A study of notation dependence in fraction magnitude processing using event related potentials

Increasingly, research emphasizes that learning symbolic fractions (i.e., the quotient or ratio of two whole numbers) is challenging for both children and adults. However, humans and certain non-human animals are capable of representing the proportional relationships between non-symbolic magnitudes (e.g., dot arrays presented in different colors). The specific mechanisms underlying the relationship between symbolic and non-symbolic magnitude processing are still not sufficiently clear. In this study, we employed event-related potential (ERP) technology to investigate the relationship between symbolic and non-symbolic fractions in numerical processing. We found that, compared to symbolic fractions, the N1 component amplitude evoked by non-symbolic fractions was significantly more negative. When participants processed non-symbolic fractions, there was a significant difference in P3 amplitude between far distances and close distances; however, such differences were not observed when processing symbolic fractions. These findings lend support to the notion of a representation of fractions that is dependent on notation. This suggests that the processing of symbolic and non-symbolic fractions involves two distinct numerical systems.