Inhibiting the Whole Number Bias in a Fraction Comparison Task: An Event-Related Potential Study

INTRODUCTION: People often use heuristics derived from natural number tasks to solve fraction comparison tasks. For instance, one may falsely consider a fraction with a larger natural number to be the larger in magnitude, as in the case of 1/5 vs 1/4. We hypothesized that inhibitory control was needed to overcome this type of bias. METHODS: To test the hypothesis, Event-related potentials (ERP) were collected when participants were conducting fraction comparison tasks that designed with the negative priming paradigm. Twenty-eight adult participants performed three types of fraction comparison tasks: congruent items, incongruent items and neutral items. RESULTS: We found a negative priming effect in terms of response time. Consistently, ERP results demonstrated larger N1 and N2 amplitudes and a smaller P3 amplitude in the test trial than in the control trial. CONCLUSION: These findings indicated that adults still need to inhibit the “larger natural number-larger fraction” misleading strategy when solving fraction comparison tasks with common components.