The role of the written script in shaping mirror-image discrimination: Evidence from illiterate, Tamil literate, and Tamil-Latin-alphabet bi-literate adults

Abstract

Learning a script with mirrored graphs (e.g., d ∕ = b) requires overcoming the evolutionary-old perceptual tendency to process mirror images as equivalent. Thus, breaking mirror invariance offers an important tool for understanding cultural reshaping of evolutionarily ancient cognitive mechanisms. Here we investigated the role of script (i.e., presence vs. absence of mirrored graphs: Latin alphabet vs. Tamil) by revisiting mirror-image processing by illiterate, Tamil monoliterate, and Tamil-Latin-alphabet bi-literate adults. Participants performed two same-different tasks (one orientation-based, another shape-based) on Latin-alphabet letters. Tamil monoliterate were significantly better than illiterate and showed good explicit mirror-image discrimination. However, only biliterate adults fully broke mirror invariance: slower shape-based judgments for mirrored than identical pairs and reduced disadvantage in orientation-based over shape-based judgments of mirrored pairs. These findings suggest learning a script with mirrored graphs is the strongest force for breaking mirror invariance.

Do illiterates have illusions? A conceptual (non)replication of Luria (1976)

“…To conclude, learning to read substantially changes some visual perceptual processes such as mirror image processing and face recognition (e.g. Fernandes et al, 2021;van Paridon et al, 2021). The perception of visual illusions however does not appear to belong to the class of visual processes that can be altered by this evolutionary recent cultural invention.…”

“…Poverty and social factors result in a large number of neurologically normally developed people who did not attend any formal schooling and hence do not know how to read or write Tamil (nor any other) script. Fourth, our participants came from the same pool of people with varying literacy levels that did show effects of literacy on visual processing, namely enhanced mirror image discrimination (Fernandes et al, 2021) and face recognition memory (van Paridon et al, 2021). Fifth, in contrast to previous studies (e.g.…”

“…In other words, effects of reading and writing on cognition are cultural, and many such effects have been observed. Learning to read and write improves phonological awareness (Morais et al, 1979), verbal memory (Demoulin & Kolinsky, 2016;Smalle et al, 2019), mirror image discrimination (Fernandes et al, 2021;Kolinsky et al, 2011;Pegado et al, 2014), visual search (Olivers et al, 2014), face recognition (Van Paridon et al, 2021), prediction in speech (Favier et al, in press;Huettig & Pickering, 2019), and even non-verbal intelligence as measured by Raven's progressive matrices (Hervais-Adelman et al, 2019;Olivers et al, 2014;Skeide et al, 2017).…”

Syntactic priming in illiterate and literate older Chinese adults

“…Literacy substantially changes mind and brain (Dehaene et al, 2015;Huettig et al, 2018). Learning to read and write improves mirror image discrimination (Fernandes et al, 2021;Kolinsky et al, 2011;Pegado et al, 2014), face recognition (Van Paridon et al, 2021), visual search (Olivers et al, 2014), verbal memory (Demoulin & Kolinsky, 2016;Smalle et al, 2019), phonological awareness (Lukatela, et al, 1995;Morais et al, 1979Morais et al, , 1986Prakash et al, 1993), prediction during spoken language processing (Favier, Meyer, & Huettig 2021 in press;Huettig & Pickering, 2019;Mani & Huettig, 2014;Mishra et al, 2012), and even the perception of facial emotions (Eviatar, 1997) and non-verbal intelligence as measured by Raven's progressive matrices (Hervais-Adelman et al, 2019;Olivers et al, 2014;Skeide et al, 2017). Research on the effect of literacy is thus a powerful tool to investigate how the human mind works.…”

The literate mind

“…Research over the last forty years has revealed that literacy, i.e., the ability to read and write, changed humanity enormously not only a societal level, but also transforms individual minds and brains. Literacy enhances phonological awareness (Lukatela et al, 1995;Morais et al, 1979Morais et al, , 1986Prakash et al, 1993), prediction during spoken language processing (Favier et al, 2021;Huettig & Pickering, 2019;Mishra et al, 2012), the perception of facial emotions (Eviatar, 1997), face recognition (Van Paridon et al, 2021), mirror image discrimination (Fernandes et al, 2021;Kolinsky et al, 2011;Pegado et al, 2014), visual search (Olivers et al, 2014), verbal memory (Demoulin & Kolinsky, 2016;Smalle et al, 2019), and Raven's non-verbal intelligence (Hervais-Adelman et al, 2019;Olivers et al, 2014;Skeide et al, 2017). Research on the effect of literacy thus is a powerful tool to investigate how the human mind works.…”