Sunday, May 1, 2011

Understanding the “Quiet Eye” in Athletic Performance.


“Vision without action is a dream. Action without vision is simply passing the time. Action with Vision is making a positive difference.”  ~Joel Barker

“We are limited, not by our abilities, but by our vision.” ~ Anonymous

The brain is a powerful computational engine, capable of some amazing feats, but the information it puts out is only as good as the information it takes in. Thus, one of the major differences that sports scientists have found between experts and novices is how they orient their attention to take in information. Several dominant theories of attention emphasize the role of “unconscious” or implicit processing. Master’s (1992) conscious processing hypothesis, Wulf’s (2007) constrained action hypothesis, and Singer’s (2000) five-step strategy all suggest that focusing on one’s own body (or the mechanics of one’s actions) disrupts motor performance and therefore recommend that attention be directed externally, to the effect/goal one is trying to achieve, in order to optimize performance. Both Singer and Wulf specifically recommend attending to the goal of the action during performance and during learning (see Singer, 2000, 2002; Wulf 2007 for reviews). All of these theories of attention deal with mental attention or what we might colloquially call concentration (i.e., thinking about the goal versus thinking about my body) but do specify the role of visual attention (i.e., looking at the goal versus looking at my positioning).  

Other areas of sport psychology research however, deal with visual attention specifically. Using sophisticate gaze tracking technology, researchers have shown that in experts, gaze is directed to the most relevant targets/objects in the visual field and that gaze is relatively stable, in novices however gaze is much more erratic (e.g., Vickers, 2007; Williams & Ford, 2008). This finding has been referred to as the quiet eye phenomenon.  Quiet eye specifically refers to duration of fixation on a task-relevant target prior to the execution of movement. Multiple studies have continuously shown the quite eye to be a reliable and valid measure of optimal control of visual attention.

In a seminal study of golf putting, Vickers (1992) found that gaze differences mediated performance. That is, differences in the scanning path during the alignment phase of the putt and timing and orientation differences during the putt itself, predicted the success of the putt. More skilled golfers, with better accuracy, maintained a steady final focus (quiet eye) on the center of the back of the ball for approximately 2s. Less skilled golfers, who had worse accuracy, did not maintain fixation as long (1.2-1.5s) and had a more erratic gaze orientation.

In a later study, Wilson and Pearcey (2009) assessed the gaze behavior of golfers in both the preparation (line reading) and execution (ball striking) of different putts. Six golfers completed 25 3-m putts on five different slopes (flat, 0.9° and 1.8° left-to-right, 0.9° and 1.8° right-to-left), and eye-tracking hardware/software was used track the motion of the golfers’ eyes with high fidelity. In general, steeper break angles (1.8°) resulted in worse performance, and length of the quiet eye period (the duration of gaze fixation prior to putter movement predicted accuracy.  That is, when golfers had longer, more stable fixation times prior to putter movement, they were more likely to be accurate.

Anxiety and Gaze Control
Vickers and Williams (2007) found evidence that choking under pressure resulted in shifts in visual attention (with choking being associated with more erratic eye movement). Ten elite biathlon shooters were tested under separate low-pressure and high-pressure conditions after exercising on a cycle ergometer at 55%, 70%, 85%, and 100% of their maximum oxygen uptake. At lower levels of stress (55% of max), the authors found that accuracy was higher when the differences in eye fixation were smaller between high pressure and low pressure conditions, but only when heart rate and perceived exertion (RPE) were higher than during the low pressure condition.  At higher levels of stress (100% of max) however, accuracy was related to quiet eye (i.e., improved gaze control) independent of heart rate or RPE. Thus, the authors conclude, at the higher levels of stress and fatigue, directing visual attention externally to critical task information appears to protect against the catastrophic effects of choking under pressure.

Recently, Vine and Wilson (2010) studied the efficacy of quiet eye training in improving learning and performance under pressure for novices in a putting task. Subjects performed 320 putts during a training phase in which they received either quiet eye training or standard technical training. During quiet eye training, subjects received similar verbal instructions as during standard training (e.g., “Stand with legs hip width apart and keep your head still.”) but in such a way as to emphasize gaze control and maintaining the quiet eye (e.g. “Assume a stance to ensure that gaze is on the back of the ball”). After training, subjects completed an additional 120 putts during a testing phase that consisted of a retention test, followed by a high-pressure transfer test, and finishing with a low-pressure retention test. The quiet eye trained group maintained more effective attentional control and performed significantly better in the pressure test compared to the control group. Even outside of the high-pressure test,  longer quiet eye periods predicted better performance, suggesting a generally beneficial effect of a long, calm final fixation and that this fixation period is especially vulnerable to anxiety from the increased pressure to perform. Thus, although the specific details that underlie the quiet eye phenomenon remain to be illuminated, at least one lesson seems clear: When you do feel anxious, try to control your visual attention, stay visually focused on your target and keep your gaze steady.

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