Visual spatial constancy and modularity: Does intention penetrate vision? Wayne Wu Ó Springer Science+Business Media B.V. 2012 Abstract Is vision informationally encapsulated from cognition or is it cognitively penetrated? I shall argue that intentions penetrate vision in the experience of visual spatial constancy: the world appears to be spatially stable despite our frequent eye movements. I explicate the nature of this experience and critically examine and extend current neurobiological accounts of spatial constancy, emphasizing the central role of motor signals in computing such constancy. I then provide a stringent condition for failure of informational encapsulation that emphasizes a computa- tional condition for cognitive penetration: cognition must serve as an informational resource for visual computation. This requires proposals regarding semantic infor- mation transfer, a crucial issue in any model of informational encapsulation. I then argue that intention provides an informational resource for computation of visual spatial constancy. Hence, intention penetrates vision. Keywords Consciousness Á Vision Á Corollary discharge Á Modularity Á Informational encapsulation Á Spatial representation 1 Introduction When an object moves in one’s field of view (the visual field), one visually experiences its movement (spatial inconstancy). Underlying this is a change in the retinal image, the projection of the visible world onto the retina. There is also a puzzle: the same change in retinal image can be induced when the eyes saccade, ballistic eye movements performed about two times per second. Yet in this case, the world appears not to move (spatial constancy). Thus, the same retinal image is W. Wu (&) Center for the Neural Basis of Cognition, Carnegie Mellon University, 4400 Fifth Avenue, Suite 115, Pittsburgh, PA 15213, USA e-mail: waynewu@cnbc.cmu.edu 123 Philos Stud DOI 10.1007/s11098-012-9971-y