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Discrete and analogue quantity processing in the parietal lobe: A functional MRI study

Castelli, Fulvia and Glaser, Daniel E. and Butterworth, Brian (2006) Discrete and analogue quantity processing in the parietal lobe: A functional MRI study. Proceedings of the National Academy of Sciences of the United States of America, 103 (12). pp. 4693-4698. ISSN 0027-8424. PMCID PMC1450233.

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The human intraparietal sulcus (IPS) is implicated in processing symbolic number information and possibly in nonsymbolic number information. Specific IPS activity for discrete quantities (numerosities) as compared with continuous, analogue quantity has not been demonstrated. Here we use a stimulus-driven paradigm to distinguish automatic estimation of "how many things" from "how much" and "how long." The discrete analogue response task (DART) uses the perception of hues which can change either abruptly (discrete, numerous stimuli) or smoothly (analogue, nonnumerous stimuli) in space or in time. Subjects decide whether they saw more green or more blue. A conjunction analysis of spatial and temporal conditions revealed that bilateral IPS was significantly more active during the processing of discrete stimuli than during analogue stimuli, as was a parietal-occipital transition zone. We suggest that processing numerosity is a distinct process from processing analogue quantity, whether extended in space or time, and that an intraparietal network connects objects’ segmentation to the estimation of their numerosity.

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Additional Information:© 2006 by The National Academy of Sciences of the USA Communicated by Charles R. Gallistel, Rutgers, The State University of New Jersey, Piscataway, NJ, January 20, 2006 (received for review August 5, 2005) Published online before print March 27, 2006, 10.1073/pnas.0601066103 This work was supported by European Union Research Training Network Grant HPRN-CT-2000-00076 (Neuromath) (to F.C. and B.B.) and Medical Research Council Cooperative Group Grant G9900106 (to D.E.G.). Author contributions: F.C. designed research; F.C. and D.E.G. performed research; F.C. and D.E.G. analyzed data; and F.C. and B.B. wrote the paper. Conflict of interest statement: No conflicts declared.
Funding AgencyGrant Number
European Research Council (ERC)HPRN-CT-2000-00076
Medical Research Council (UK)G9900106
Subject Keywords:discrete stimuli; magnitude processing; nonsymbolic numerical processing; numerosity; analogue stimuli
Issue or Number:12
PubMed Central ID:PMC1450233
Record Number:CaltechAUTHORS:CASpnas06
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:5970
Deposited By: Archive Administrator
Deposited On:09 Nov 2006
Last Modified:03 Jun 2020 19:26

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