Attention, automaticity, and levels of representation in number processing.

Participants performed same-different judgments for pairs of numerals in 2 conditions: numerical matching (responding "same" to pairs such as 2-TWO), or physical matching (responding "different" to pairs such as 2-TWO). In most cases, a distance effect was obtained, with the different responses being slower when the 2 numbers were numerically close together (e.g., 1-2) than when they were further apart (e.g., 1-8). This indicates that numbers were automatically converted mentally into quantities, even when the participants had been told to attend exclusively to their physical characteristics. As postulated by several models of number processing, (e.g., Dehaene, 1992; McCloskey, 1992) Arabic and verbal numerals thus appear to converge toward a common semantic representation of quantities. However, the present results suggest that an asemantic transcoding route might allow for a direct mapping of Arabic and verbal numbers, perhaps by means of a common phonological representation.