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

inhibiting irrelevant information and fact knowledge, and (iii) cognitive set changes, are
selectively activated in the number bisection task. Activation of the intraparietal cortex was
increased when problems were numerically more complex, while activation in the left inferior
parietal cortex, particularly in the left angular gyrus was more related to the retrieval of welllearned
problems and of rule-based information integration. Finally, activation of the right
ventrolateral prefrontal cortex was associated with cognitive set changes complying with
strategy use in the NBT.
We wish to emphasize that the differential activations reported in this study cannot
rely on different task properties since the same task was used in all conditions. Fine-grain
within-task manipulations have been previously used to examine and validate the neural
correlates of one specific number representation (Naccache & Dehaene, 2001; Pinel et al.,
2001). In the present study, different numerical representations were examined within one
task and we suggest that such a within-task approach may be a promising tool to understand
the interplay of different representations in the number processing network.
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