Sex differences in the spatial representation of number.

Abstract

There is a large body of accumulated evidence from behavioral and neuroimaging studies regarding how and where in the brain we represent basic numerical information. A number of these studies have considered how numerical representations may differ between individuals according to their age or level of mathematical ability, but one issue rarely considered is whether the representational acuity or automaticity of using numerical representations differs between the sexes. We report 4 studies that suggest that male participants show a stronger influence of the spatial representation of number as revealed through the spatial numerical association of response codes (SNARC) effect, through the numerical distance effect (NDE), and through number-line estimations. Evidence for a sex difference in processing number was present for parity decisions (Experiment 1), color decisions (Experiment 2), number-line estimations (Experiment 3), and magnitude decisions (Experiment 4). We argue that this pattern of results reflects a sex difference in either the acuity of representation or reliance upon spatial representations of number, and that this difference may arise due to differences in the parietal lobes of men and women.

Space in numerical and ordinal information: A common construct?

“…This latter result is at odds with the view that differences in ordinal and numerical spatial associations can be attributed to a special overlearned spatial alignment of numbers. Even when taking into account successful inductions of SNARC with larger number sets in comparable color judgment tasks (Bull, Cleland, & Mitchell, 2013;Keus & Schwarz, 2005), a significant weekday SNARC in this (and other) order-irrelevant setting (see Gevers et al, 2004) still disagrees with explaining differences in numerical and non-numerical spatial activations by the increased, overlearned availability of number over weekday sequences. Finally, regarding ordinal and cardinal SNARC effects in the comparison tasks, our analyses suggest different shapes of the effects, with a categorical classification of early and late weekdays, but a linear shaped mapping of numbers onto space.…”

Does your body count? Embodied influences on the preferred counting direction of preschoolers

“…In a typical object-counting task, children are presented with a few elements arranged horizontally in a row, and they are asked to count these elements aloud while touching each of them with a finger. The results usually show that the majority of preschoolers and all or almost all adults from Western countries start counting from the leftmost element and finish at the rightmost one (Knudsen, Fischer, & Aschersleben, 2014;Opfer & Thompson, 2006;Opfer et al, 2010;Opfer & Furlong, 2011;Shaki et al, 2012; but see Bull, Cleland, & Mitchell, 2013;Cipora & Nuerk, 2013;Fischer, 2008;Wood et al, 2008, for stronger inter-individual variability in the SNARC effect). This corresponds to adult-like SNARC effect in which smaller numbers are related to the left side and larger numbers to the right side.…”

Comparing Implicit and Synaesthetic Number–Space Associations: Visuospatial and Verbal Spatial–Numerical Associations of Response Codes

“…In line with our hypotheses, it may be that the likely presence of at least some synaesthetes with left-to-right number forms in SNARC experiments is driving the SNARC effect to some extent (or at least making the SNARC effect appear stronger than it really is); when synaesthetes are not present, the SNARC effect diminishes. Another possible explanation is that the mainly female participant group has diminished the SNARC effect (see Bull, Cleland, & Mitchell, 2013), though given that the synaesthete group is also largely female we would expect to see a diminished SNARC effect in both groups.…”