Diagnostik und Kognitive Neuropsychologie

Range (in)dependency of the SNARC effect

Numbers are associated with space, but it is unclear how flexible these associations are. In this planned study, we will investigate whether the SNARC effect (Spatial-Numerical Association of Response Codes; Dehaene et al., 1993), which describes faster responses to small/large number magnitude with the left/right hand, respectively, is fully flexible (and depends only on relative magnitude within a stimulus set), or not (and depends on absolute magnitude as well). Evidence for relative-magnitude dependency comes from studies observing that numbers 4 and 5 were associated with the right when presented in a 0 – 5 range but with the left in a 4 – 9 range (Dehaene et al., 1993; Fias et al., 1996). However, this important conclusion was drawn solely from the absence of evidence for absolute-magnitude dependency in frequentist analysis in underpowered studies. A closer inspection of those descriptive data suggests absolute magnitude might also matter.

Hence, we will conduct a close replication of Dehaene et al.’s (1993) Experiment 3 and a conceptual replication considering recent advances in SNARC research, investigating absolute- and relative-magnitude dependency by comparing intercepts and SNARC slopes across ranges with Bayesian statistics. To achieve a power of .90 for detecting moderate evidence (Bayes Factor above 3 or below 1/3) for Cohen’s d = 0.15, we will conduct each experiment online with maximum 800 participants, but run sequential analyses with optional stopping at moderate evidence. We hypothesize that both absolute and relative magnitude influence spatial-numerical associations, suggesting the SNARC effect operates on flexible and absolute number representations simultaneously.

Our results are yet to come!


PCI Registered Report and materials

SNARC Flexibility: Range (In)Dependency



Dehaene, S., Bossini, S., & Giraux, P. (1993). The mental representation of parity and number magnitude. Journal of Experimental Psychology: General, 122(3), 371–396. https://doi.org/10.1037/0096-3445.122.3.371

Fias, W., Brysbaert, M., Geypens, F., & D'Ydewalle, G. (1996). The importance of magnitude information in numerical processing: Evidence from the SNARC effect. Mathematical Cognition, 2(1), 95–110. https://doi.org/10.1080/135467996387552