Research on adults' numerical abilities suggests that number representations are spatially oriented. Dehaene et al. (1993) named such association of numbers with spatial response as the “SNARC (i.e., spatial–numerical association of response codes) effect,” wherein the right side (e.g. right hand) responds faster than left side when shown larger numbers (and vice-versa when shown smaller numbers).
Given that the SNARC effect serves as an automaticity index of cognitive process, we assume that the SNARC effect is influenced by familiarity. That is, compared to the numerical notation we are not familiar with (e.g. English words, Chinese characters), Arabic digits are more likely to trigger SNARC effect. To test this assumption, we introduced an adaptive procedure based on a simple perceptual orientation task that equates the mean reaction time difference between Arabic digits and traditional Chinese number words. Our results suggested that the SNARC effect interacted with notation, showing a SNARC effect for Arabic digits, but not for verbal numbers, challenging the view that notation does not affect numerical processes associated with spatial representations.
The SNARC effect can be generated in a relationship between space and other ordinal sequences––even weak ordinal information. We tested the SNARC effect in a color word sequence: Red, Orange, Yellow, Green, Blue, Indigo, and Violet (ROY-G-BIV) and found a reliable SNARC-like effect for Chinese color words, suggesting that without access to any quantitative information or exposure to any previous training, ordinal representation can still activate a sense of space. The results also support the inference that weak ordinal information without quantitative magnitude encoded in the long-term memory can activate spatial representation in a comparison task.
Sources:
Gong, T., Li, B., Teng, L., Zhou, Z., Gao, X., Jiang, T. (2019). The Association between Number Magnitude and Space is dependent on notation: Evidence from an adaptive perceptual orientation task. Journal of Numerical Cognition.
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Yu, S., Li, B., Zhang, M., Gong, T., Li, X., Li, Z., …, & Chen, C. (2020). Automaticity in processing spatial-numerical associations: Evidence from a perceptual orientation judgment task of Arabic digits in frames.PloS One, 15(2), e0229130.
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Zhang, M., Gao, X., Li, B., Yu, S., Gong, T., Jiang, T., Hu, Q., & Chen, Y. (2016). Spatial representation of ordinal information. Frontiers in psychology, 7, 505.
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