title: All for one but not one for all: how multiple number representations are recruited in one numerical task.
abstract: Number processing recruits a complex network of multiple numerical representations. Usually the components of this network are examined in a between-task approach with the disadvantage of relying upon different instructions, tasks, and inhomogeneous stimulus sets across different studies. A within-task approach may avoid these disadvantages and access involved numerical representations more specifically. In the present study we employed a within-task approach to investigate numerical representations activated in the number bisection task (NBT) using parametric rapid event-related fMRI. Participants were to judge whether the central number of a triplet was also its arithmetic mean (e.g. 23_26_29) or not (e.g. 23_25_29). Activation in the left inferior parietal cortex was associated with the deployment of arithmetic fact knowledge, while activation of the intraparietal cortex indicated more intense magnitude processing, instrumental aspects of calculation and integration of the base-10 structure of two-digit numbers. These results replicate evidence from the literature. Furthermore, activation in the dorsolateral and ventrolateral prefrontal cortex revealed mechanisms of feature monitoring and inhibition as well as allocation of cognitive resources recruited to solve a specific triplet. We conclude that the network of numerical representations should rather be studied in a within-task approach than in varying between-task approaches.
authors.affiliation: University Hospital of the RWTH Aachen University, Section Neuropsychology-Department of Neurology, and Interdisciplinary Centre for Clinical Research (IZKF BIOMAT.), Germany. guilherme.wood@sbg.ac.at
authors.forename: Guilherme
authors.initials: G
authors.lastname: Wood
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Nuerk
authors.forename: Korbinian
authors.initials: K
authors.lastname: Moeller
authors.forename: Barbara
authors.initials: B
authors.lastname: Geppert
authors.forename: Ralph
authors.initials: R
authors.lastname: Schnitker
authors.forename: Jochen
authors.initials: J
authors.lastname: Weber
authors.forename: Klaus
authors.initials: K
authors.lastname: Willmes
mesh_terms: D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008433:Mathematics; D008606:Mental Processes / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000033:anatomy & histology / Q000502:physiology; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000502:physiology; D013561:Symbolism