Why is visually guided behaviour less affected by brain damage than visual perception?
Abstract
The idea that the visual cortex can be subdivided into a stream for perception and another one for visually-guided action has had a major impact on visual neuroscience during the last two decades. I will argue that the core claim of this model rests to a large extent on the observations that visually-guided action seems to be less affected by selective damage to visual areas in the brain and seems to be less influenced by the distorting effect of pictorial illusions than visual perception. An alternative account to explain this impressive visuomotor robustness will be presented. I will discuss findings from DF - a patient with damage to the ventral visual stream who suffers from profound visual form agnosia - and findings from the world of visual illusions to support this alternative account.