Sanguinetti presented black silhouettes to his subjects and in the white space of some of the images, he hid common objects. The subjects didn't notice but their brains did. About 400 milliseconds after the picture displayed, the "N400" negative wave peaked when there was a meaningful object hidden in the picture.
Your intuition isn't always right but it has a bigger database to work with than the official memory.
"A doctoral candidate in the UA's Department of Psychology in the College of Science, Sanguinetti showed study participants a series of black silhouettes, some of which contained meaningful, real-world objects hidden in the white spaces on the outsides. Saguinetti worked with his adviser Mary Peterson, a professor of psychology and director of the UA's Cognitive Science Program, and with John Allen, a UA Distinguished Professor of psychology, cognitive science and neuroscience, to monitor subjects' brainwaves with an electroencephalogram, or EEG, while they viewed the objects.
"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?"The answer, Sanguinetti's data indicates, is yes." (Medicalxpress.com)