Perceptual Coherence : Hearing and Seeing

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Transformation of Sensory
Information Into Perceptual
Information
If we take the reasonable position that perceptual systems
evolved to perceive the spatial and temporal properties of objects
in the world, then the place to begin is with an analysis of the characteristics
of that physical world. 1 For some species, the perceptual world
may consist of specific objects necessary for survival, and therefore
we might look for physiological mechanisms that uniquely detect those
objects (e.g., specific cells in the frog’s tectum, colloquially termed bug
detectors by Lettvin, Maturana, McCulloch, and Pitts (1959) that fire to
small dark convex objects moving relative to the background). For other
species including humans, the perceptual world is ever expanding in
terms of novelty and complexity and therefore we might look for physiological
mechanisms that detect statistical regularities and relationships,
rather than specific things. This suggestion is analogous to Shepard’s
(1981) theory of psychophysical complementarity that physiological
mechanisms and perceptual heuristics evolved in response to physical
regularities. It may be possible to predict the characteristics of peripheral
and central processes by figuring out how such regularities could be
coded optimally.
We should ask a variety of questions:
1. Are there physical regularities in the scenes we normally encounter
(excluding man-made objects that produce sounds at particular frequencies
or that are made up of vertical and horizontal straight lines
meeting at right angles)?
1. It is possible to take a different theoretical stance and argue that the function of sensory
systems is to enable appropriate behavior with or without a conscious percept.
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