title: Are numbers grounded in a general magnitude processing system? A functional neuroimaging meta-analysis.
abstract: It is currently debated whether numbers are processed using a number-specific system or a general magnitude processing system, also used for non-numerical magnitudes such as physical size, duration, or luminance. Activation likelihood estimation (ALE) was used to conduct the first quantitative meta-analysis of 93 empirical neuroimaging papers examining neural activation during numerical and non-numerical magnitude processing. Foci were compiled to generate probabilistic maps of activation for non-numerical magnitudes (e.g. physical size), symbolic numerical magnitudes (e.g. Arabic digits), and nonsymbolic numerical magnitudes (e.g. dot arrays). Conjunction analyses revealed overlapping activation for symbolic, nonsymbolic and non-numerical magnitudes in frontal and parietal lobes. Contrast analyses revealed specific activation in the left superior parietal lobule for symbolic numerical magnitudes. In contrast, small regions in the bilateral precuneus were specifically activated for nonsymbolic numerical magnitudes. No regions in the parietal lobes were activated for non-numerical magnitudes that were not also activated for numerical magnitudes. Therefore, numbers are processed using both a generalized magnitude system and format specific number regions.
authors.affiliation: University of Western Ontario, London, Ontario, Canada.
authors.forename: H Moriah
authors.initials: HM
authors.lastname: Sokolowski
authors.affiliation: Ghent University, Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Fias
authors.affiliation: University of Western Ontario, London, Ontario, Canada.
authors.forename: Chuka
authors.initials: C
authors.lastname: Bosah Ononye
authors.affiliation: University of Western Ontario, London, Ontario, Canada. Electronic address: daniel.ansari@uwo.ca.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ansari
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging* / Q000502:physiology*; D001931:Brain Mapping; D059907:Functional Neuroimaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008433:Mathematics; D010775:Photic Stimulation
keywords: Functional magnetic resonance imaging; Neural specialization; Non-numerical magnitude; Nonsymbolic; Numerical magnitude; Symbolic