Pistol shooting performance under pressure: Longitudinal changes in gaze behavior of male and female Army cadets

We found evidence that Army cadets improved their gaze behavior and performance across time under high and low pressure in a shooting task. The purpose of the study was to determine if male and female cadets developed an optimal quiet eye (QE) onset, a longer QE duration, and decreased pupil diameter variability (PDV) over time under low (LP) and high pressure (HP) conditions. The study was carried out over four sessions, with intervals of 4.5 months. During each session, 16 men and 12 women, first-year cadets of The Brazilian Army Academy, performed ten pistol shots under counterbalanced LP and HP conditions. The cadets shot in the upright position and wore an eye-tracker. Shooting accuracy improved and did not differ for men and women in the LP condition, however during HP the women performed more poorly than the men in session 1 but improved to a level similar to the men in session 4. QE duration Pre (aiming) did not differ during LP, while during HP QE Post (execution) increased across the session for men and women. QE onset 2 (execution) occurred earlier for the men than women during LP, while during HP the women improved to a level similar to the men in sessions 3 and 4. PDV declined across sessions for men and women with the lowest values in sessions 3 and 4. The findings are discussed within social facilitation theory, which states the context of training affects the rate at which improvements in motor skills occur. The results show that women cadets can improve their shooting performance, quiet eye duration, quiet eye onset and pupil diameter variability to a level similar to men if three to four LP and HP training sessions are scheduled across approximately 12-18 months.

Building a transdisciplinary expert consensus on the cognitive drivers of performance under pressure: An international multi-panel Delphi study

Introduction

The ability to perform optimally under pressure is critical across many occupations, including the military, first responders, and competitive sport. Despite recognition that such performance depends on a range of cognitive factors, how common these factors are across performance domains remains unclear. The current study sought to integrate existing knowledge in the performance field in the form of a transdisciplinary expert consensus on the cognitive mechanisms that underlie performance under pressure.

Methods

International experts were recruited from four performance domains [(i) Defense; (ii) Competitive Sport; (iii) Civilian High-stakes; and (iv) Performance Neuroscience]. Experts rated constructs from the Research Domain Criteria (RDoC) framework (and several expert-suggested constructs) across successive rounds, until all constructs reached consensus for inclusion or were eliminated. Finally, included constructs were ranked for their relative importance.

Results

Sixty-eight experts completed the first Delphi round, with 94% of experts retained by the end of the Delphi process. The following 10 constructs reached consensus across all four panels (in order of overall ranking): (1) Attention; (2) Cognitive Control-Performance Monitoring; (3) Arousal and Regulatory Systems-Arousal; (4) Cognitive Control-Goal Selection, Updating, Representation, and Maintenance; (5) Cognitive Control-Response Selection and Inhibition/Suppression; (6) Working memory-Flexible Updating; (7) Working memory-Active Maintenance; (8) Perception and Understanding of Self-Self-knowledge; (9) Working memory-Interference Control, and (10) Expert-suggested-Shifting.

Discussion

Our results identify a set of transdisciplinary neuroscience-informed constructs, validated through expert consensus. This expert consensus is critical to standardizing cognitive assessment and informing mechanism-targeted interventions in the broader field of human performance optimization.

The Role of Quiet Eye Timing and Location in the Basketball Three-Point Shot: A New Research Paradigm

We investigated three areas of uncertainty about the role of vision in basketball shooting, the timing of fixations (early, late), the location of fixations (hoop centre, non-centre) and the effect of the defender on performance. We also sought to overcome a limitation of past quiet eye studies that reported only one quiet eye (QE) period prior to a phase of the action. Elite basketball players received the pass and took three-point shots in undefended and defended conditions. Five sequential QE periods were analyzed that were initiated prior to each phase of the shooting action: QE catch, QE arm preparation, QE arm flexion, QE arm extension, and QE ball release. We used a novel design in which the number of hits and misses were held constant by condition, thus leaving the timing and location of QE fixations free to vary across the phases during an equal number of successful and unsuccessful trials. The number of QE fixations accounted for 87% of total fixations. The greatest percent occurred during QE catch (43.6%), followed by QE arm flexion (34.1%), QE arm extension (17.5%) and QE ball release (4.8%). No fixations were found prior to QE arm preparation, due to a saccade made immediately to the target after QE catch. Fixation frequency averaged 2.20 per trial, and 1.25 during the final shooting action, meaning that most participants had time for only one fixation as the shot was taken. Accuracy was enhanced when: (1) an early QE offset occurred prior to the catch, (2) an early saccade was made to the target, (3) a longer QE duration occurred during arm flexion, and (4) QE arm flexion was located on the centre of the hoop, rather than on non-centre locations. Overall, the results provide evidence that vision of the hoop was severely limited during the last phase of the shooting action (QE ball release). The significance of the results is explored in the discussion, along with a QE training program designed to improve three-point shooting. Overall, the results greatly expand the role of the QE in explaining optimal motor performance.

A randomized controlled trial of a group-based gaze training intervention for children with Developmental Coordination Disorder

The aim of this study was to integrate a gaze training intervention (i.e., quiet eye training; QET) that has been shown to improve the throwing and catching skill of children with Developmental Coordination Disorder (DCD), within an approach (i.e., group therapy) that might alleviate the negative psychosocial impact of these motor skill deficits. Twenty-one children with DCD were split into either QET (8 male 3 female, mean age of 8.6 years (SD = 1.04) or technical training (TT) groups (7 male 3 female, mean age of 8.6 years (SD = 1.84). The TT group were given movement-related instructions via video, relating to the throw and catch phases, while the QET group were also taught to fixate a target location on the wall prior to the throw (QE1) and to track the ball prior to the catch (QE2). Each group partook in a 4-week, group therapy intervention and measurements of QE duration and catching performance were taken before and after training, and at a 6-week delayed retention test. Parental feedback on psychosocial and motor skill outcomes was provided at delayed retention. Children improved their gaze control and catching coordination following QET, compared to TT. Mediation analysis showed that a longer QE aiming duration (QE1) predicted an earlier onset of tracking the ball prior to catching (QE2) which predicted catching success. Parents reported enhanced perceptions of their child’s catching ability and general coordination in the QET group compared to the TT group. All parents reported improvements in their child’s confidence, social skills and predilection for physical activity following the trial. The findings offer initial support for an intervention that practitioners could apply to address deficits in the motor and psychosocial skills of children with DCD.

Trial registration: ClinicalTrials.govNCT02904980

Effect of the look-up line on the gaze and head orientation of elite ice hockey players

A "look-up line" (LUL) has been proposed for ice hockey, which is an orange 1 m (40') warning line (WL) painted on the ice at the base of the boards. The LUL purports to provide an early warning to players to keep their head up prior to and as they are being checked. We determined if players looked up more on a rink with the LUL compared to a traditional Control rink. Elite offensive (O) and defensive (D) players competed 1 vs. 1, while wearing an eye tracker that recorded their quiet eye (QE) and fixation and tracking (F-T) and an electrogoniometer that measured head angle. External cameras recorded skate duration during four skate phases: P1 preparation, P2 decision-making, P3 cut to boards, P4 contact. The QE was the final fixation prior to contact between O and D as they skated towards and across the WL during P3 and P4. Skate phase durations (%) did not differ by rink or rink by position. More QE and F-T occurred on the WL on the LUL rink than on the Control. The expected increase in head angle on the LUL rink did not occur during P3 or P4. Post-hoc results also showed O and D skated further from the boards on the LUL rink, suggesting the players preferred to control the puck on white ice, rather than the orange colour of the LUL rink. More research is needed to determine if these results apply to the competitive setting.

Quiet eye training facilitates visuomotor coordination in children with developmental coordination disorder

INTRODUCTION

Quiet eye training (QET) has been shown to be more effective than traditional training (TT) methods for teaching a throw and catch task to typically developing 8-10 yr old children. The current study aimed to apply the technique to children with developmental coordination disorder (DCD).

METHOD

30 children with DCD were randomly allocated into TT or QET intervention groups. The TT group were taught how to control their arm movements during the throw and catch phases, while the QET group were also taught to fixate a target location on the wall prior to the throw (quiet eye1; QE1), followed by tracking the ball prior to the catch (quiet eye2; QE2). Performance, gaze and motion analysis data were collected at pre/post-training and 6-week retention.

RESULTS

The QET group significantly increased QE durations from pre-training to delayed retention (QE1 = +247 ms, QE2 = +19%) whereas the TT group experienced a reduction (QE1 = -74 ms, QE2 = -4%). QET participants showed significant improvement in the quality of their catch attempts and increased elbow flexion at catch compared to the TT group (QET = -28°, TT = -1°).

CONCLUSION

QET changed DCD children's ability to focus on a target on the wall prior to the throw, followed by better anticipation and pursuit tracking on the ball, which in turn led to improved catching technique. QET may be an effective adjunct to traditional instructions, for therapists teaching visuomotor skills to children with DCD.

Quiet eye distinguishes children of high and low motor coordination abilities

PURPOSE

This is the first study to use the quiet eye (QE) as an objective measure of visuomotor control underpinning proficiency differences in children's motor coordination.

METHODS

Fifty-seven, year 5 primary school children (9-10 yr old) completed the Movement Assessment Battery for Children, Second Edition (MABC-2), while wearing a gaze registration system. Participants were subsequently divided into one of three ability groups: high motor coordination (HMC), median motor coordination (MMC), and low motor coordination (LMC) based on these MABC-2 scores (mean % rank: HMC = 84%, MMC = 51%, LMC = 19%). QE analyses were performed for the fourth task of the MABC-2, which involved throwing a tennis ball against a wall and catching it on the return.

RESULTS

The HMC group was more successful in the catching task than both other groups (catching percentage: HMC = 92%, MMC = 62%, LMC = 35%) and demonstrated superior visuomotor control throughout the throwing and catching phases of the task. Compared with the other groups, the HMC group demonstrated longer targeting QE fixations before the release of the ball (HMC = 500 ms, MMC = 410 ms, LMC = 260 ms) and longer tracking QE durations before catching (HMC = 260 ms, MMC = 200 ms, LMC = 150 ms). There were no significant differences in ball flight time between the groups. Mediation analyses revealed that only the duration of the tracking QE predicted group differences in catching ability.

CONCLUSIONS

Findings suggest that the ability to predict and calibrate movements based on sensory feedback may be impaired in children with movement coordination difficulties and have implications for how they are taught fundamental movement skills.

Performing Under Pressure: The Effects of Physiological Arousal, Cognitive Anxiety, and Gaze Control in Biathlon

The authors provide evidence that choking under pressure is associated with changes in visual attention. Ten elite biathlon shooters were tested under separate low-pressure (LP) and high-pressure (HP) conditions after exercising on a cycle ergometer at individually prescribed power output (PO) levels of 55%, 70%, 85%, and 100% of their maximum oxygen uptake. The authors determined difference scores by subtracting each athlete's score in the LP condition from his or her score in the HP condition for heart rate (d-HR), rate of perceived exertion (d-RPE), cognitive anxiety (d-CA), and cognitive worry (d-CW), and final fixation on the target or quiet eye gaze (d-QE). Using regression analysis, the authors determined predictors of accuracy for each HP PO level. At PO 55%, the authors found 3 predictors (d-HR, d-RPE, d-QE) that accounted for .62 of the adjusted R2 variance. Accuracy was higher when d-QE was lower and d-RPE and d-HR were higher than the values found in the LP condition. At PO 100%, however, an increase in d-QE and d-RPE accounted for .58 of the adjusted R2 variance. Accuracy was dependent on an increase in external focus (positive d-QE) independently of heart rate. At the highest PO level, directing visual attention externally to critical task information appeared to insulate the athletes from choking under HP.

Gaze behaviors of goaltenders under spatial–temporal constraints

It is still not known what underlies successful performance in goaltending. Some studies have reported that advanced cues from the shooter's body (hip, kicking leg or support leg) are most important (Savelsbergh, G. J. P., Williams, A. M., Van der Kamp, J., & Ward, P. (2002). Visual search, anticipation and expertise in soccer goalkeepers. Journal of Sports Sciences, 20, 279-287; Savelsbergh, G. J. P., Williams, A. M., Van der Kamp, J., & Ward, P. (2005). Anticipation and visual search behaviour in expert soccer goalkeepers. Ergonomics, 48, 1686-1697; Williams, A. M., & Burwitz, L. (1993). Advanced cue utilization in soccer. In T. Reilly, J. Clarys, & A. Stibbe (Eds.), Science and football II (pp. 239-243). London, England: E&FN Spon), while others have found that the early tracking of the object prior to and during flight is most critical (Bard, C., & Fleury, M. (1981). Considering eye movement as a predictor of attainment. In: I. M. Cockerill, & W. M. MacGillvary (Eds.), Vision and Sport (pp. 28-41). Cheltenham, England: Stanley Thornes (Publishers) Ltd.). These results are similar to those found in a number of interceptive timing studies (Land, M. F., & McLeod, P. (2000). From eye movements to actions: How batsmen hit the ball. Nature Neuroscience, 3, 1340-1345; Ripoll and Fleurance, 1988; Vickers, J. N., & Adolphe, R. M. (1997). Gaze behaviour during a ball tracking and aiming skill. International Journal of Sports Vision, 4, 18-27). The coupled gaze and motor behavior of elite goaltenders were determined while responding to wrist shots taken from 5 m and 10 m on ice. The results showed that the goalies faced shots that were significantly different in phase durations due to distance (5 versus 10 m), but this was not a factor in making saves. Instead, the ability to stop the puck was dependent on the location, onset and duration of the final fixation/tracking gaze (or quiet eye) prior to initiating the saving action. The relative onset of quiet eye was significantly (p<.001) earlier (8.6%) and the duration was longer on saves (M=80.5%; 952.3 ms) compared to goals (onset 18.86%; M=70.1%, 826.1 ms). The quiet eye was located on the puck/stick during the preparation and execution of the shot in 70.53% of all trials, or on the ice in front of the release point of the puck (25.68%) and rarely on the body of the shooter (2.1%). The results are discussed within the context of current research on goaltending with specific emphasis on the timing of critical cues and the effect of tasks constraints.

Gaze characteristics of elite and near-elite athletes in ice hockey defensive tactics

Traditional visual search experiments, where the researcher pre-selects video-based scenes for the participant to respond to, shows that elite players make more efficient decisions than non-elites, but disagree on how they temporally regulate their gaze. Using the vision-in-action [J.N. Vickers, J. Exp. Psychol.: Human Percept. Perform. 22 (1996) 342] approach, we tested whether the significant gaze that differentiates elite and non-elite athletes occurred either: early in the task and was of more rapid duration [A.M. Williams et al., Res. Quart. Exer. Sport 65 (1994) 127; A.M. Williams and K. Davids, Res. Quart. Exer. Sport 69 (1998) 111], or late in the task and was of longer duration [W. Helsen, J.M. Pauwels, A cognitive approach to visual search in sport, in: D. Brogan, K. Carr (Eds.), Visual Search, vol. II, Taylor and Francis, London, 1992], or whether a more complex gaze control strategy was used that consisted of both early and rapid fixations followed by a late fixation of long duration prior to the final execution. We tested this using a live defensive zone task in ice hockey. Results indicated that athletes temporally regulated their gaze using two different gaze control strategies. First, fixation/tracking (F/T) gaze early in the trial were significantly shorter than the final F/T and confirmed that the elite group fixated the tactical locations more rapidly than the non-elite on successful plays. And secondly, the final F/T prior to critical movement initiation (i.e. F/T-1) was significantly longer for both groups, averaging 30% of the final part of the phase and occurred as the athletes isolated a single object or location to end the play. The results imply that expertise in defensive tactics is defined by a cascade of F/T, which began with the athletes fixating or tracking specific locations for short durations at the beginning of the play, and concluded with a final gaze of long duration to a relatively stable target at the end. The results are discussed within the context of gaze research in open and closed skills, as well as theoretical models of long-term memory and decision making in sport.

Temporal judgments, hemispheric equivalence, and interhemispheric transfer in adolescents with attention deficit hyperactivity disorder

This study investigated temporal processing abilities, hemispheric asymmetry, interhemispheric transfer, and stimulant medication effects in adolescents with attention deficit hyperactivity disorder (ADHD). Pairs of light emitting diodes in a visual half-field display (i.e., bilateral and unilateral presentations) were presented to examine medication effects, temporal judgments, hemispheric asymmetry, and interhemispheric transfer in male adolescents with ADHD and matched controls on age and gender. Participants responded (YES/NO) whether pairs of spatially separated diodes were illuminated simultaneously. Stimulant medication did not have an affect on temporal judgments, hemispheric equivalence, or interhemispheric transfer. No group differences in temporal judgments in any of the paired conditions were revealed. Both the ADHD and control groups demonstrated hemispheric equivalence for temporal judgments. Unexpectedly, the ADHD group demonstrated significantly faster interhemispheric transfer times when compared to the control group. The overall findings indicate that the reported deficit in time perception among individuals with ADHD may be restricted to tasks that involve response inhibition, reaction time, and/or motor movements (e.g., replicate durations of stimuli by pressing a lever).

How far ahead do we look when required to step on specific locations in the travel path during locomotion?

Spatial-temporal gaze behaviour patterns were analysed as normal participants wearing a mobile eye tracker were required to step on 17 footprints, regularly or irregularly spaced over a 10-m distance, placed in their travel path. We examined the characteristics of two types of gaze fixation with respect to the participants' stepping patterns: footprint fixation; and travel fixation when the gaze is stable and travelling at the speed of whole body. The results showed that travel gaze fixation is a dominant gaze behaviour occupying over 50% of the travel time. It is hypothesised that this gaze behaviour would facilitate acquisition of environmental and self-motion information from the optic flow that is generated during locomotion: this in turn would guide movements of the lower limbs to the appropriate landing targets. When participants did fixate on the landing target they did so on average two steps ahead, about 800-1000 ms before the limb is placed on the target area. This would allow them sufficient time to successfully modify their gait patterns. None of the gaze behaviours was influenced by the placement (regularly versus irregularly spaced) of the footprints or repeated exposures to the travel path. Rather visual information acquired during each trial was used "de novo" to modulate gait patterns. This study provides a clear temporal link between gaze and stepping pattern and adds to our understanding of how vision is used to regulate locomotion.

Head, eye and arm coordination in table tennis

The aim of this study was to determine the role of head, eye and arm movements during the execution of a table tennis forehand stroke. Three-dimensional kinematic analysis of line-of-gaze, arm and ball was used to describe visual and motor behaviour. Skilled and less skilled participants returned the ball to cued right or left target areas under three levels of temporal constraint: pre-, early- and late-cue conditions. In the pre- and early-cue conditions, both high and low skill participants tracked the ball early in flight and kept gaze stable on a location in advance of the ball before ball-bat contact. Skilled participants demonstrated an earlier onset of ball tracking and recorded higher performance accuracy than less skilled counterparts. The manipulation of cue condition showed the limits of adaptation to maintain accuracy on the target. Participants were able to accommodate the constraints imposed by the early-cue condition by using a shorter quiet eye duration, earlier quiet eye offset and reduced arm velocity at contact. In the late-cue condition, modifications to gaze, head and arm movements were not sufficient to preserve accuracy. The findings highlight the functional coupling between perception and action during time-constrained, goal-directed actions.

Gaze pursuit and arm control of adolescent males diagnosed with attention deficit hyperactivity disorder (ADHD) and normal controls: evidence of a dissociation in processing visual information of short and long duration

Three-dimensional kinematic analysis of line of gaze, arm and ball was used to describe the visual and motor behaviour of male adolescents diagnosed with attention deficit hyperactivity disorder (ADHD). The ADHD participants were tested when both on (ADHD-On) and off (ADHD-Off) their medication and compared to age-matched normal controls in a modified table tennis task that required tracking the ball and hitting to cued right and left targets. Long-duration information was provided by a pre-cue, in which the target was illuminated approximately 2 s before the serve, and short-duration information by an early-cue illuminated about 350 ms after the serve, leaving approximately 500 ms to select the target and perform the action. The ADHD groups differed significantly from the control group in both the pre-cue and early-cue conditions in being less accurate, in having a later onset and duration of pursuit tracking, and a higher frequency of gaze on and off the ball. The use of medication significantly reduced the gaze frequency of the ADHD participants, but surprisingly this did not lead to an increase in pursuit tracking, suggesting a barrier was reached beyond which ball flight information could not be processed. The control and ADHD groups did not differ in arm movement onset, duration and velocity in the short-duration early-cue condition; in the long-duration pre-cue condition, however, the ADHD group's movement time onset and arm velocity differed significantly from controls. The results show that the ADHD groups were able to process short-duration information without experiencing adverse effects on their motor behaviour; however, long-duration information contributed to irregular movement control.

"Look where you're going!": gaze behaviour associated with maintaining and changing the direction of locomotion

In order to fully understand how vision is used to guide locomotion it is necessary to know what people look at as they move through the environment. This study provides information, hitherto lacking, regarding gaze behaviour associated with both maintaining and changing the direction of locomotion: activities that are essential for efficient navigation through our cluttered environment. Participants' spatiotemporal gaze patterns were recorded whilst they performed a task requiring that they either maintained a straight walking trajectory or changed their direction of walking by 30 degrees or 60 degrees, left or right, at the midpoint of a 9-m path. Participants were either visually cued to turn when they stepped on a trigger mat placed one step before the mid-point of the walkway (cued trials) or given verbal instruction about the required route prior to the start of each trial (advance knowledge trials). Our clear finding was that for the large majority of the time participants' gaze was aligned with environmental features lying in their current plane of progression both prior to and following the onset of the transition stride during which the direction change was implemented. This gaze behaviour was observed both during cued trials (78% of total fixation time prior to the transition stride onset and 89% following the transition stride onset) and advance knowledge trials (67% prior to transition stride onset, 92% following transition stride onset). When not aligned with the plane of progression, gaze was normally fixated on environmental features related to either known or potential future routes. Prior to changing the direction of walking, individuals invariably made saccadic eye movements in order to align gaze with the end-point of the required travel path. This gaze realignment was invariably accompanied by head reorientation, which was initiated, on average, at the same time as the saccade. On average, participants fixated gaze on their goal (represented by the cue light at the travel path end-point) until after head realignment with the new path was achieved. Additionally, the head was consistently aligned with participants' current walking direction prior to and following the transition stride even on the minority of occasions when they were looking elsewhere. These findings challenge the ecological validity of existing theories of how visual information is used to determine heading direction and are consistent with the proposal that aligning the head with the desired travel direction through coordinated eye and head movements provides the CNS with an allocentric frame of reference that is used to control the movement of the body in space.

Decision training: the effects of complex instruction, variable practice and reduced delayed feedback on the acquisition and transfer of a motor skill

Novice, intermediate and advanced baseball hitters followed a 7-week training programme, in which they received either behavioural training or decision training. Participants in the behavioural training group received simple-to-complex instruction, variable practice and an abundance of feedback throughout the acquisition period; the decision training group received complex instruction, variable practice and reduced delayed feedback. As predicted, the intermediate and advanced hitters who received decision training hit at a lower level (%) during acquisition but at a higher level during a transfer test in week 7. Novices in the behavioural training group were better than novices in the decision training group over both acquisition and transfer trials.

Where and when do we look as we approach and step over an obstacle in the travel path?

Spatio-temporal gaze behaviour patterns were analysed as normal participants wearing a mobile eye tracker approached and stepped over obstacles of varying height in the travel path. We examined the frequency and duration of three types of gaze fixation with respect to the participants' stepping patterns: obstacle fixation (ObsFix); travel fixation (TravFix) (when the gaze is stable and travelling at the speed of whole body) and fixation in the 4-6m region (Fix4-6). During the approach phase to the obstacle, participants fixated on the obstacle for approximately 20% of the travel time. Only Fix4-6 duration was modulated as a function of obstacle height by regulating the frequency and reflected the increased time needed for detection of the small low contrast obstacle in the travel path. Frequency of ObsFix increased significantly as a function of obstacle height and reflected visuo-motor transformation needed for limb elevation control. Participants did not fixate on the obstacle as they were stepping over, but did the planning in the steps before. TravFix duration and frequency was constant while Fix4-6 duration was higher in the step before and step over the obstacle reflecting visual search of the landing area for the lead limb following obstacle avoidance. These results clearly show that obstacle information provided by vision is used in a feed-forward rather than on-line control mode to regulate locomotion. Information about self-motion acquired from optic flow during TravFix can be used to control velocity of locomotion.

Visual control when aiming at a far target

Gaze behavior of elite basketball athletes was determined as they performed 10 accurate and 10 inaccurate free throws (FTs) to a regulation basket wearing an eye tracker that permitted normal accuracy. Experts (mean FT = 78%) differed significantly from near experts (mean FT = 56%) in having a longer fixation on the target combined with an earlier fixation offset during the shooting action. These results, which depart from current models of near aiming, are tentatively explained using a location-suppression hypothesis. During the early phases of the aiming action, a fixation of long duration is needed on a specific target location. As the aiming action is then performed, vision appears to be a liability and is suppressed.

Visual control when aiming at a far target

Gaze behavior of elite basketball athletes was determined as they performed 10 accurate and 10 inaccurate free throws (FTs) to a regulation basket wearing an eye tracker that permitted normal accuracy. Experts (mean FT = 78%) differed significantly from near experts (mean FT = 56%) in having a longer fixation on the target combined with an earlier fixation offset during the shooting action. These results, which depart from current models of near aiming, are tentatively explained using a location-suppression hypothesis. During the early phases of the aiming action, a fixation of long duration is needed on a specific target location. As the aiming action is then performed, vision appears to be a liability and is suppressed.

Gaze control in putting

The gaze of low and higher handicap golfers was assessed while they performed consecutive putts from 3 m, wearing an eye-movement helmet that permitted normal mobility. MANOVA (count and duration), with univariate follow-up, revealed significant differences in gaze between five low (LH, 0-8) and seven higher handicap golfers (HH, 10-16). The LH (ie more highly skilled) golfers were found to use a variable form of gaze control in which longer fixation durations on the ball and target were observed, and there were fewer fixations on the club and surface, with more express saccades and quicker saccades between gaze locations. The HH golfers, in contrast, allocated the same mean durations to each gaze (about 1 s), independent of type of control (fixation, saccade, or tracking) or location (ball, club, target, or surface). In comparing hits to misses, there was an increased probability of hits if the golfers used express saccades to the club during preparation, and a steady fixation on the ball during the backswing/foreswing of the club, as well as a steady fixation on the surface during contact. These results suggest that with the acquisition of the putting skill, there are changes in gaze control, characterized by economy in the number of gaze shifts, the development of priority to specific gaze locations, and economy in the allocation of time between preferred gaze locations. In the discussion two reasons are proposed that may partially explain the results found here, as well as help further our understanding of the role of gaze in targetting skills.