Electrophysiological Comparison of Cumulative Area and Non-Symbolic Number Judgments

• Type of Material: Article
• Authors: Justin W Bonny, Morgan State University; Stella Lourenco, Emory University
• Language: English
• Date: 2023-06-20
• Publisher: MDPI AG
• Publication Version: Final Published Version
• Copyright Statement: © 2023 by the authors.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/brainsci13060975
• Title of Journal or Parent Work: Brain Sciences
• Volume: 13
• Issue: 6
• Grant/Funding Information: This research was supported by a grant from the Laney Graduate School at Emory College of Arts and Sciences to J.W.B. and by a Scholar Award from the John Merck Fund to S.F.L.
• Keywords: magnitude representation; ERP; non-symbolic number judgments; congruity effect; ratio effect; approximate number system
• Research Categories: Psychology, General

Abstract

Despite the importance of representing different magnitudes (i.e., number and cumulative area) for action planning and formal mathematics, there is much debate about the nature of these representations, particularly the extent to which magnitudes interact in the mind and brain. Early interaction views suggest that there are shared perceptual processes that form overlapping magnitude representations. However, late interaction views hold that representations of different magnitudes remain distinct, interacting only when preparing a motor response. The present study sheds light on this debate by examining the temporal onset of ratio and congruity effects as participants made ordinal judgments about number and cumulative area. Event-related potentials (ERPs) were recorded to identify whether the onset of such effects aligned with early versus late views. Ratio effects for both magnitudes were observed starting in the P100. Moreover, a congruity effect emerged within the P100. That interactions were observed early in processing, at the same time that initial ratio effects occurred, suggests that number and cumulative area processes interacted when magnitude representations were being formed, prior to preparing a decision response. Our findings are consistent with an early interaction view of magnitude processing, in which number and cumulative area may rely on shared perceptual mechanisms.