“…On the basis of previous literature, we hypothesized that arithmetic incongruities (i.e., math operations paired to an incorrect result) would considerably reduce the amplitude of P300 responses, whose amplitude would be increased by correct solutions. P300 component (or P3b) is one of the most studied brain potentials linked to categorization and decisional processes (e.g., Johnson, ; Kirschner, Cruse, Chennu, Owen, & Hampshire, ; Polich, ) in addition to other functions, and it is always larger to congruent than incongruent pairs (e.g., Bach, Gunter, Knoblich, Prinz, & Friederici, ; Farwell, Richardson, Richardson, & Furedy, ; Kałamała, Szewczyk, Senderecka, & Wodniecka, ; Proverbio, Calbi, Manfredi, & Zani, ). It also reflects response certainty and subjective confidence in making a decision (e.g., Dröge, Fleischer, Schlesewsky, & Bornkessel‐Schlesewsky, ).…”