this research focusing on the kinematic sources of information that facilitate the prediction of action outcomes has proven to be very insightful and important for furthering our understanding of expert anticipation in sports (Abernethy, 1990; Williams and Davids, 1998). Likewise, this research has been crucial for generating evidence-based recommendations for the best means to train anticipatory skill. However, here we call for a broadening in the scope of anticipation research in an attempt to further improve and enrich our understanding of expert anticipation in sport. This call is based on the high proportion of studies performed examining anticipatory behavior on the basis of kinematic sources of information, yet a relative paucity in studies that take into consideration the influence of broader situational or contextual (non-kinematic) sources of information. As early as in the late 1970s researchers identified that anticipatory behavior may at least in part be informed by probabilistic information that is independent of the observed movement, and hence also independent of the visual information that can be picked up from such movements (e.g., Alain and Girardin, 1978; Alain and Proteau, 1980). It was Abernethy et al. (2001) who—more than 20 years after the original observations had been published—revisited how other non-kinematic, contextual information may contribute and influence how experts anticipate action outcomes. In their seminal paper, Abernethy et al. (2001) showed that probabilistic information that they coined situational probabilities could be used to anticipate action outcomes in the absence of any movement information from the opponent (in that case by evaluating the court position of the opponent in squash). Since then, only recently have a handful of studies started to systematically examine the contribution of situational probability (or contextual) information to anticipatory behavior. This includes the impact of probabilistic information such as playing patterns related to the game score (Farrow and Reid, 2012); exposure to an individuals action preferences (Navia et al., 2013; Mann et al., 2014); exposure to previous outcome sequences (Loffing et al., 2015); how an opponents court position interacts with kinematically-driven judgments (Loffing and Hagemann, 2014); and how contextual information influences both gaze behavior (McRobert et al., 2011) and the cognitive processes underpinning anticipatory skill (Murphy et al., 2015). Moreover, it has been shown that the anticipatory behavior of skilled performers is influenced by their assessment of the relative costs and benefits of responding or not responding (Canal-Bruland and Schmidt, 2009; Canal-Bruland et al., 2015). Further, work on the use of simple heuristics also indicates that experts tend to use various sources of information to make fast judgments under conditions of uncertainty that in sports include situations which require the initiation of action responses even before reliable visual information is available (Raab, 2012; de Oliveira et al., 2014). Together, these findings strongly support the idea that factors other than visual information conveyed in the observed kinematics do also play a significant role in successful anticipatory behavior. Given that these recent studies have highlighted a surprisingly large role for contextual information in supporting anticipatory behavior, we advocate that more research is needed in this area to bring us closer to the original aim, namely, to understand the superior anticipatory skill of experts. To reach this ultimate objective, in our view, research is needed to identify: (1) the contextual (non-kinematic) sources of information that influence anticipatory behavior; (2) how skilled performers combine these non-kinematic contextual sources of information with (i) each other and (ii) with real-time (kinematic) information from an opponents actions; and (3) how the way that the information is combined is shaped by the circumstances in which the behavior is performed.

The role of central and peripheral vision in expert decision making

The purpose of this study was to investigate the role of central and peripheral vision in expert decision making. A gaze-contingent display was used to selectively present information to the central and peripheral areas of the visual field while participants performed a decision-making task. Eleven skilled and eleven less-skilled male basketball players watched video clips of basketball scenarios in three different viewing conditions: full-image control, moving window (central vision only), and moving mask (peripheral vision only). At the conclusion of each clip participants were required to decide whether it was more appropriate for the ball-carrier to pass the ball or to drive to the basket. The skilled players showed significantly higher response accuracy and faster response times compared with their lesser-skilled counterparts in all three viewing conditions, demonstrating superiority in information extraction that held irrespective of whether they were using central or peripheral vision. The gaze behaviour of the skilled players was less influenced by the gaze-contingent manipulations, suggesting they were better able to use the remaining information to sustain their normal gaze behaviour. The superior capacity of experts to interpret dynamic visual information is evident regardless of whether the visual information is presented across the whole visual field or selectively to either central or peripheral vision alone.

Visual information underpinning skilled anticipation: The effect of blur on a coupled and uncoupled in situ anticipatory response.

Coupled interceptive actions are understood to be the result of neural processing—and visual information— which is distinct from that used for uncoupled perceptual responses. To examine the visual information used for action and perception, skilled cricket batters anticipated the direction of balls bowled toward them using a coupled movement (an interceptive action that preserved the natural coupling between perception and action) or an uncoupled (verbal) response, in each of four different visual blur conditions (plano, +1.00, +2.00, +3.00). Coupled responses were found to be better than uncoupled ones, with the blurring of vision found to result in different effects for the coupled and uncoupled response conditions. Low levels of visual blur did not affect coupled anticipation, a finding consistent with the comparatively poorer visual information on which online interceptive actions are proposed to rely. In contrast, some evidence was found to suggest that low levels of blur may enhance the uncoupled verbal perception of movement.

Gaze-contingent training enhances perceptual skill acquisition

The purpose of this study was to determine whether decision-making skill in perceptual-cognitive tasks could be enhanced using a training technique that impaired selective areas of the visual field. Recreational basketball players performed perceptual training over 3 days while viewing with a gaze-contingent manipulation that displayed either (a) a moving window (clear central and blurred peripheral vision), (b) a moving mask (blurred central and clear peripheral vision), or (c) full (unrestricted) vision. During the training, participants watched video clips of basketball play and at the conclusion of each clip made a decision about to which teammate the player in possession of the ball should pass. A further control group watched unrelated videos with full vision. The effects of training were assessed using separate tests of decision-making skill conducted in a pretest, posttest, and 2-week retention test. The accuracy of decision making was greater in the posttest than in the pretest for all three intervention groups when compared with the control group. Remarkably, training with blurred peripheral vision resulted in a further improvement in performance from posttest to retention test that was not apparent for the other groups. The type of training had no measurable impact on the visual search strategies of the participants, and so the training improvements appear to be grounded in changes in information pickup. The findings show that learning with impaired peripheral vision offers a promising form of training to support improvements in perceptual skill.

The contributions of central and peripheral vision to expertise in basketball: how blur helps to provide a clearer picture

The main purpose of this study was to examine the relative roles of central and peripheral vision when performing a dynamic forced-choice task. We did so by using a gaze-contingent display with different levels of blur in an effort to (a) test the limit of visual resolution necessary for information pick-up in each of these sectors of the visual field and, as a result, to (b) develop a more natural means of gaze-contingent display using a blurred central or peripheral visual field. The expert advantage seen in usual whole field visual presentation persists despite surprisingly high levels of impairment to central or peripheral vision. Consistent with the well-established central/peripheral differences in sensitivity to spatial frequency, high levels of blur did not prevent better-than-chance performance by skilled players when peripheral information was blurred, but they did affect response accuracy when impairing central vision. Blur was found to always alter the pattern of eye movements before it decreased task performance. The evidence accumulated across the 4 experiments provides new insights into several key questions surrounding the role that different sectors of the visual field play in expertise in dynamic, time-constrained tasks.