quiet eye Flashcards
(32 cards)
gaze rests on target before motor act initiated
visual information guides action - form of top-down attentional ctrl
gaze action system (Land 2009)
schema ctrl-specifies the current task and plans the overall sequence of actions
gaze system-responsible for locating and fixating task-relevant objects
visual system-supplies visual information to gaze and motor systems
motor system-coordinates limbs to carry out the task
visually guided actions are
task specific (goal directed) eye mvts that support planning and ctrl of manual action and are present throughout action sequences for more complex tasks- top down instructions dominate gaze behaviour in the performance of visually guided actions
Quiet eye (Vickers 2007)
The final fixation directed to a single location or object in the visuomotor workspace within 3 degrees of visual angle for at least 100 ms- basically last fixation to a target before moving
QE onset and offset
- onset occurs before final mvt in the motor task
- offset occurs when the fixation or tracking deviates off the target by more than 3 degrees of visual angle for more than 100 ms
Reasons why QE helps performance according to bicker
Your brain, which ctrls your limbs, gets information about what to do from your eyes and while performing a visually guided motor task a neural network is informed by our gaze and is organised only briefly so window of optimal organisation opens up (brain not actually like this)
elite tennis players
follow ball longer than other players and at impact their head and eyes are turned in the direction of the hitting zone (target)- keep eyes on ball up to moment of impact and after impact their head remains still and in direction of contact zone
processes undermining QE
QE reflects the organisation of visual attention ctrl parameters of the mvt- longer QE improves performance by permitting us to extend the duration of motor planning required for accurate aiming mvts - longer and earlier QE periods associated with expertise and accuracy
Quiet Eye Period
final fixation to a target before initiation of mvt - time acquisition of information for optimal coupling btw gaze and aiming mvt (ex: start of backswing in golf, first step in volleyball serve return, arm flexion in throwing, tiger pull in shooting)
4 types of task
- abstract task (golf putting: hole & ball)
- single fixated target (basketball shooting)
- interceptive timing (goalkeeper, serve)
- tactical (when to pass)
3 key aspects of putt
1) focus on ball prior to initiation of stroke
2) focus on ball during stroke
3) dwell (300ms) on ‘ball location’ just after stroke
vickers 1992
vickers 1992 putting
low handicap players made fewer and shorter gazes - greater economy ?
low handicap players also fixated ball longer in preparation and swing phases, ball fixated on more putts and hits in low handicap players- quiet eye linked to better performance
grand mean of QE duration in high and low handicap players (btw lots of studies)
low - 2317 ms
high- 1597 ms
from review of vickers 2012
QEP duration greater
in skilled than less skilled players
for successful than unsuccessful shots
in hard than easy shots
Penalty shooting - visual attention
keeper independent strategies most successful - target directed gaze important
football penalty shots to target (wood & Wilson 2010)
less accurate and successful when goalie moves arms (distraction), his mvt captures gaze of kicker and when kicker is under pressure to win - QE trained better accuracy
single target basket ball shooting (Vickers 1996)
longer QE in experts than non experts- longer final fixation on target (hoop/backboard) prior to initiation of final mvt (extension of arm toward target)
Wilson et al 2009 basket ball shooting task
findings in ctrl condition replicate influence of QE in accuracy of performance - longer and earlier onset of QE on hits compared to missed shots ( also later and shorter QE under threat)
ctrl modes (Panchuk 2006)
- predictive ctrl: actions are fully planned prior to their execution, based on early perceptually acquired information about ‘initial conditions’
- prospective ctrl: mvts are continuously updated to the point of interception
Ice hockey goalies (panckuk & Vickers 2006)
- location of quiet eye: 70% puck/stick and 25% on ice in front of release point
- earlier onset and longer QE saves goals
evidence for goaltenders using predictive ctrl mode Panchuk and vickers 2009
- early vision of puck and stick led to more saves
- an early and sustained QE on the puck
- poorer performance as more of shooter’s actions occluded
- slower RT when all but puck flight occluded
- 77% of glove saves using only single mvt
Vickers 2006 tactical speed skaters
speed skaters faster when they fixated on the tangent point (bend in ice) compared to other locations
Martell & vickers 2004 ice hockey defence and gaze
study showed that early in play, elite players used sorter duration fixations to specific locations than near elite players but later in play elites exhibited longer final gaze (QEP) to a relatively stable target - elite defensive team tactics was dependent on the use of 2 gaze behaviours that occurred in temporal sequence
longer QEP for
more complex and difficult shots (billiards)