title: Operational momentum and size ordering in preverbal infants.
abstract: Recent evidence has shown that, like adults and children, 9-month-old infants manifest an operational momentum (OM) effect during non-symbolic arithmetic, whereby they overestimate the outcomes to addition problems, and underestimate the outcomes to subtraction problems. Here we provide the first evidence that OM occurs for transformations of non-numerical magnitudes (i.e., spatial extent) during ordering operations. Twelve-month-old infants were tested in an ordinal task in which they detected and represented ascension or descension in physical size, and then responded to ordinal sequences that exhibited greater or lesser sizes. Infants displayed longer looking time to the size change whose direction violated the operational momentum experienced during habituation (i.e., the smaller sequence in the ascension condition and the larger sequence in the descension condition). The presence of momentum for ordering size during infancy suggests that continuous quantities are represented spatially during the first year of life.
authors.affiliation: Department of Psychology, University of Milan-Bicocca, Piazza Ateneo Nuovo 1 (U6), 20126, Milan, Italy. viola.macchicassia@unimib.it.|NeuroMi, Milan Center for Neuroscience, Milan, Italy. viola.macchicassia@unimib.it.
authors.forename: Viola
authors.initials: V
authors.lastname: Macchi Cassia
authors.affiliation: Department of Psychology, Barnard College, Columbia University, New York, USA.
authors.forename: Koleen
authors.initials: K
authors.lastname: McCrink
authors.affiliation: Université Paris Descartes, Sorbonne Paris Cité, Paris, France.|CNRS UMR 8242, Laboratoire Psychologie de la Perception, Paris, France.
authors.forename: Maria Dolores
authors.initials: MD
authors.lastname: de Hevia
authors.affiliation: Department of Psychology, University of Milan-Bicocca, Piazza Ateneo Nuovo 1 (U6), 20126, Milan, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Gariboldi
authors.affiliation: Department of Psychology, University of Milan-Bicocca, Piazza Ateneo Nuovo 1 (U6), 20126, Milan, Italy.|NeuroMi, Milan Center for Neuroscience, Milan, Italy.
authors.forename: Hermann
authors.initials: H
authors.lastname: Bulf
mesh_terms: D002657:Child Development / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003210:Concept Formation; D004193:Discrimination Learning; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D007223:Infant; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods