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

## TL;DR

This study shows that the brain processes symbolic and non-symbolic fractions differently, suggesting two distinct systems for numerical understanding.

## Contribution

The study provides new evidence that symbolic and non-symbolic fraction processing involve distinct neural mechanisms.

## Key findings

- Non-symbolic fractions elicited a more negative N1 component compared to symbolic fractions.
- Processing non-symbolic fractions showed a P3 amplitude difference based on distance, unlike symbolic fractions.

## Abstract

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.