Developmental specialization of the left intraparietal sulcus for symbolic ordinal processing

Authors

Anna A. Matejko, Numerical Cognition Laboratory, Department of Psychology and Brain & Mind Institute, Western University, London ON, Canada; Center for the Study of Learning, Department of Pediatrics, Georgetown University, Washington DC, USA. Electronic address: anna.matejko@georgetown.edu.
Jane E. Hutchison, Numerical Cognition Laboratory, Department of Psychology and Brain & Mind Institute, Western University, London ON, Canada; Mathematical Brain Laboratory & Child Development and Social Policy Laboratory, Department of Psychology, Georgetown University, Washington DC, USA. Electronic address: jeh288@georgetown.edu.
Daniel Ansari, Numerical Cognition Laboratory, Department of Psychology and Brain & Mind Institute, Western University, London ON, Canada. Electronic address: daniel.ansari@uwo.ca.Follow

Document Type

Article

Publication Date

5-1-2019

Journal

Cortex; a journal devoted to the study of the nervous system and behavior

Volume

114

First Page

41

Last Page

53

URL with Digital Object Identifier

10.1016/j.cortex.2018.11.027

Abstract

Symbolic numbers have both cardinal (symbol-quantity) and ordinal (symbol-symbol) referents. Despite behavioural evidence suggesting distinct processing of cardinal and ordinal referents, little consensus has emerged from the neuroimaging literature on whether these processes have shared or distinct neural underpinnings. Moreover, it remains unclear how the neural correlates of cardinal and ordinal processing change with age. To address these unresolved questions, we investigated the neural correlates of cardinal (neural distance effect) and ordinal processing (neural reverse distance effect) in 50 children (ages 7-10) and 26 adults (ages 19-26). We found that adults recruited a largely left lateralized set of fronto-parietal regions for ordinal processing, whereas children showed activation in the right lateral orbital and inferior frontal gyri for both ordinal and cardinal processing. Additional analyses suggested that adults recruited the left intraparietal sulcus (IPS) more than children for ordinal processing, suggesting that the IPS may become increasingly tuned to ordinal symbolic properties over development. Together with previous literature documenting the importance of the left IPS for cardinal processing, our results suggest that cardinal and ordinal processing may share neural substrates in the left IPS and that this region may become specialized for both skills over development.