The Sixth Sense; Brain Sees things that You Don't

University of Arizona researchers have found that sometimes brain processes visual information that you may never consciously perceive. The study challenges theories about how the brain works.

Each day, we get bombarded with a huge amount of visual data. The brain does a marvelous job of sifting through all the junk to give us the best-possible interpretation of what's happening in the world.

The study was conducted by Jay Sanguinetti, a doctoral degree candidate at the University and his colleagues. The team wanted to know if the brain deciphers hidden images in the visual field. They found that it does, but chooses not to tell us about it.

For the study, researchers showed participants a series of black silhouettes. Some of these silhouettes had meaningful objects hidden in white spaces. The participants were hooked to a brain scanner while they looked at the images. Study results showed that the brain showed signs of object recognition even when the person wasn't able to perceive the image.

"There's a brain signature for meaningful processing," Sanguinetti said. A peak in the averaged brainwaves called N400 indicates that the brain has recognized an object and associated it with a particular meaning."

"As one looks at brainwaves, they're undulating above a baseline axis and below that axis. The negative ones below the axis are called N and positive ones above the axis are called P, so N400 means it's a negative waveform that happens approximately 400 milliseconds after the image is shown," he added, according to a news release.

The brain scans of participants had N400 peak, indicating that the brains had understood the meaning of the shape.

The study also shows that the brain sifts through data to give the person the best possible interpretation of the scene.

Their research is published in the journal Psychological Science.