Mind, Body, World- Foundations of Cognitive Science, 2013a

a conceptual apparatus. Sooner or later concepts must be grounded in a primitive
causal connection between thoughts and things. (Pylyshyn, 2001, p. 154)
It is the need for such grounding that has led Pylyshyn to propose a theory of visual
cognition that includes characteristics of classical, connectionist, and embodied
cognitive science.
8.7 Situation, Vision, and Action
Why is Pylyshyn’s (2003b, 2007) proposal of preattentive visual indices important?
It has been noted that one of the key problems facing classical cognitive science is
that it needs some mechanism for referring to the world that is preconceptual, and
that the impact of Pylyshyn’s theory of visual cognition is that it provides an account
of exactly such a mechanism (Fodor, 2009). How this is accomplished is sketched
out in Figure 8-8, which provides a schematic of the various stages in Pylyshyn’s
theory of visual cognition.
Referential Links To World
A
B
Distal
Objects
FINST A
FINST B
FINST C
Object
File A
Object
File B
Object
File C
Isotropic Cognition
C
Proximal
Stimulus
Early
Vision
Visual
Cognition
Figure 8-8. Pylyshyn’s theory of preattentive visual indexing provides referential
links from object files to distal objects in the world.
The initial stages of the theory posit causal links from distal objects arrayed in space
in a three-dimensional world and mental representations that are produced from
these links. The laws of optics and projective geometry begin by creating a proximal
stimulus—a pattern of stimulation on the retina—that is uniquely determined, but
because of the problem of underdetermination cannot be uniquely inverted. The
problem of underdetermination is initially dealt with by a variety of visual modules
390 Chapter 8