Wheel of Fortune: a Cross-cultural Examination of How Expertise Shapes the Mental Representations of Familiar and Unfamiliar Numerals

Numerals are part of our everyday lives and are regularly viewed in less-than ideal conditions. Mistaking one numeral for another is almost an inevitability, and the cost of these confusions could be insignificant or hugely expensive! Numeral confusions can be explained by distances between our mental representations — how we internally represent the external world — resulting from their perceived similarities; yet, how expertise interacts with the mental space of numerals is largely unexplored. We used an identification paradigm to investigate the mental representations of familiar and unfamiliar numerals (4 sets: Arabic, Chinese, Thai, and non-symbolic dots) in a first-language English and a first-language Chinese speaking cohort. Using Luce’s choice model, we removed the undesired effect of response bias and conducted multidimensional scaling analyses. Results showed that expertise with numerals alters distances in the mental space, that unfamiliar numerals are represented identically across cultures, that non-symbolic numerals (dots) may be represented both perceptually and numerically in the mental space, and that Arabic, Thai and Chinese numerals are represented by their perceptual similarities. The findings and methods of this study provide a principled foundation for future investigations into how expertise shapes people’s mental representations.