New research has clocked the human brain as being able to process entire images flashed before the eyes in as little as 13 milliseconds. The evidence is the first of such rapid processing speed and faster than the processing speed the brain is capable of suggested by other studies.

For the study, which was conducted by researchers at Massachusetts Institute of Technology, research participants were asked to look for a particular type of image, such as picnic or a smiling couple, as they were shown a rapid series of images. Study subjects were shown a series of either six or 12 images, each presented for between 13 milliseconds and 80 milliseconds.

Even when an image was shown for as little as 13 milliseconds, the subjects were able to process it, the researchers learned.

"The fact that you can do that at these high speeds indicates to us that what vision does is find concepts. That's what the brain is doing all day long - trying to understand what we're looking at," said senior study author Mary Potter, an MIT professor of brain and cognitive sciences.

"The job of the eyes is not only to get the information into the brain, but to allow the brain to think about it rapidly enough to know what you should look at next. So in general we're calibrating our eyes so they move around just as often as possible consistent with understanding what we're seeing," Potter said.

As Potter and her colleagues were conducting the research, they gradually increased the speed at which participants were shown the images until the subjects' answers were no better than if they were just guessing.

The team expected to see a dramatic decline in test performance around the 50 millisecond mark because of prior research that suggested that it took at least that long for the brain to process an image.

While performance did decline overall as the time subjects were shown images decreased from 50 milliseconds, subjects continued to perform better than chance on the tests until they were shown images for as little as 13 milliseconds, which was the fastest speed the computer monitor being used for the study could show an image.

The researchers suggest that even when presented for as little as 13 milliseconds, the human brain is capable of processing and storing that information for later recall.

"If images were wiped out after 13 milliseconds, people would never be able to respond positively after the sequence. There has to be something in the brain that has maintained that information at least that long," Potter said.

Potter and her colleagues' work appears in the journal Attention, Perception, and Psychophysics.