Computers Get Help from the Human Brain - Technology Review: Sajda's device, called C3Vision (cortically coupled computer vision), uses an electroencephalogram (EEG) cap to monitor brain activity as the person wearing it is shown about 10 images per second. Machine-learning algorithms trained to detect the neurological signals that signify interest in an image are used to analyze this brain activity. By monitoring these signals, the system rapidly ranks the images in terms of how interesting they appear to the viewer. The search is then refined by retrieving other images that are similar to those with the highest rank. "It's a search tool that allows you to find images that are very similar to those that have grabbed your attention," says Sajda.
At the speed at which it works, the conscious brain is unable to register a "hit." But the neurological visual pathways work much faster, says Sajda. The brain produces distinct electrical signals that can be detected and decoded by the 64 EEG electrodes within the cap. "It's on the edge of the subconscious," he says.