Spatialization in working memory is related to literacy and reading direction: Culture “literarily” directs our thoughts

Abstract

The ability to maintain arbitrary sequences of items in the mind contributes to major cognitive faculties, such as language, reasoning, and episodic memory. Previous research suggests that serial order working memory is grounded in the brain's spatial attention system. In the present study, we show that the spatially defined mental organization of novel item sequences is related to literacy and varies as a function of reading/writing direction. Specifically, three groups (left-to-right Western readers, right-to-left Arabic readers, and Arabic-speaking illiterates) were asked to memorize random (and non-spatial) sequences of color patches and determine whether a subsequent probe was part of the memorized sequence (e.g., press left key) or not (e.g., press right key). The results showed that Western readers mentally organized the sequences from left to right, Arabic readers spontaneously used the opposite direction, and Arabic-speaking illiterates showed no systematic spatial organization. This finding suggests that cultural conventions shape one of the most "fluid" aspects of human cognition, namely, the spontaneous mental organization of novel non-spatial information.

The empirical reach of the ´mental whiteboard´: A commentary on Ginsburg et al. (2017)

“…2. While Western participants show a left-to-right bias, Arab speakers show a reversed bias (Guida, Megreya, et al, 2018).…”

“…This renders it difficult to interpret the results: the absence of the ordinal position effect does not necessarily refute the use of spatial coding in the non-verbalized condition. Indeed, instead of reflecting a critical role for semantic processing per se, the Experiment 4 findings may well be explained from the assumed role of reading direction in shaping the filling in of the mental whiteboard (i.e., Guida, Megreya, et al, 2018). Hence, verbalization triggers the language system, and as such generates systematic left-to-right spatial coding for a group of Western participants due to their shared reading experience.…”

“…It is currently not known what other types of spatial coding are usedor can be brought into play upon demandin support of serial order WM. Indeed, with regard to the mental whiteboard metaphor, the critical aspect of the ordinal position effect is the spatial format of serial order information; the left-to-right direction as observed in Western participants is informative only in as much we are interested in, for example, precisely how the mental whiteboard is ´filled in´ (e.g., Guida, Megreya, et al, 2018).…”

“…Even though such flexibility, as implied by the hypothesis, is awaiting dedicated empirical scrutiny, the first indications in support of such flexibility have been reported. For example, Guida, Megreya et al (2018) showed that Arabic speakers use the horizontal axis for serial order coding, but in the reversed direction as compared to speakers of Western languages (i.e., from right to left). Hence, the left-toright direction is not universal, and reading direction shapes the use of the mental whiteboard.…”

“…Hence, whereas it may be tempting to take the absence of the ´classic´ (left-toright) ordinal position effect to indicate an absence of spatial coding for serial order (a trap we may have ourselves fallen victim to, recently; Guida, Megreya, et al, 2018), the above indications for flexibility instigate the alternative that the explored group of participants systematically coded order in (still) a spatial formatbut different from the (horizontal) axis being tested (e.g., along the vertical axis). Moreover, a clear testing of the MWH requires the consideration of individual differences, as participants may each code for serial order in their own, idiosyncratic spatial format (for example guided by preferences, experiences, and/or task-related cues)such that at the group level no systematicity is observed.…”