Daily Archives: March 7, 2008

Reconciling Direct Realism?

Sometimes I sit in class and think about the nature of perception and reality. That sounds cliche, but I often find myself wondering whether I am really perceiving the professor as they give a lecture. What am I looking at? Am I merely perceiving representations, or ideas, in my head, or am I really looking at the external world? How can I reconcile the fact that visual information from the environment must be filtered through my nervous system before it is perceived with the sensation that I am directly looking at the world. On one hand, the representational theory of perception makes sense because it seems like there is always going to be this “gap” between my perception and reality, mediated through my sensory organs. On the other hand, it makes evolutionary sense that animals would develop a direct perceptual system in order to save cognitive resources. “Perception is cheap, representation is expensive.”

So what am I looking at when I perceive the world? Ideas in my head or real objects? James Gibson proposed a solution that he thought solved these dualistic paradoxes when he came up with the concept of the ambient optic array. Light is bouncing all around the environment, reflecting information about surfaces and textures, eventually settling into invariant “visual angles”. It is the information in this ambient optic array that we perceive. We don’t perceive the world. We don’t perceive representations in our head, projected onto a Cartesian theater. We directly pickup information from the invariant visual angles of light in the ambient optic array.

This is a mind/body/world system. It embedded and embodied. It is confusing to talk about sense-data stimulating the retina, and the brain “perceiving” this data, as if it was projected onto our cortex and the mind just mysteriously “reads” the data. This leads to conceptual muddles such as mind/body dualism and the representational theory of perception. Gibson thought it made more sense to talk about a ecologically embedded perceptual system picking up information directly from the environment. The distinction between this information pickup and the representational theory of perception is subtle. The difference lies in the fact that with the representational theory there is this impossible divide between between “internal” world of the mind and the “external” physical world. Somehow information crosses this metaphysical gap. Gibson thought it was much more parsimonious and evolutionarily sound to talk about perception in terms of direct pickup by a holistic agent in the environment. The information in the ambient optic array is structurally isomorphic to the firings of the nervous system, which is embedded in a whole body, capable of moving about in the world. By utilizing this ecological approach to perception, Gibson was able to drop the conceptual muddle of a “mind” perceiving ideas driven by the sense organs, but rather, a Self perceiving the environment through invariant structures in the light reflected in the environment. This is why the phenomenology of perception always puts the environment “out there”, in the world, as opposed to “inside” the internal chambers of the mind.

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Filed under Philosophy, Psychology