Proceedings of the Annual Meeting of the Cognitive Science Society

People conceptualize both time and numbers as unfoldingalong a horizontal line, either from left to right or from rightto left. The direction of both the mental timeline (MTL) andthe mental number line (MNL) are widely assumed to dependon the direction of reading and writing within a culture.Although experimental evidence supports this assumptionregarding the MTL, there is no clear evidence that readingdirection determines the direction of the MNL. Here wetested effects of reading experience on the direction of boththe MTL and MNL. Participants read English text eithernormally (from left to right) or mirror-reversed (from right toleft). After normal reading, participants showed the space-time associations and space-number associations typical ofWesterners. After mirror reading, participants’ space-timeassociations were significantly reduced but their space-number associations were unchanged. These results suggestthat the MTL and MNL have different experiential bases.Whereas the MTL can be shaped by reading experience, theMNL is shaped by other culture-specific practices throughwhich people experience numbers arrayed in left-right space.