Negative numbers

Numerals are processed by a phylogenetically old analogue magnitude system. Can culturally new negative numerals be processed using this same representation? Using a comparison task we found that magnitude system is not used in a negative range, rather the sign of a number is processed by subsidiary processes. Our results reveal a

• Sign shortcut strategy. While comparing a positive and a negative number, only the sign of those numbers are considered without processing the values.
• Mirroring mechanism. Comparing two positive numbers is the usual comparison task. However when comparing two negative numbers, the negative sign is “cut”, thus the two numbers now “mirrored” to the positive range are compared also on the magnitude system, and the answer (larger or smaller) is reversed.

Krajcsi, A., & Igács, J. (2010). Processing negative numbers by transforming negatives to positive range and by sign shortcut. European Journal of Cognitive Psychology, 22(7), 1021-1038. https://doi.org/10.1080/09541440903211113

Igács, J., Janacsek, K., & Krajcsi, A. (2007). Processing negative numbers by transforming negatives to positive range and by sign shortcut. In 10th European Congress of Psychology in Prague.
(An earlier version of our experiment on a poster.)

See also the extensive test that investigates and supports our model: Huber, S., Nuerk, H.-C., Willmes, K., & Moeller, K. (2016). A general model framework for multisymbol number comparison. Psychological Review, 123(6), 667–695. https://doi.org/10.1037/rev0000040

Description of the project in Hungarian.