title: Numbers and space: a cognitive illusion?
abstract: This study investigated the relationships between numerical and spatial representations by means of a bisection task, exploring the view that the core representation of number meaning is spatially organized as a mental number line. In Experiment nos. 1 (bisection of digit strings) and 2 (bisection of flanked lines) spatial biases towards the larger digit were found to be related only to processing of relative magnitude. Experiment nos. 3 (bisection of an unfilled space) and 4 (bisection of flanked lines/unfilled spaces) aimed at disclosing perceptual, attentional, and numerical constraints on the bias induced by the position of the larger digit. This effect is interpreted in terms of a cognitive illusion of length, whereby a spatial bias compensates for the numerical disparity. This seems to operate in a categorical fashion ("small/large"), and to be congruent with the assumption that relatively large numbers are associated with the right side of a mental representational space.
authors.affiliation: Dipartimento di Psicologia, Universitá degli Studi Milano-Bicocca, Edificio U6 Piazza dell'Ateneo Nuovo, 1, 20126, Milano, Italy. lola.dehevia@unimib.it
authors.forename: Maria
authors.initials: M
authors.lastname: Dolores de Hevia
authors.forename: Luisa
authors.initials: L
authors.lastname: Girelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vallar
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D013647:Task Performance and Analysis; D014894:Weights and Measures