Our visual system fools us into thinking that we are looking at all moving objects simultaneously, but in fact we are looking at them one by one by one, a new research has found.
Although our eyes record the word as millions of pixels, "the visual system is fantastic at giving us a world that looks like objects, not pixels," says Northwestern University psychologist Steven L. Franconeri. It does this by grouping areas of the world with similar characteristics, such as color, shape, or motion.
The process is so seamless that we feel we're taking it all in simultaneously. But this, says a new study by Franconeri and his colleague Brian R. Levinthal, is "an illusion."
Instead, they say, that for some types of grouping, the visual system is limited by its ability to perceive only one group at a time.
To demonstrate this point, the authors performed two experiments, simplifying the "car pieces" into pairs of moving dots. In the first experiment, participants had to find the pairs that were vertically arranged among pairs that were horizontally arranged.
In the second, instead of finding a group with a specific shape, they were asked to find a group among non-groups-like whole cars among scattered pieces.
In both tasks, "people were surprisingly slow," says Franconeri. As participants were asked to make decisions involving more groups, they took more and more time.
They were limited by their one-at-a-time visual systems, which, he says, "needed to flip through the groups, at a rate of about 10 per second."
"The visual system fools us into thinking that we process everything in rich detail, when in many cases we are processing only the most relevant pieces of the world," says Franconeri.
The study was recently published in Psychological Science, a journal of the Association for Psychological Science.