Abstract

Human perception is remarkably flexible: we experience vivid 3-D structure under diverse conditions from the seemingly random dots of a ‘magic eye’ stereogram to the aesthetically beautiful, but obviously flat, canvasses of the Old Masters. How does the brain achieve this apparently effortless robustness? Using modern brain imaging methods we are beginning to unpick how different parts of the visual cortex support 3-D perception, tracing different computations in the dorsal and ventral pathways. In this talk I will describe work that combines behaviour, fMRI, TMS and computational analysis. By integrating these methods, I will suggest a division of labour between the processing streams that reflects the different computational goals of (a) maximising separation of signals and (b) reducing variance of estimators.

Biography Andrew Welchman is a Wellcome Trust Senior Research Fellow in the School of Psychology, University of Birmingham. He obtained his undergraduate degree in Psychology at Durham University, and worked on perceptual filling-in and completion for his PhD (University of Newcastle). Thereafter he was an Alexander von Humboldt fellow at the Max Planck Institute for Biological Cybernetics (Germany) where he worked on Bayesian modelling and fMRI. He returned to the UK as a BBSRC David Phillips Fellow in 2005, and took up his Wellcome fellowship in 2011. He was awarded the Applied Vision Association’s Marr Medal in 2010. His active research interests include visual and multisensory perception, rivalry and ambiguity, brain imaging, computational modelling and movement control.