We’ve all been in the position where we’re trying to describe the location of something to our friends. We point, describe what we see and are incredulous when someone else can’t grasp it! As it turns out, there are limits to human vision and individuals don’t necessarily perceive objects in the same way. Researchers at UC Berkeley's Whitney Laboratory for Perception and Action, have released a study that may provide clues on how individuals uniquely assess distance and location.
Think about how often you employ your vision to make decisions. In the morning you may need to pour a cup of tea into your mug, a mistake could lead to a slippery mess! Maybe you drive to work—in your vehicle you must make a series of adjustments and movements on the road based on your visual perceptions.
You can also think about localization in terms of how we judge sports and make rules for competitions.
“Line judges need to rule on whether the ball is outside or inside the parameters. Even an error as small as half a degree of visual angle, equal to a sub-millimeter shift on the judge's retina, may influence the result of the whole match,” said Zixuan Wang, lead author of the study.
Several experiments were conducted to test participants visual localization, acuity and size perception. In one test the subjects were asked to identify the location of a circular target on a computer screen. In another, they were presented with two lines and were told to identify if one line was clockwise or counterclockwise to the other. In their final challenge, when shown a collection of arcs, they had to estimate the lengths of each.
Sound simple enough? Remarkably, the results varied drastically in the group and even within an individual’s personal line of sight.
Using the data, the Berkeley researchers were able to map the participants’ answers and ultimately show how everyone has their own “perceptual distortions.”
"We assume our perception is a perfect reflection of the physical world around us, but this study shows that each of us has a unique visual fingerprint," said Wang.
But what does that mean for our day to day lives? While we can conclude individuals have variant perception errors, the researchers also provided an explanation for why most of us can carry on with no drastic implications. For every perception error, we’ve learned how to adapt and compensate.
"Though our study might suggest that the source of our visual deficiencies can originate from our brain, further investigations are needed to uncover the neural basis,” said Wang. “What's also important is how we adapt to them and compensate for our errors.”
Next time you’re pointing out a landmark to a friend, remember your perceived reality could be a little different from theirs. To be on the safe side, try describing colours or other certain factors. Distance and location just might be variable!
Do you have any concerns about your eyesight? Reach out to your optometrist today at an FYidoctors clinic near you.