Holistic representation of negative numbers: Evidence from duration comparison tasks

Whether negative numbers are represented componentially as two separate components (a digit and a sign) or represented holistically as a whole is still under debate. The present study investigated the representation of negative numbers via duration comparison tasks that might eliminate the possible influences of the strategies participants usually use when processing numbers. In the duration comparison task, participants are required to compare the durations of two numbers that were presented sequentially, thus the numerical value is irrelevant to the task. Our results showed that negative numbers were processed holistically when positive numbers and negative numbers were presented in separate blocks (Exp. 1). But negative numbers showed a componential representation when positive numbers were intermixed with negative numbers within the same block (Exp. 2). This inconsistency might be due to the spatial separation of the polarity sign and digit components in negative numbers which may remind participants that negative numbers are formed by two components when there are positive numbers as a comparison in the same block. Therefore, when the spatial separation of the polarity sign and digit components in negative numbers was eliminated by using colors to mark the polarity (Exp. 3), the negative numbers were processed holistically even when positive numbers and negative numbers were intermixed. These results suggest that negative numbers are represented holistically and may be prone to be represented componentially when intermixed with positive numbers within the same block.