Hybrid model of price pair comparisons: evidence from an event-related potential study

It remains unclear whether number and unit are represented holistically (i.e. number and unit were processed as a whole) or compositionally (number and unit were processed separately) in the brain. The current study asked participants to compare price pairs with different monetary units that were presented serially. The close and far distances were defined in terms of the overall magnitude between two prices. Electrophysiological results showed that the distance effects were observed on the N2 component at the frontal regions, with far distances eliciting more negativity than close distances. This result suggests that participants compute the holistic price magnitudes before comparing them. Furthermore, a congruence effect was observed in the parietal regions. Incongruent prices elicited more negative amplitude than congruent prices on the N2 component, which implied that numbers and monetary units were processed separately over the same time course. Taken together, these findings suggest that numbers and monetary units are represented holistically and compositionally, which supports the hybrid model.