The Impact of Mathematical Proficiency on the Number-Space Association

in PLoS ONE (2014)

A specific instance of the association between numerical and spatial representations is the SNARC (Spatial Numerical Association of Response Codes) effect. The SNARC effect describes the finding that ... [more ▼]

A specific instance of the association between numerical and spatial representations is the SNARC (Spatial Numerical Association of Response Codes) effect. The SNARC effect describes the finding that during binary classification of numbers participants are faster to respond to small/large numbers with the left/right hand respectively. Even though it has been frequently replicated, important inter-individual variability has also been reported. Mathematical proficiency is an obvious candidate source for inter-individual variability in numerical judgments, but studies investigating its influence on the SNARC effect remain scarce. The present experiment included a total of 95 University students, divided into three groups differing significantly in their mathematical proficiency levels. Using group analyses, it appeared that the three groups differed significantly in the strength of their number-space associations in a parity judgment task. This result was further confirmed on an individual level, with higher levels in arithmetic leading to relatively weaker SNARC effects. To explain this negative relationship we propose accounts based on differences in access to qualitatively different numerical representations and also consider more domain general factors, with a focus on inhibition capacities. [less ▲]

Differences in the acuity of the Approximate Number System in adults: The effect of mathematical ability

in Acta psychologica (2013), 144(3), 506-512

It is largely admitted that processing numerosity relies on an innate Approximate Number System (ANS), and recent research consistently observed a relationship between ANS acuity and math ability in ... [more ▼]

It is largely admitted that processing numerosity relies on an innate Approximate Number System (ANS), and recent research consistently observed a relationship between ANS acuity and math ability in childhood. However, studies assessing this relationship in adults led to contradictory results. In this study, adults with different levels of mathematical expertise performed two tasks on the same pairs of dot collections, based either on numerosity comparison or on cumulative area comparison. Number of dots and cumulative area were congruent in half of the stimuli, and incongruent in the other half. The results showed that adults with higher math ability obtained lower Weber fractions in the numerical condition than participants with lower math ability. Further, adults with lower math ability were more affected by the interference of the continuous dimension in the numerical comparison task, whereas conversely higher-expertise adults showed stronger interference of the numerical dimension in the continuous comparison task. Finally, ANS acuity correlated with arithmetic performance. Taken together, the data suggest that individual differences in ANS acuity subsist in adulthood, and that they are related to math ability. [less ▲]

The SNARC effect – Does it depend on the level of mathematical training?

Scientific Conference (2012, February 10)

The relation between the acuity of the ANS and general arithmetic performance

Scientific Conference (2012)

Relationships between number and space processing in adults with and without dyscalculia

in Acta Psychologica (2011), 138

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding ... [more ▼]

A large body of evidence indicates clear relationships between number and space processing in healthy and brain-damaged adults, as well as in children. The present paper addressed this issue regarding atypical math development. Adults with a diagnosis of dyscalculia (DYS) during childhood were compared to adults with average or high abilities in mathematics across two bisection tasks. Participants were presented with Arabic number triplets and had to judge either the number magnitude or the spatial location of the middle number relative to the two outer numbers. For the numerical judgment, adults with DYS were slower than both groups of control peers. They were also more strongly affected by the factors related to number magnitude such as the range of the triplets or the distance between the middle number and the real arithmetical mean. By contrast, adults with DYS were as accurate and fast as adults who never experienced math disability when they had to make a spatial judgment. Moreover, number–space congruency affected performance similarly in the three experimental groups. These findings support the hypothesis of a deficit of number magnitude representation in DYS with a relative preservation of some spatial mechanisms in DYS. Results are discussed in terms of direct and indirect number–space interactions. [less ▲]

The SNARC effect – Does it depend on the level of mathematical training?

Poster (2011)

Behavioural studies show a relation between numbers and space (DeHevia et al., 2008). One instance of this link is the SNARC (Spatial Numerical Association of Response Codes) effect, consisting in faster ... [more ▼]

Behavioural studies show a relation between numbers and space (DeHevia et al., 2008). One instance of this link is the SNARC (Spatial Numerical Association of Response Codes) effect, consisting in faster reaction times responding to small/large digits with the left/right hand respectively (Dehaene et al. 1993). The SNARC effect has often been replicated, but it is also characterized by high inter-subject variability (Wood et al. 2006a,b). Although differences in mathematical skills are an obvious candidate source for SNARC variability, this variable has not yet been explored systematically. While in their seminal study Dehaene and colleagues had included two groups of participants differing in their field of study (science vs. literature), the differences in SNARC effect strengths indicated by the result figures were not tested formally (see also Fischer and Rottmann (2005)). The present study aims to assess the influence of mathematical training, as instantiated by the enrollment in study fields characterized by distinct levels of mathematical requirements, on the SNARC effect. We only included students of either a subject with a strong mathematical focus (e.g. mathematics, computer sciences), or no mathematical requirements at all (e.g. literature, philosophy). Results (N=36; 18/group) yielded a significant overall SNARC effect, i.e. interaction between digit magnitude and response side [F(1,35)=9.51; p=0.004], but no influence of study group on this interaction [F(1,35)=0.92; p=0.345]. Interestingly though, including gender in the ANOVA yielded a significant four-way interaction [F(1,35)=6.34; p=0.017]. These results replicate previous findings in children (Schweiter et al. 2005), interpreted as gender-related differences in mental strategy use. [less ▲]

Developing number-space associations: SNARC effects in a color discrimination task in 11-year-olds

Poster (2011)

Behavioural studies show a relation between numbers and space in adults (DeHevia et al., 2008) and this association arises early in development (Opfer et al., 2010). The SNARC (Spatial Numerical ... [more ▼]

Behavioural studies show a relation between numbers and space in adults (DeHevia et al., 2008) and this association arises early in development (Opfer et al., 2010). The SNARC (Spatial Numerical Association of Response Codes) effect consists in faster reaction times (RTs) responding to small/large digits with the left/right hand respectively (Dehaene et al. 1993). It is thought to reflect the automaticity of the number-space link, since it arises not only during explicit magnitude judgment tasks, but also during magnitude-independent parity judgment tasks. Using a parity task Berch et al. (1999) found a SNARC effect in children of 9.2 years onwards, but not in younger children (7.8 years). One major issue raised was that parity judgments might be too difficult and therefore problematic to test young children (VanGalen&Reitsma, 2008). Hence, we designed a color judgment instead of a parity judgment task and tested 33 children from Grade 6 (mean age 11.4 years, SD 0.6). We also assessed number magnitude access using a magnitude judgment task. The results revealed a significantly negative slope in the color task [t(32)=2.47, p<0.01] and in the magnitude task [t(33)=1.75, p<0.05], reflecting a SNARC effect in both tasks (regression method by Lorch&Myers, 1990). A correlation analysis of the slopes of both tasks revealed a positive relationship (r=0.33, p<0.05) indicating that they partly measure the same processes. These results confirm the presence of robust SNARC effects in 6th-graders and indicate that they occur even using a simple color discrimination task that is strictly independent of semantic number processing. [less ▲]