The influence of the place-value structure of the Arabic number ...

portion of the superior frontal gyrus, both bilaterally. A further activation cluster was
observed in the right medial temporal gyrus (Figure 2A, Table 6).
Possible > impossible: No region exhibited an increase in activation for this contrast at
the voxelwise uncorrected threshold of p = .01.
Impossible > possible: Increased activation in the right ventro-lateral prefrontal cortex
was observed for triplets impossible to bisect by an integer (BA47, Talairach coordinates: 40,
20, -4, k = 10, t(16) = 5.99, p < .001, uncorrected, see Figure 2B and Table 6).
Multiplicative > non-multiplicative: When the triplet was part of a multiplication
table, the left angular gyrus and a small portion of prefrontal cortex was specifically activated
(Figure 3, Table 7).
Table 5: Brain areas activated by problem size (all p < 0.001, voxelwise uncorrected)
Large sum > small sum
Region
Talairach coordinates
x, y, z
t-value
df=16
BA
Cluster
size k
Right extrastriate cortex 33, -90, -3 6.28 19 602
Left strate cortex -9, -81, 6 5.94 17/18 -
Left extrastriate cortex -15, -93, 0 5.03 19 -
Right strate cortex 3, -84, 15 5.07 17/18 -
Left temporo-occipital junction -42, -53, -20 5.82 19/37 28
cerebellum -6, -74, -19 7.49 - 85
Small sum > large sum
Left inferior parietal cortex -48, -62, 47 5.50 39 66
Right inferior parietal cortex 53, -69, 23 5.33 39 26
189