You’re waiting in an unbearably long line. You tap your feet and check you watch - over and over again. Your body posture and movement convey your restlessness to all nearby observers. But are your eye movements giving away your impatience as well?
Saccades, which are the eye movements we make when we change our visual attention from one object to another, have been found to correspond with our relation to time. Sound strange? Consciously or not, this is true of how we move other parts of our body as well — tapping our feet, for example.
Reza Shadmehr, professor of biomedical engineering and neuroscience at Johns Hopkins University, took what we know about waiting and these types of body movements and applied it to the eyes. In his study, he asked subjects to focus on every new dot that appeared on a screen and measured how quickly the subjects were able to change their focus to the next dot. He discovered that some subjects transitioned focus very rapidly, whereas other subjects were significantly slower (as much as 50 percent slower) in changing where they were looking.
Subjects were then asked to pause before focusing on the next dot when it appeared. If they did not pause for a long enough duration, they were given a penalty. Subjects were not told exactly how long they needed to pause before they could focus on the next dot.
As you may have guessed, natural curiosity meant that some people focused on the new dot almost as soon as it appeared, but others were a bit more patient. For those who were willing to wait longer, Shadmehr’s team increased the amount of time required to wait, and decreased the amount of required waiting time for the subjects who were less willing to wait. By doing this, they could determine exactly how long people were willing to wait while still trying to avoid the penalty.
So how do these two exercises relate? Shadmehr examined how fast the participants moved their eyes in general and then at how long they were willing to wait before focusing on the next dot. The result? There was a strong correlation between the two, meaning that those of us who have quicker eye movements are more likely to be less patient, and those with slower eye movements are probably more patient. This correlation may be the result of how our nervous system controls how we move, as we are motivated to move when we feel we are suffering negative consequences or missing out on new opportunities by not doing so.
These findings are especially important when viewed in combination with a 2012 study that found that Attention Deficit Hyperactivity Disorder (ADHD), Fetal Alcohol Spectrum Disorder and Parkinson’s Disease can be easily identified by studying the eye movements of subjects watching television.
Eye movements in those with diseases differ in certain characteristics when compared to those of control subjects. The costs of medical tests are continuing to rise, and eye-tracking tests are a significantly cheaper and less labor-intensive method of diagnosis. Shadmehr and others have proven that we can learn a great deal from not only where we look but how quickly we look there.
