What do you think of this fact?
You glance at a clock with a ticking second hand, and for a moment it seems stuck. The first second drags on noticeably longer than the ones after it. Did the clock hesitate? No. Your brain did.
The stopped clock illusion
The effect has a name: chronostasis. In 2001, a team led by Kielan Yarrow at the Institute of Neurology in London described it in the journal Nature. The paper says that when people make a quick eye movement toward a silently ticking clock, the second hand can seem to take longer than normal to move.
HealthDay described how the experiment worked. Volunteers stared at a cross on one side of a screen, then moved their eyes to a digital seconds counter on the other side. The counter showed a “1” for a random 0.5 to 1.5 seconds and then counted on normally. Participants had to say whether that first interval felt longer than the rest. And the longer the eye movement, the stronger the illusion became.
Your brain edits the tape
The explanation is surprisingly neat. During a quick eye movement, called a saccade, you see very little. Psychologist Bruce Bridgeman told HealthDay that vision is essentially absent for about a 20th of a second during one. Instead of showing you a blurry gap, your brain fills it in: it acts as if what you see after your eyes land had been there all along.
That backdating is what stretches the first second. In the Nature paper, the authors propose that the brain extends the perception of the new target backwards in time to just before the eye movement. The longer the movement, the longer the clock seems to stand still.
According to the researchers, this happens with every single eye movement. You only notice it when something like a ticking clock gives you a point of comparison.
Bonus fact: According to HealthDay, you move your eyes about three times a second, so your brain is patching up your view of the world all day long.
Time doesn’t stop when you look at the clock. Your brain just rewinds a little.