Perceptual Science Series

Multi-level and dynamic visual object representation in the human brain

Dr. Yaoda Xu

Monday, April 06, 2015, 12:00pm - 07:00pm

Harvard University, Psychology Department

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Visual object perception is a complex cognitive process. Given the same input, processing can occur at multiple distinct levels. At the finest level, we notice object texture and material properties; at the next level, we combine parts for form individual objects; further up the processing hierarchy, we attend to and interact with several objects at the same time; and at the highest level, we perceive entire ensembles of objects. Despite this complexity, human vision has the remarkable ability to effortlessly navigate through these different levels of visual processing and extract information at the appropriate level for the task at hand. This highlights two important issues that are fundamental to understanding visual object perception in the human brain: (1) how is information computed and represented in the brain at each level of the visual processing hierarchy? Are similar or distinct neural mechanisms required at each level? And (2) how is task-relevant visual object information selected and represented? What are the neural mechanisms mediating the moment-to-moment visual object perception in the brain? Using fMRI, our research attempts to address these two questions by examining how texture, parts, objects and ensembles are represented in the human brain and the role of the human parietal cortex in the dynamic representation of visual objects.

Dr. Yaoda Xu