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

According to the index projection hypothesis, “by anchoring a small number
of imagined objects to real objects in the world, the imaginal world inherits much
of the geometry of the real world” (Pylyshyn, 2003b, p. 378). The classical art of
memory, the method of loci, invokes a similar notion of scaffolding, attempting not
only to inherit the real world’s geometry, but to also inherit its permanence.
8.9 The Bounds of Cognition
The purpose of this chapter was to introduce Pylyshyn’s (2003b, 2007) theory of
visual cognition. This theory is of interest because different aspects of it make contact
with classical, connectionist, or embodied cognitive science.
The classical nature of Pylyshyn’s theory is found in his insistence that part
of the purpose of vision is to make contact with perceptual categories that can be
involved in general cognitive processing (e.g., inference and problem solving). The
connectionist nature of Pylyshyn’s theory is found in his invocation of artificial
neural networks as the mechanisms for assigning and tracking indices as part of
early vision. The embodied nature of Pylyshyn’s theory is found in referential links
between object files and distal objects, the use of indices to coordinate vision and
action, and the use of indices and of referential links to exploit the external world as
a scaffold for seeing and visualizing.
However, the hybrid nature of Pylyshyn’s theory of visual cognition presents us
with a different kind of puzzle. How is this to be reconciled with Pylyshyn’s position
as a champion of classical cognitive science and as a critic of connectionist
(Fodor & Pylyshyn, 1988) and embodied (Fodor & Pylyshyn, 1981) traditions? The
answer to this question is that when Pylyshyn writes of cognition, this term has
a very technical meaning that places it firmly in the realm of classical cognitive
science, and which—by this definition—separates it from both connectionist and
embodied cognitive science.
Recall that Pylyshyn’s (2003b, 2007) theory of visual cognition was motivated
in part by dealing with some of the problems facing purely cognitive theories of
perception such as the New Look. His solution was to separate early vision from
cognition and to endorse perceptual mechanisms that solve problems of underdetermination
without requiring inferential processing.
I propose a distinction between vision and cognition in order to try to carve nature
at her joints, that is, to locate components of the mind/brain that have some principled
boundaries or some principled constraints in their interactions with the rest of
the mind. (Pylyshyn, 2003b, p. 39)
The key to the particular “carving” of the system in his theory is that early vision,
which includes preattentive mechanisms for individuating and tracking objects,
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