Many people believe several images flashed before their eyes in only a fraction of a section would go unregistered by their brain; new research shows the brain can actually process an entire picture in only 13 milliseconds.
Past studies have suggested the brain would need 100 milliseconds. Researchers made these conclusions by asking participants to identify certain images such as "picnic" in a series of six to 12 images presented in a timeframe between 13 and 80 milliseconds, a Massachusetts Institute of Technology news release reported.
"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," Mary Potter, an MIT professor of brain and cognitive sciences and senior author of the study, said in the news release.
This "rapid-fire processing" could help direct the eyes to what they need to be looking at.
"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.
Visual information flows through the retina and into the brain which processes information such as "shape, color, and orientation."
The research team gradually increased the speed at which they showed the participants the images. They found that although the subjects' accuracy declined as the images sped up, it was still higher than chance at 13 milliseconds (which was the fastest the monitor could go).
"This didn't really fit with the scientific literature we were familiar with, or with some common assumptions my colleagues and I have had for what you can see," Potter said.
The study suggests "feedforward processing", which is the "flow of information in only one direction, from retina through visual processing centers in the brain," is all the brain needs identify concepts, as opposed to additional feedback processing. It also suggests the brain continues to process the information well after the image has disappeared.
"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.
