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

OVERVIEW OVER THE STUDIES INCORPORATED INTO THE PRESENT
THESIS
As already mentioned above, the current thesis set off to investigate the importance of
place-value understanding under different empirical aspects of two-digit number processing.
The two studies of the second section follow up on basic research questions clarifying
representational characteristics of two-digit numbers regarding place-value integration in (i)
behavioural number magnitude comparison task (cf. Study 1) as well as (ii) in an eye-tracking
experiment on addition verification (cf. Study 2). In the third section two studies evaluating
(i) the influence of the place-value structure of the Arabic number system on the development
of the spatial representation of number magnitude (cf. Study 3) as well as (ii) the longitudinal
developmental trajectories of early place-value understanding for later arithmetic performance
will be presented (cf. Study 4). Following on these developmental aspects section 4 addresses
neuropsychological questions: (i) the neural correlates of place-value integration will be
examined in a within task approach using functional magnetic resonance imaging (cf. Study
5) and (ii) the consequences of representational hemi-spatial neglect on place-value
integration will be dealt with in patient study (cf. Study 6). In section 5 a computational
model of two-digit number processing is introduced and validated by its performance in twodigit
number magnitude comparison. Finally, section 6 shall provide a general discussion of
the results of the individual studies together with a conclusive evaluation and further
perspectives for the relevance and the investigation of the representation of the place-value
structure as present in the Arabic number system.
Before presenting each of these studies the most important points reflecting the
motivation and the rationale of these studies shall be considered in turn.
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