Orthogonality of patterns does not predict their discriminability.

The Lie algebra of continuous transformation groups proposes a theoretical basis for predicting the discriminability of patterns. Three pairs of orthogonal patterns generated by 1st-order Lie operators were used to test the predictions that (1) pair mates that are orthogonal would be more discriminable than nonorthogonal pair mates and (2) the ease of discrimination for the 3 pairs of orthogonal patterns would be predictable from the relative complexity of the Lie operators that generate them. 18 Mongolian gerbils (Meriones unguiculatus) were trained in a jumping stand to discriminate 3 successive pairs of patterns; training continued to a criterion of 2 consecutive days at 90% correct or better. The 1st prediction was not confirmed, and the 2nd was only partially confirmed. Discriminations, using a grating as the positive or negative stimulus or both, were learned significantly faster than those in which no grating appeared. Results offer no strong support for a model of pattern analysis based on the theory of Lie operators. It is concluded that simple orientation of linear contours, rather than contour orthogonality, is the most salient feature of simple patterns. (French abstract) (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)