title: Storage and retrieval of addition facts: the role of number comparison.
abstract: It is proposed that arithmetical facts are organized in memory in terms of a principle that is unique to numbers--the cardinal magnitudes of the addends. This implies that sums such as 4 + 2 and 2 + 4 are represented, and searched for, in terms of the maximum and minimum addends. This in turn implies that a critical stage in solving an addition problem is deciding which addend is the larger. The COMP model of addition fact retrieval incorporates a comparison stage, as well as a retrieval stage and a pronunciation stage. Three tasks, using the same subjects, were designed to assess the contribution of these three stages to retrieving the answers to single-digit addition problems. Task 3 was the addition task, which examined whether reaction times (RTs) were explained by the model; Task 1 was a number naming task to assess the contribution of the pronunciation stage; Task 2 was a magnitude comparison task to assess the contribution, if any, of the comparison stage. A regression equation that included just expressions of these three stages was found to account for 71% of the variance. It is argued that the COMP model fits not only the adult RT data better than do alternatives, but also the evidence from development of additional skills.
authors.affiliation: Department of Psychology, University College London, UK. b.butterworth@ucl.ac.uk
authors.forename: B
authors.initials: B
authors.lastname: Butterworth
authors.forename: M
authors.initials: M
authors.lastname: Zorzi
authors.forename: L
authors.initials: L
authors.lastname: Girelli
authors.forename: A R
authors.initials: AR
authors.lastname: Jonckheere
mesh_terms: D000328:Adult; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008568:Memory; D009483:Neuropsychological Tests; D011930:Reaction Time