No horizontal numerical mapping in a culture with mixed-reading habits

Abstract

Reading habits are thought to play an important role in the emergence of cultural differences in visuo-spatial and numerical tasks. Left-to-right readers show a slight visuo-spatial bias to the left side of space, and automatically associate small numbers to the left and larger numbers to the right side of space, respectively. A paradigm that demonstrated an automatic spatial-numerical association involved the generation of random numbers while participants performed lateral head turns. That is, Westerners have been shown to produce more small numbers when the head was turned to the left compared to the right side. We here employed the head turning/random number generation (RNG) paradigm and a line bisection (LB) task with a group of 34 Iranians in their home country. In the participants’ native language (Farsi) text is read from right-to-left, but numbers are read from left-to-right. If the reading direction for text determines the layout of spatial-numerical mappings we expected to find more small numbers after right than left head turns. Yet, the generation of small or large numbers was not modulated by lateral head turns and the Iranians showed therefore no association of numbers with space. There was, however, a significant rightward shift in the LB task. Thus, while the current results are congruent with the idea that text reading habits play an important role in the cultural differences observed in visuo-spatial tasks, our data also imply that these habits on their own are not strong enough to induce significant horizontal spatial-numerical associations. In agreement with previous suggestions, we assume that for the emergence of horizontal numerical mappings a congruency between reading habits for words and numbers is required.

SNARC for numerosities is modulated by comparative instruction (and resembles some non-numerical effects)

“…This could mean that the left-to-right association stored in the long-term memory is still a more relevant dimension for numerical processing (which might not be the case for animal sizes) and may partially limit flexibility of non-symbolic SNARC caused by instructional modulations. Furthermore, the instruction modulated SNARC in a similar way in Polish and Israeli participants (at least for RT analysis-see Footnote 2), despite obvious differences in reading habits between both groups (Rashidi-Ranjbar et al 2014;Shaki and Fischer 2008;Shaki et al 2009). It should be noted, however, that Hebrew orthography includes the left-to-right reading rule for numbers, which may in some cases support left-to-right spatial-numerical associations (cf.…”

“…by using left and right response buttons. The results pattern obtained from this kind of study usually reflects our cultural reading habits: Participants from left-to-right reading societies respond to relatively small numbers faster with the left button and to relatively large numbers faster with the right button, whereas participants from right-to-left reading societies form an attenuated or even opposite association (Dehaene et al 1993;Rashidi-Ranjbar et al 2014;Shaki et al 2009;Zebian 2005). Moreover, SNARC can be temporarily adjusted to other, less standard rules of ordering numbers.…”

Which numbers do you have in mind? Number generation is influenced by reading direction

“…Recently, Rashidi-Ranjbar et al (2014) tested the influence of spatially directional motor actions (left and right head turns; Loetscher et al 2008) on number generation in right-to-left Farsi readers. The authors interpret their failure to find an influence of spatially directional motor actions on number generation as further evidence that mixed directional reading habits of text and numbers (Farsi: text is read right-to-left, numbers left-to-right) cancel each other out ).…”

Random Movements Generation in Western and Eastern Cultures

“…Moreover, our Iranian participants were familiar with Arabic numbers and fluent with the English language (see the "Participants" section for more details), implying some familiarity with the left to right reading. This is particularly relevant in the light of a recent study (Rashidi-Ranjbar, Goudarzvand, Jahangiri, Brugger, & Loetscher, 2014) showing that lateral head turning does not affect the random number selection in Iranian participants with a low familiarity with the left-to-right reading direction habit (i.e., participants were "beginners" for the English language). We also tested, with the same paradigm, a group of monolingual Western participants (i.e., Australians participants).…”