Our Brain Sees Things We Don’t, Scientists Say

Lisa Franchi November 15, 2013

Our brain actually understands visual input that we may never consciously perceive. That’s the finding of a new study published in the journal Psychological Science.

Jay Sanguinetti of the University of Arizona and his team asked volunteersto view a series of black silhouettes, some of which contained meaningful, real-world objects hidden in the white spaces on the outsides. As the participants perform the task, they looked at their brain activities using the electroencephalogram machine or EEG.

"We were asking the question of whether the brain was processing the meaning of the objects that are on the outside of these silhouettes," Sanguinetti said. "The specific question was, ’Does the brain process those hidden shapes to the level of meaning, even when the subject doesn’t consciously see them?" said Sanguinetti. Their findings indicate yes.

Brain scans revealed that even though a person never consciously recognised the shapes on the outside of the image, their brains still processed such visual information to the level of understanding their meaning. According to Sanguinetti, the brain’s signature for meaningful processing indicates that it that has recognized an object and associated it with a particular meaning.

"It happens about 400 milliseconds after the image is shown, less than a half a second," said Mary Peterson, Sanguinetti’s research adviser and a professor of psychology and director of the UA’s Cognitive Science Programme."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."

Furthermore, the N400 waveform does not appear on the EEG of the subjects as they look at truly novel silhouettes without images of any real-world objects. This, according to the researchers, indicates that the brain does not recognise meaningful object in the image.

Research breakthrough

"We have neural evidence that the brain is processing the shape and its meaning of the hidden images in the silhouettes we showed to participants in our study."said Peterson. But this finding leads to a more important question – why would the brain process the meaning of a shape when a person is ultimately not going to perceive it?

"Many, many theorists assume that because it takes a lot of energy for brain processing, that the brain is only going to spend time processing what you’re ultimately going to perceive," added Peterson. "But in fact the brain is deciding what you’re going to perceive, and it’s processing all of the information and then it’s determining what’s the best interpretation."

In future studies,Peterson and Sanguinetti plan to look for the specific regions in the brain where the processing of meaning occurs.

Source of this article:

Your brain sees things you don’t