ERPs across arithmetic operations in a delayed answer verification task.

In order to compare processing across operations, we recorded event-related potentials (ERPs) elicited by both problems and solutions in addition, subtraction, multiplication, and division conditions in a delayed answer verification task. Amplitudes of an early negativity, P300, and late positive component (LPC) elicited by solutions were sensitive to the correctness of the presented answers within operations and differed across operations only for incorrect solutions. The early negativity resembled an N270 rather than an N400. The amplitude of an N300 elicited by problem presentations also differed across operations. Our results indicate that ERPs are sensitive to differences in processing across arithmetic operations in an answer verification task both during presentation of the problems, when production/retrieval processes occur, and during comparison of incorrect presented solutions with expected solutions.