Your Brain Sees More Than it Cares to Share

Image from Andreas Vesalius' 1543 De Humani Corporis Fabrica. Corbis

You're familiar with the mind-body problem. There's the meaty brain inside our skulls and then there's the conundrum of consciousness we experience every day. And the more we study the physical brain, the more we realize how much goes on beneath the surface of human cognition, like teaming depths beneath the surface of an ocean.

Now, a new study from University of Arizona doctoral degree candidate Jay Sanguinetti published in the journal Psychological Science casts another log on the fire.

(Image credit Jay Sanguinetti)

Just glance at the abstract image to your right. What do you see? Chances are you only noticed the abstract dark center of the image and not the white sea horse shapes on the sides.

Or did your brain recognize the sea horses and simply decide not to tell you?

That's the mind-bending conclusion in Sanguinetti's study. He flashed test subjects with a series of black silhouettes. They only looked at them for 170 milliseconds. Some of these images contained only abstractions but others also featured recognizable, real-world objects in white.

The researchers analyzed the subject's brainwaves and discovered that even if the person never consciously recognized the real-world shapes on the edges, their brains still identified them and processed their meaning. Specifically, they noted the N400 waveform in the subjects' EEG scans -- the tell-tale signature of a brain processing an image's meaning 400 nanoseconds after your see it.

So, in effect, your brain shares information with you on a need-to-know basis. It has to keep us on task in a world full of meaningless distractions and potential threats. That, after all, is what it evolved to do.

About the Author: Robert Lamb spent his childhood reading books and staring into the woods — first in Newfoundland, Canada and then in rural Tennessee. There was also a long stretch in which he was terrified of alien abduction. He earned a degree in creative writing. He taught high school and then attended journalism school. He wrote for the smallest of small-town newspapers before finally becoming a full-time science writer and podcaster. He’s currently a senior writer at HowStuffWorks and has co-hosted the science podcast Stuff to Blow Your Mind since its inception in 2010. In his spare time, he enjoys traveling with his wife Bonnie, discussing dinosaurs with his son Bastian and crafting the occasional work of fiction.