title: The intermixed-blocked effect in human perceptual learning is not the consequence of trial spacing.
abstract: A robust finding in humans and animals is that intermixed exposure to 2 similar stimuli (AX/BX) results in better discriminability of those stimuli on test than does exposure to 2 equally similar stimuli in 2 separate blocks (CX_DX)--the intermixed-blocked effect. This intermixed-blocked effect may be an example of the superiority of spaced over massed practice; in the intermixed, but not the blocked exposure regime, each presentation of a given stimulus (e.g., AX) is separated from the next by the presentation of its partner (BX). Two experiments with human participants replicated the intermixed-blocked effect and showed that the effect was not due to the spacing of exposure trials. A mechanism for the intermixed-blocked effect is proposed, which combines theories from associative learning and memory.
authors.affiliation: School of Psychology, University of New South Wales, Sydney, New South Wales 2052, Australia. chris.mitchell@unsw.edu.au
authors.forename: Chris
authors.initials: C
authors.lastname: Mitchell
authors.forename: Scott
authors.initials: S
authors.lastname: Nash
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Hall
mesh_terms: D001288:Attention; D003118:Color Perception; D004193:Discrimination Learning; D005364:Field Dependence-Independence; D006801:Humans; D008570:Memory, Short-Term; D011939:Mental Recall; D010364:Pattern Recognition, Visual; D011214:Practice, Psychological; D011601:Psychophysics