Multiple object individuation during numerical Stroop.

To investigate whether semantic information relative to numbers is retained during multiple object individuation, we recorded N2pc--a neural measure of selection/individuation--during a numerical version of the Stroop task. Participants enumerated a varying number of target digits (1 to 4) whose identity was either congruent or incongruent with their numerosity. N2pc amplitudes increased as a function of target numerosity but were little affected by congruency, suggesting that multiple object individuation is a prenumeric stage that does not encode for the number magnitude of the numerosity of the individuated objects.