Relation of Pattern Spacing to Pattern Discrimination in the Hooded Rat

Abstract

To determine the relation of pattern spacing to improved learning with large pattern-small background combinations, rats were trained with: 1-sq. in. patterns on narrowly-spaced 4-sq. in. backgrounds (NS 1:4); 1-sq. in. patterns on widely-spaced 4-sq. in. backgrounds (WS 1:4); 1-sq. in. patterns on 16-sq. in. backgrounds (1:16). Patterns were closest together for the NS 1:4 condition and the same distance apart for WS 1:4 and 1:16. For a triangle-circle discrimination, learning was best for NS 1:4, poorer for WS 1:4 and poorest for 1:16. For a diamond-square discrimination, NS 1:4 was superior to WS 1:4 and 1:16 which did not differ. Conclusions were that decreased pattern spacing (a) improves learning and (b) is more critical for difficult problems.