The cognitive penetrability of perception

The question of the extent to which perception is cognitively penetrated is an ambiguous one. Perception can be understood as a process occurring at the level of vehicles (V-perception) or at the level of content (C-perception) and the factors that are understood as necessary or sufficient for answering the question var accordingly. At the level of vehicles, the architecture in which perceptual processes are implemented, the issue is: to what extent is visual perception informationally encapsulated? That is, to what extent are the processes that properly constitute visual perception modified by informational input from non-perceptual cognitive vehicles? At the level of content, the issue is (roughly): to what extent is perceptual content conceptually structured and/or theory impregnated. The primary focus of this paper is the question of cognitive penetrability at the level of vehicles. However, this question cannot be decided in the absence of a proper understanding of perception at the level of content. It will be argued that proper appreciation of the extended character of C-perception - the way in which such perception is extended both out into the world and through time - reveals most attempts to defend the cognitive impenetrability of V-perception to be misguided.