As most athletes know, good situational awareness is critical for making game-winning decisions under pressure. In this first part of a two-part blog, we’ll explore why our preconceptions of vision can be illusory, and why that matters when it comes to performing on the field.
Believing is Seeing
A large part of the brain is devoted to the primary sense of vision, which is often tested to the max under the demands of sports like football, hockey, basketball, and soccer. At a fundamental level, processing sports scenes involves two visual demands for the brain: identifying objects (knowledge dependent), and identifying motion (position, speed, and trajectory).
Perceiving objects is more challenging than we take for granted. This is because of the surprising fact that we have a very limited amount of detailed vision that we actually receive through the eyes. 20/20 vision is only provided by the fovea – a tiny part of the eye devoted to perceiving detail. While humans have a horizontal field of view of 210 degrees, only the central 3 degrees of that field actually yields detailed vision. Outside this focal point, the rest of our field of sight is pretty much blurry. By jumping this detailed spot around, the visual centers of the brain can construct a general sense of detailed awareness from key snapshots of the most important points in our view.
The visual sense that our view is rich with details is purely a facet of conscious perception, even though this notion seems counter-intuitive to our subjective experience. This is because the brain is extremely good at extrapolating a few key pieces of visual information to build a model of the world around us that is good enough for us to function. It’s a little like figuring out what a jigsaw will look like when only 10% of the pieces are in place, but those pieces give us the best big clues for the overall picture. In this sense, ‘believing is seeing’.
Blinded By Sight
There are a couple of catches though. The first is that constructing such models of the external visual world taxes the brain with a substantial workload of perceptual-cognitive processing. We’re effectively predicting and building the world around us as we see it, chunk by chunk.
The second catch is that to do this efficiently, precise visual scanning is needed. This is because these perceptual models are typically built on very short timescales, and so pertinent points of focus must be scanned extremely rapidly (especially true for sports). To achieve this, the eyeballs have to scan scenes by darting from point to point, a form of rapid target switching known as saccades. The problem is that when the eyes dart around, vision becomes so blurred that it becomes devoid of useful information. For this reason, the visual centers of the brain temporarily shut down to save on mental resources.
According to some estimates, our brains are actually blind for up to 15% of the time our eyes are open. We aren’t aware of this because saccades are discounted from conscious awareness. That said, by very quickly glancing from far left to far right, it is possible to perceive a brief blank flash – your visual brain turning off for a brief moment.
What It Means for Sports Vision
When it comes to sports vision, it’s critical to understand that a) most of what we see is blurred, and b) that darting our focus point around results in moments of blindness. With this in mind, we can see why visual search strategy is incredibly important when it comes to situational awareness in sports. It should come as no surprise that sports science research shows elite athletes have superior search strategies when compared to amateur athletes. When it comes to the chaotic and rapidly changes scenes of team sports, looking in the right place at the right time is paramount.
How the Pros See
Specifically, research has found that experts across a range of sports not only search more accurately but use fewer searches of the most informative points on display, combined with longer fixations. Contrastingly, novices are less informed, even though they scan more points.
Effective visual search techniques utilize experiential knowledge to enable the player to decide information priorities in order to selectively update detail in real-time. The crucial point here is that when fixating on a point for longer, the eyes are still, and the peripheral field of view can now be processed. In this sense, top athletes can narrow in on detail, hold their gaze, and simultaneously pay attention to what’s happening in the periphery. This is a sublime perceptual-cognitive skill that gives them an almost sixth sense of awareness.
In the follow-up to this blog, we will explore why peripheral vision is key for situational awareness, and take a look at methods to train this skill. In the meantime, if you want to learn more about vision from an ophthalmology perspective, then here is an up-to-date glossary of terms you can reference.
Until then, if you are interested in exploring more about the role of vision and awareness, check out this recent Expert’s Corner blog.
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