Figure 8.

Mathematical full-brain results. Plotted regions denote the difference in average amplitude between the two-numeral and one-numeral conditions for both the (A) addition task and (B) list task, for all space-time regions in which two-numeral activity was reliably greater than one-numeral activity (by at least 1 nAm and p < 0.05, paired samples t-test) for at least 5 ms over five spatial neighbors. For clarity, non-cortical sources have been removed. Results in the addition task conform to our IPS ROI analysis and show a clear effect in this region at ∼150–300 ms. With respect to the main effect of number of numerals identified in lATL ROI, however, we found that, despite the similarity in ROI activity time courses, the effects near this region in each task are actually quite distinct, differing in location not only to each other but also to the effect observed in the previous linguistic study. Increased activity can also be observed over large parts of the frontal cortex during both tasks.