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The Exploitation of Regularities in the Environment by the Brain

Barlow, Horace (2001) The Exploitation of Regularities in the Environment by the Brain.

Short Abstract:

Past work on the exploitation of statistical regularities of the environment by sensory and cognitive mechanisms is briefly reviewed. Shepard proposed the related idea that the laws of kinematic geometry have been internalised, but these laws are mathematical relations rather than observable statistical regularities, and "internalising" does not specify how they bring advantages. The apparent trajectory of an object when seen successively at two positions could result from perceptual mechanisms that exploit observable statistical regularities as well as from internalising Chasles' rule. In either case, the observations suggest that cortical neurons might usefully be selective for twisting motions rather than pure translations.

Long Abstract:

Statistical regularities of the environment are important for learning, memory, intelligence, inductive inference, and in fact for any area of cognitive science where an information-processing brain promotes survival by exploiting them. This has been recognised by many of those interested in cognitive function, starting with Helmholtz, Mach and Pearson, and continuing through Craik, Tolman, Attneave, and Brunswik. In the current era many of us have begun to show how neural mechanisms exploit the regular statistical properties of natural images. Shepard proposed that the apparent trajectory of an object when seen successively at two positions results from internalising the rules of kinematic geometry, and although kinematic geometry is not statistical in nature, this is clearly a related idea. Here it is argued that Shepard's term, "internalisation", is insufficient because it is also necessary to derive an advantage from the process. Having mechanisms selectively sensitive to the spatio-temporal patterns of excitation commonly experienced when viewing moving objects would facilitate the detection, interpolation, and extrapolation of such motions, and might explain the twisting motions that are experienced. Although Shepard's explanation in terms of Chasles' rule seems doubtful, his theory and experiments illustrate that local twisting motions are needed for the analysis of moving objects and provoke thoughts about how they might be detected.

Keywords:	Chasles' rule, evolution, geometry, perception, redundancy, statistics, twisting.
Subjects:	Biology: Ethology Biology: Evolution Psychology: Cognitive Psychology Computer Science: Statistical Models Psychology: Evolutionary Psychology Neuroscience: Neural Modelling Psychology: Perceptual Cognitive Psychology Philosophy: Philosophy of Mind BBS Special Issues: The Work of Roger Shepard
ID code:	bbs00000425
Deposited by:	Horace Barlow on 01 May 2001