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

eplicate processes of unit-decade integration in number comparison, namely the
compatibility effect. Furthermore, we aimed at investigating in how far the model data
correspond to the empirical data for both comparisons to an external (e.g., Nuerk et al.,
2001, Moeller et al., 2009a) as well as internal standard (cf. Moeller et al., 2009d,
Study 1 of this thesis). Therefore, the data produced by either of the three models was
contrasted to the empirical data of the studies by Moeller et al. (2009a, using a
variable standard, i.e., singling out the larger number of a pair of numbers) and
Moeller et al., 2009d, using an fixed standard, i.e., comparing a given number to an
internally memorized standard).
Taken together, the current thesis aimed at investigating the influence of the place
value structure of the Arabic number system on two-digit number processing in respect of
four different aspects: (i) further clarification of basic representational characteristics of place
value integration in magnitude comparison and addition (cf. Studies 1 and 2), (ii)
investigating the developmental implications of early place value understanding (cf. Studies 3
and 4), (iii) evaluating the neuropsychological correlates of place value integration and its
impairments (cf. Studies 5 and 6), (iv) introducing a computational model of two-digit
number processing validated by empirical results pursuing basic representational questions
(cf. Study 7). In the following, the individual studies, each addressing one of above mentioned
issues, will be presented in turn.
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