Episodic traces and statistical regularities: Paired associate learning in typical and dyslexic readers

Abstract

Learning visual-phonological associations is a key skill underlying successful reading acquisition. However, we are yet to understand the cognitive mechanisms that enable efficient learning in good readers, and those which are aberrant in individuals with developmental dyslexia. Here, we use a repeated cued-recall task to examine how typical and reading-impaired adults acquire novel associations between visual and phonological stimuli, incorporating a looking-at-nothing paradigm to probe implicit memory for target locations. Cued recall accuracy revealed that typical readers' recall of novel phonological associates was better than dyslexic readers' recall, and it also improved more with repetition. Eye fixation-contingent error analyses suggest that typical readers' greater improvement from repetition reflects their more robust encoding and/or retrieval of each instance in which a given pair was presented: whereas dyslexic readers tended to recall a phonological target better when fixating its most recent location, typical readers showed this pattern more strongly when the target location was consistent across multiple trials. Thus, typical readers' greater success in reading acquisition may derive from their better use of statistical contingencies to identify consistent stimulus features across multiple exposures. We discuss these findings in relation to the role of implicit memory in forming new visual-phonological associations as a foundational skill in reading, and areas of weakness in developmental dyslexia.

Audiovisual Learning in Dyslexic and Typical Adults: Modulating Influences of Location and Context Consistency

“…Most children are able to convert written letters and words into sounds effortlessly, and later retrieve them as a single audiovisual unit, eventually becoming proficient readers. However, some struggle to form novel audiovisual mappings, a difficulty that can persist well into adulthood (Blau et al, 2009;Jones et al, 2013bJones et al, , 2018. Readers with developmental dyslexia exhibit indications of less-integrated grapheme-phoneme representations (Blau et al, 2009(Blau et al, , 2010Blomert, 2011;Warmington and Hulme, 2012;Aravena et al, 2013Aravena et al, , 2018Žarić et al, 2015), a deficit owing in part to their comparatively poorer cross-modal binding skills (Aravena et al, 2013;Jones et al, 2013bJones et al, , 2018Žarić et al, 2015;Albano et al, 2016;Toffalini et al, 2018Toffalini et al, , 2019Garcia et al, 2019).…”

“…However, some struggle to form novel audiovisual mappings, a difficulty that can persist well into adulthood (Blau et al, 2009;Jones et al, 2013bJones et al, , 2018. Readers with developmental dyslexia exhibit indications of less-integrated grapheme-phoneme representations (Blau et al, 2009(Blau et al, , 2010Blomert, 2011;Warmington and Hulme, 2012;Aravena et al, 2013Aravena et al, , 2018Žarić et al, 2015), a deficit owing in part to their comparatively poorer cross-modal binding skills (Aravena et al, 2013;Jones et al, 2013bJones et al, , 2018Žarić et al, 2015;Albano et al, 2016;Toffalini et al, 2018Toffalini et al, , 2019Garcia et al, 2019). Despite the well-known link between audiovisual integration and ultimate reading attainment, the cognitive mechanisms underlying typical and atypical cross-modal binding ability are not yet fully understood.…”

“…Learning to read requires establishing new representations in memory: not only separate representations for novel visual/orthographic and phonological forms, but also correspondences between them. A commonly used task to tap the acquisition of novel visual-phonological mappings is cross-modal paired associate learning (PAL; e.g., Warmington and Hulme, 2012;Wang et al, 2017;Jones et al, 2018;Calabrich et al, 2021), in which participants must learn that a given visual symbol is associated with a particular phonological sequence (typically a pseudoword). This learning process is thought to emulate the associative mechanisms underpinning grapho-phonological mappings in the early stages of literacy development (Hulme et al, 2007;Warmington and Hulme, 2012).…”

“…This learning process is thought to emulate the associative mechanisms underpinning grapho-phonological mappings in the early stages of literacy development (Hulme et al, 2007;Warmington and Hulme, 2012). An extensive body of research demonstrates that readers with dyslexia are generally more error prone on such cross-modal PAL tasks, relative to typical readers (Messbauer and de Jong, 2003;Warmington and Hulme, 2012;Litt and Nation, 2014;Wang et al, 2017;Jones et al, 2018;Toffalini et al, 2018), and, crucially, performance on PAL tasks correlates with individual differences in reading skill (Hulme et al, 2007;Warmington and Hulme, 2012). In particular, visual-verbal PAL ability is a unique predictor of both word recognition and non-word reading (Warmington and Hulme, 2012).…”

“…Recently, Jones et al (2018) examined the role of statistical learning mechanisms and episodic memory in the context of a PAL task, in which groups of readers with dyslexia and typically reading adults learned to associate a sequence of unfamiliar characters (i.e., Mandarin Chinese characters) with consistently paired pseudowords. As participants attempted to retrieve each target's corresponding pseudoword, their eye movements were tracked on the now-blank screen to examine whether they consulted the spatial location of the target item in order to support retrieval.…”