The representational space of numerical magnitude: illusions of length.
In recent years, a growing amount of evidence concerning the relationships between numerical and spatial representations has been interpreted, by and large, in favour of the mental number line hypothesis--namely, the analogue continuum where numbers are spatially represented (Dehaene, 1992; Dehaene, Piazza, Pinel, & Cohen, 2003). This numerical representation is considered the core of number meaning and, accordingly, needs to be accessed whenever numbers are semantically processed. The present study explored, by means of a length reproduction task, whether besides the activation of lateralized spatial codes, numerical processing modulates the mental representation of a horizontal spatial extension. Mis-estimations of length induced by Arabic numbers are interpreted in terms of a cognitive illusion, according to which the elaboration of magnitude information brings about an expansion or compression of the mental representation of spatial extension. These results support the hypothesis that visuo-spatial resources are involved in the representation of numerical magnitude.
de Hevia
Maria-Dolores
MD
Università degli Studi di Milano-Bicocca, Milan, Italy. dehevia@wjh.harvard.edu
Girelli
Luisa
L
Bricolo
Emanuela
E
Vallar
Giuseppe
G
D000293:Adolescent; D000328:Adult; D001288:Attention; D032882:Comprehension; D004193:Discrimination Learning; D004215:Distance Perception; D005260:Female; D006801:Humans; D007092:Imagination; D008297:Male; D008433:Mathematics; D009903:Optical Illusions; D009949:Orientation; D010364:Pattern Recognition, Visual; D011340:Problem Solving; D011597:Psychomotor Performance; D011601:Psychophysics; D013028:Space Perception; D055815:Young Adult