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

Table 7: Brain areas activated by multiplicativity (all p < 0.001, voxelwise uncorrected)
Multiplicative > non-multiplicative
Region
Talairach coordinates
x, y, z
t-value
df=16
Left angular gyrus -50, -60, 25 5.24 39 17
Left dorsolateral prefrontal cortex -15, 48, 36 5.31 9 12
Non-multiplicative > multiplicative
Left anterior intraparietal cortex -48, -36, 43 5.23 40 21
Right anterior intraparietal cortex 42, -44, 52 5.96 40 24
Left posterior intraparietal/extrastrate cortex -33, -75, 23 8.12 7/19 201
Right posterior intraparietal/extrastrate cortex 18, -67, 56 8.14 7/19 67
Left dorsolateral prefrontal cortex -45, 7, 25 5.62 46 74
Right dorsolateral prefrontal cortex 56, 13, 24 4.57 46 22
SMA/pre-SMA -3, 20, 43 6.50 8 231
Left frontal operculum -27, 21, 4 4.71 45 29
Right frontal operculum 39, 23, -11 7.09 45 47
Left temporo-occipital junction -45, -64, -7 5.63 19/37 28
BA
Cluster
size k
DISCUSSION
As the behavioural data were extensively discussed in Nuerk et al. (2002) the
following will concentrate on discussing fMRI activation patterns. Results show that specific
numerical representations influence the fMRI signal. Cortical areas activated in the present
study are associated with three groups of cognitive processes: the first one includes a bilateral
fronto-parietal network subserving magnitude processing, symbolic base-10 processing, and
other instrumental aspects of number processing. The second one includes regions in the
dorsolateral prefrontal- and inferior parietal cortex, in particular the left angular gyrus, which
are associated with monitoring of different sources of information and arithmetic fact
knowledge, respectively. The third one involves specific regions in the ventrolateral
prefrontal cortex responsible for cognitive set changing. The determinants of the neural
activation observed in each one of these neural networks will be discussed in turn.
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