Please join CCN and SCGB in the kick off of our first SCGB/CCN Lecture Series, with guest speaker Tony Movshon, NYU and our very own CCN Director, Eero Simoncelli. This lecture will take place in the IDA Auditorium at 162 5th Avenue, on Thursday May 12th from 4:30-6PM, followed by a light reception on the 2nd floor promenade at 162 5th Ave.
Title: Representation of natural visual features in the primate visual system
Abstract: The perception of visual patterns emerges from neuronal activity in a cascade of areas in the primate cerebral cortex. Neurons in the primary visual cortex, V1, represent information about the local orientation and scale of image elements, but visual representations in downstream areas V2 and V4 are more enigmatic. We have probed the early stages of this cascade with "naturalistic" texture stimuli designed to capture key statistical features of natural images. Humans can recognize and classify these synthetic images and are insensitive to distortions that do not alter the local values of these statistics. Neurons in the primary visual cortex, V1, are relatively insensitive to the statistical information in these images. However, in the area immediately downstream, V2, cells respond more vigorously to these stimuli than to matched control stimuli. Further downstream, in area V4, cells show stronger responses to natural images of scenes and objects, which may emerge from another iteration of the same kind of neural computation. Humans show blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD fMRI responses in V1, V2 and V4) that are consistent with the neuronal measurements in macaque. These results constrain hypotheses and models of how information about visual features from the natural world are represented in the visual cortex.