title: Magnitude representations in Williams syndrome: differential acuity in time, space and number processing.
abstract: For some authors, the human sensitivity to numerosities would be grounded in our ability to process non-numerical magnitudes. In the present study, the developmental relationships between non numerical and numerical magnitude processing are examined in people with Williams syndrome (WS), a genetic disorder known to associate visuo-spatial and math learning disabilities. Twenty patients with WS and 40 typically developing children matched on verbal or non-verbal abilities were administered three comparison tasks in which they had to compare numerosities, lengths or durations. Participants with WS showed lower acuity (manifested by a higher Weber fraction) than their verbal matched peers when processing numerical and spatial but not temporal magnitudes, indicating that they do not present a domain-general dysfunction of all magnitude processing. Conversely, they do not differ from non-verbal matched participants in any of the three tasks. Finally, correlational analyses revealed that non-numerical and numerical acuity indexes were both related to the first mathematical acquisitions but not with later arithmetical skills.
authors.affiliation: Center of Cognitive Neurosciences, Psychological Sciences Research Institute, Catholic University of Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Laurence
authors.initials: L
authors.lastname: Rousselle
authors.forename: Guy
authors.initials: G
authors.lastname: Dembour
authors.forename: Marie-Pascale
authors.initials: MP
authors.lastname: Noël
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D011340:Problem Solving; D018980:Williams Syndrome / Q000503:physiopathology*