Objects in our environment tend to be grouped in typical contexts. We hypothesize that the human brain extracts such contextual information rapidly and uses it to generate predictions that subsequently guide cognition efficiently. In a series of behavioral and neuroimaging experiments, we have previously revealed the cortical network that is uniquely activated during contextual processing of everyday objects. This network is comprised of three primary foci, located in the parahippocampal cortex, retrosplenial cortex and superior orbital prefrontal cortex. Building on our initial results, we propose fifteen experiments to address three specific aims.
In Aim 1 we will define the relative role and properties of each major component in the cortical network that mediates contextual processing, and characterize the cortical dynamics underlying their orchestration.
In Aim 2 we will study the interaction between contextual processing and object recognition, and will test our model of how context facilitates recognition. Specifically, we propose that contextual information is extracted rapidly based on coarse information in the image, which subsequently derives predictions that facilitate visual object recognition. Finally, Aim 3 is designed to test our proposal that contextual representations include gist information about objects that tend to share the same """"""""context frame,"""""""" as well as information about the typical spatial relations among them. The experiments integrate functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), diffusion tensor imaging (DTI), computational methods and purely cognitive and psychophysical experiments. Scene recognition and contextual associations are fundamentally important for many aspects of our day-to-day lives, and understanding how they are accomplished is essential for any complete theory of the brain. Finally, while the focus of the proposed studies is on basic research, it is anticipated that the characterization of these mechanisms would provide a platform from which to evaluate their dysfunctions during mental illness.
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