Profile of electrophysiological activity across the arithmetic network. a, Electrode localization of the main seven regions that show the strongest math selectivity in both simultaneous and sequential calculation tasks (inside the dotted line), as well as two control regions that show no math selectivity (generic visual activations in the lateral occipital cortex and motor activations in the PCG). b, HFB time courses for the simultaneous and sequential calculation tasks. Shaded error bars indicate the standard error of the mean across electrodes. The timing of each individual stimuli of the sequential calculation task are marked in the leftmost plot. IOG, inferior occipital gyrus; LOG, lateral occipital gyrus; PCG, precentral gyrus. See Movies 1 and 2.