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

methodological problems. In most of these studies (e.g., Zhang & Wang, 2005; Dehaene,
Dupoux, & Mehler, 1990) a fixed standard ending on five such as 55 or 65 was used.
Thereby, unit distance was limited to rather small values with a maximum of 4 (e.g., 55_79).
However, already Nuerk et al. (2001) observed that the compatibility effect was more
pronounced for large unit distances (i.e., 4 - 8) and weaker or even not significant for small
unit distances (i.e., 1 - 4). Thus, it is not very surprising that unit-based effects such as the
compatibility effect have not been observed in studies using a fixed standard ending on 5 (see
also Nuerk & Willmes, 2005 as well as Study 1 for a more detailed discussion of this point).
However, by the time Study 1 was conducted the paper by Ganor-Stern and colleagues (2008)
was not yet published so the issue of simultaneous vs. sequential presentation was not tackled
in this study but should nevertheless be discussed.
Sequential vs. parallel presentation of to-be-compared numbers
Ganor-Stern et al., (2008) observed a regular compatibility effect only when the to-becompared
numbers were presented simultaneously but not when they were presented
sequentially. From this finding the authors concluded that the internal representation of towdigit
number magnitude representation is holistic in nature rather than decomposed. However,
there are a number of theoretical and methodological problems concerning the validity of the
sequential presentation condition as used by Ganor-Stern et al. (2008). From a theoretical
point of view it may not be entirely appropriate to directly compare simultaneous and
sequential processing conditions without referring to the problem of processing stages
involved in either of the two conditions. Already back in 1977 Banks argued in his
influencing paper on semantic processing in comparative judgements that differences between
simultaneous and sequential presentation conditions may be determined by the direction of
what he called relative coding of the to-be-compared numbers. In the sequential condition
participants may have build up expectations about the first number being the large or smaller
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