Washington: Rapidly changing images may look like a blur to infants as their eyes take 10 times longer than adults to process movement, a new study had found.

Researchers at the University of California, Davis, found that while infants can perceive flicker or movement, they may not be able to identify the individual elements within a moving or changing scene as well as an adult.

"Their visual experience of changes around them is definitely different from that of an adult," study researcher Faraz Farzin was quoted as saying by a website.

Babies' brains gradually develop the ability to use visual information to discover and process their world, the researchers said.

They found that the speed limit at which babies can recognise individual moment-to-moment changes is about half a second -- about 10 times slower than adults, who can recognise rapid, individual changes that occur 50 to 70 milliseconds or slower.

To determine the speed limit on infants' visual perception, the researchers monitored the eye movements of a group of 6- to 15-month-olds as they were shown four flickering squares.

Three squares flickered from black to white and back, and one square flickered white to black, which was intended to draw more attention because it is out of phase with the other squares — the "odd man out."

Tracking the infants' eye movements showed that they did not spend more time looking at the odd white-to-black square, suggesting they could not distinguish it as being different, the researchers reported in the journal Psychological Science. "It was surprising how coarse their resolution was." Farzin said.

Specifically, the researchers found the six- and nine-month-olds could differentiate the alternating squares up to a rate of just 0.5 hertz, or one flicker per two seconds; the limit for the 15-month-olds was one hertz, or two flickers per two seconds -- which is eight times coarser than the resolution observed in adults who participated in the same flicker experiment.

The research suggests that for infants younger than 15 months, a TV show or movie in which scenes change faster than two frames per second most likely look like a blur.

For example, 24 frames per second are about the rate at which movies are filmed — way too fast for babies to decipher.