title: Imaging prior information in the brain.
abstract: In making sense of the visual world, the brain's processing is driven by two factors: the physical information provided by the eyes ("bottom-up" data) and the expectancies driven by past experience ("top-down" influences). We use degraded stimuli to tease apart the effects of bottom-up and top-down processes because they are easier to recognize with prior knowledge of undegraded images. Using machine learning algorithms, we quantify the amount of information that brain regions contain about stimuli as the subject learns the coherent images. Our results show that several distinct regions, including high-level visual areas and the retinotopic cortex, contain more information about degraded stimuli with prior knowledge. Critically, these regions are separate from those that exhibit classical priming, indicating that top-down influences are more than feature-based attention. Together, our results show how the neural processing of complex imagery is rapidly influenced by fleeting experiences.
authors.affiliation: Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. scott@scottgorlin.com
authors.forename: Scott
authors.initials: S
authors.lastname: Gorlin
authors.forename: Ming
authors.initials: M
authors.lastname: Meng
authors.forename: Jitendra
authors.initials: J
authors.lastname: Sharma
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sugihara
authors.forename: Mriganka
authors.initials: M
authors.lastname: Sur
authors.forename: Pawan
authors.initials: P
authors.lastname: Sinha
mesh_terms: D000465:Algorithms; D001185:Artificial Intelligence; D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007858:Learning / Q000502:physiology*; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008959:Models, Neurological; D010775:Photic Stimulation; D012044:Regression Analysis; D014796:Visual Perception / Q000502:physiology*