The Effect of Writing Direction and Task-Specific Experience on Mapping Time and Numbers on Space

Mapping time and numbers on space is affected by the writing direction. In two experiments, we searched for an explanation of how writing scripts can influence the mental representation of time and number axes. We presented to participants either 2 months (written in their native language) or two numbers (Arabic numerals), one on the left and the other on the right of the screen, and asked them to judge which number is larger or which month comes later in the year. For the months, Arabic speakers responded more accurately and faster when the correct answer was shown on the left, and the pattern was reversed for the Portuguese. However, this effect was not detected when the numbers were compared. We suggest that the observed effect is not rooted in mental mapping of time on space but is accounted for by automatized behavioral patterns related to habitual information processing. We also found that mathematicians performed better with numbers and worse with month names than nonmathematicians, confirming the direct effect of experience on cognitive processing without involving mental representations of number or time axes.