Abstract: Visual perception is closely associated with consciousness, and an important part of visual perception is the ability to infer the properties of objects from time-varying changes in retinal stimulation. Two key properties that are of obvious behavioral relevance are their identity and their velocity relative to the observer. In this presentation I will review old results that show how certain kinds of anesthetics impair the ability of individual neurons in the visual cortex to extract important physical quantities from retinal input. I will then present more recent work that provides a computational account of how these neurons integrate their inputs so as to become selective for important stimulus properties. Finally, I will show how the same computations appear to be at work in visual cortical regions that are responsible for different functions, including the estimation of object identity and velocity.
Mineault, P.J., Khawaja, F.A., Butts, D.A., and Pack, C.C. (2012) Hierarchical processing of complex motion along the primate dorsal visual pathway. Proceedings of the National Academy of Sciences of the USA, 109, E972-980. http://packlab.mcgill.ca/mineaultetal2012.pdf
Pack, C.C., Berezovskii, V.K., and Born, R.T. (2001) Dynamic properties of neurons in cortical area MT in alert and anaesthetized macaque monkeys. Nature, 414, 905-908.http://packlab.mcgill.ca/packetal2001.pdf