When babies are just three to four months old, they can pick out image differences that adults never notice. But after the age of five months, the infants lose their super-sight abilities, reports Susana Martinez-Conde for Scientific American.
Don’t get too jealous of the superior discrimination that infants have however: The reason adults—or even babies older than about eight months—don’t have it is because over time, our brains learn what differences are important to notice.
For example, when adults look at the images of a snail (below) they typically say that glossy snail A and and glossy snail B are the most similar. The matte-looking snail C seems to be the outlier. But a baby can tell that snail B and snail C are actually more similar. Though it is hard for adults to see, snail A stands out from the others—the surface of the snail reflects very different lighting conditions. Babies are more sensitive to that seemingly trivial image difference.
“[W]e learn to ignore certain types of differences so that we can recognize the same object as unchanging in many varied scenarios,” writes Martinez-Conde.