The brain is able to integrate discrete but aligned contour fragments in cluttered scenes to give rise to global contour perception. Most contour integration theories assume that V1 neurons with similar orientation preferences integrate contour elements through long-range horizontal connections. Here we show that global contours formed by collinear elements embedded in a noisy background are still detectable when the stimuli move behind a narrow slit even if the slit permits only one contour element to be viewed at any given moment. Similar to spatial contour integration, contour integration through slit viewing follows the same rule of collinearity. Further fMRI experiments show that while spatial contour integration engages visual areas as early as V1, contour integration through slit viewing engages higher dorsal and ventral visual areas involved in shape processing, as well as posterior parietal regions involved in visual memory. These results suggest that contour integration does not necessarily involve V1 horizontal connections. High level neural mechanisms can also implement the Gestalt rule of continuity governing contour integration.
Biography
Dr. Kuai is Head and Principle Investigator of Visual Cognition and Virtual Reality Application Lab, The School of Psychology and Cognitive Science, East China Normal University. He received his bachelor degree of science from East China Normal University in 2004 and received PHD from Chinese Academy of Science in 2009. He received postdoctoral training at School of Psychology, University of Birmingham, UK from 2009 to 2012. From 2012 to 2015, Dr. Kuai worked for Philips Research as a Research Scientist. He joined East China Normal University as a faculty member in 2015. His research focuses on the neural mechanism of visual integration in 2D and 3D space utilizing various techniques including virtual reality, fMRI, EEG and TMS.