When ambiguous displays support two interpretations, observers experience alternations between two competing percepts. This phenomenon, known as perceptual bi-stability, is thought to reveal principles underlying how the brain resolves more common ambiguities. The task of our visual system is to resolve such ambiguities by making interpretations of the display. One way that our visual system resolves ambiguities of an image is to draw information from the context in which an image is embedded. Context can be defined as the spatial and temporal environment of an image. Using ambiguous motion stimuli, we will quantify how stimulus and goal driven context influences the reduction in perceptual ambiguity. Observers will report perceptual states while viewing ambiguous displays, as well as while attending to contextual information. Further, to investigate the mechanisms underlying perceptual bi-stability and how the reduction in ambiguity is achieved due to context, we will measure observers'brain activity in a 3T MR scanner while they report their perceptual states. The experiments will shed light on our understanding of perceptual bi-stability and how contextual input shapes our perceptual outcome both at the behavioral and neural levels. Knowledge gained about the mechanisms supporting the contextual modulation of perceptual bi-stabiilty will be applicable to our understanding of visual deficits. Further, understanding the basic neural mechanisms underlying sensory processing will help improve and aid the formulation of new diagnostic interventions for disorders, such as ADHD, autism, developmental dyslexia and schizophrenia, where contextual processing is compromised.
