Dissociated Spatial-Arithmetic Associations in Horizontal and Vertical Dimensions.

Dixiu Liu,Qi Chen,Mengjin Li,Tom Verguts,Zekai Ling

doi:10.3389/fpsyg.2017.01741

Dixiu Liu, Qi Chen + Show 3 more

Open Access

https://doi.org/10.3389/fpsyg.2017.01741

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Abstract

Spatial–numerical associations (small numbers—left/lower space and large numbers—right/upper space) are regularly found in elementary number processing. Recently, the interest in this phenomenon has been extended from elementary number processing to mental arithmetic. Many studies have demonstrated horizontal spatial-arithmetic associations, i.e., solving addition or subtraction problems cause spatial shifts of attention rightward or leftward, respectively. However, the role of this effect in the vertical dimension has not been addressed. This is problematic because it leaves the analogy between elementary number processing and arithmetic incomplete. In order to make a strong case for a similarity between elementary number processing and mental arithmetic, a spatial-arithmetic association should be observed in the vertical dimension too. Here, we adopted the target detection paradigm from Liu et al. (2017) to replicate the horizontal spatial-arithmetic association, and meanwhile investigate whether this effect also exists in the vertical direction. Our results confirmed that addition could induce covert movement to right side and subtraction to left side. However, such a spatial-arithmetic association was not found in the vertical dimension. The implication of these findings is discussed.

Highlights

In the past two decades, research has revealed a close link between number and space in elementary number processing (e.g., Dehaene et al, 1993; Fischer et al, 2003; Hubbard et al, 2005; Wood et al, 2008; Chen and Verguts, 2010)
The results indicated that solving addition problems facilitated target detection on the right side, while targets on the left side were detected faster after solving subtraction problems
The finding confirmed that mental arithmetic induces spatial shifts of attention in horizontal space

Summary

Introduction

In the past two decades, research has revealed a close link between number and space in elementary number processing (e.g., Dehaene et al, 1993; Fischer et al, 2003; Hubbard et al, 2005; Wood et al, 2008; Chen and Verguts, 2010). In the seminal study of Dehaene et al (1993), it was demonstrated that (in parity judgment) small numbers are associated with faster left-hand response and larger numbers with faster right-hand responses. This suggested a spatial-numerical association in horizontal space. There is a preference to associate small numbers with the lower part of space and larger numbers with the upper part (Schwarz and Keus, 2004; Gevers et al, 2006; Winter et al, 2015).

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