chertok%ucbkim%Berkeley@sri-unix.UUCP (04/04/84)
From: chertok%ucbkim@Berkeley (Paula Chertok) [Forwarded from the CSLI bboard by Laws@SRI-AI.] BERKELEY COGNITIVE SCIENCE PROGRAM Spring 1984 IDS 237B - Cognitive Science Seminar Time: Tuesday, April 10, 1984, 11-12:30pm Location: 240 Bechtel HOW THE MIND REFLECTS THE WORLD Roger N. Shepard Department of Psychology, Stanford University Through biological evolution, enduring characteristics of the world would tend to become internalized so that each individual would not have to learn them de novo, through trial and possibly fatal error. The most invariant charac- teristics are quite abstract: (a) Space is locally three- dimensional, Euclidean, and isotropic except for a gravita- tionally conferred unique upright direction. (b) For any two positions of a rigid object, there is a unique axis such that the object can be most simply carried from the one position to the other by a rotation around that axis together with a translation along it. (c) Information avail- able to us about the external world and about our relation to it is analyzable into components corresponding to the invariants of significant objects, spatial layouts, and events and, also, into components corresponding to the tran- sitory dispositions, states, and manners of change of these and of the self relative to these. Having been internal- ized, such characteristics manifest themselves as general laws governing the representation of objects and events when the relevant information is fully available (normal percep- tion), when it is only partially available (perceptual fil- ling in or perceptual interpretation of ambiguous stimuli), and when it is entirely absent (imagery, dreaming, and thought). Phenomena of identification, classification, apparent motion, and imagined transformation illustrate the precision and generality of the internalized constraints. ***** Followed by a lunchbag discussion with speaker ***** *** in the IHL Library (Second Floor, Bldg. T-4) from 12:30-2 ***