From Bench to Bunker: There is ground being broken in the field of visual recognition. It turns out that your brain registers information about an image long, long before you’re cognizant of it. And this mental reaction can be detected and measured.
In the following experiment, subjects are being shown satellite images of the desert at incredibly fast rates and are looking for man-made structures which might indicate a town or encampment.
The images flash at a rate of 20 per second, so fast that before he can truly perceive the details of each landscape, it is gone. He pushes no buttons, takes no notes. His performance is near perfect.
[…] The computer has learned what the man’s brain activity looks like when he sees one of the visual targets, and, based on that information, it quickly reshuffles the images. When the man sorts back through the hundreds of images—most without structures, but some with—almost all the ones with buildings in them pop to the front of the pack. His brain and the computer have done good work.
I have heard of this being done in the past with recall of past images. When you see something you’ve seen before, your brain reacts in a specific way. So, a murder suspect being shown crime scene photos – which only the police and the actual murderer have seen – may react in a way that can be detected and used in court.