Implicit learning of non-linguistic and linguistic regularities in children with dyslexia

Abstract

One of the hallmarks of dyslexia is the failure to automatise written patterns despite repeated exposure to print. Although many explanations have been proposed to explain this problem, researchers have recently begun to explore the possibility that an underlying implicit learning deficit may play a role in dyslexia. This hypothesis has been investigated through non-linguistic tasks exploring implicit learning in a general domain. In this study, we examined the abilities of children with dyslexia to implicitly acquire positional regularities embedded in both non-linguistic and linguistic stimuli. In experiment 1, 42 children (21 with dyslexia and 21 typically developing) were exposed to rule-governed shape sequences; whereas in experiment 2, a new group of 42 children were exposed to rule-governed letter strings. Implicit learning was assessed in both experiments via a forced-choice task. Experiments 1 and 2 showed a similar pattern of results. ANOVA analyses revealed no significant differences between the dyslexic and the typically developing group, indicating that children with dyslexia are not impaired in the acquisition of simple positional regularities, regardless of the nature of the stimuli. However, within group t-tests suggested that children from the dyslexic group could not transfer the underlying positional rules to novel instances as efficiently as typically developing children.

Neurobiological Basis of Language Learning Difficulties

“…Both children and adults with dyslexia showed similar implicit learning to controls in non-sequential contextual cueing tasks 29, 30, 31. Children with SLI also show learning similar to that of age-matched controls in other non-sequential procedural learning tasks such as the pursuit rotor task ([7], but see [32]); they do not differ from controls in eyeblink conditioning , which engages corticocerebellar circuits 33, 34.…”

Singh, Samara, & Wonnacott (pre-print). Statistical and explicit learning of graphotactic patterns with no phonological counterpart: Evidence from an artificial lexicon study with 7–8-year-olds and adults

“…In similar implicit learning tasks, Nigro, Jiménez-Fernández, Simpson and Defior (2015; 2016) also found significant learning of letter constraints among 8-year-old Spanish-speaking children: Four-letter pronounceable strings (e.g., mifo), and nonlinguistic stimuli (sequences of shapes), both of which adhered to constraints introduced during exposure (e.g., for letters strings, "stimuli only start with m, l, t-never with f, n, or s"), were reliably learnt by typically developing children and, to some extent, by children diagnosed with dyslexia. Note that in neither of the experiments by Samara and colleagues nor in the study by Nigro et al (2015Nigro et al ( , 2016, were participants prevented from reading the nonwords aloud, an issue we return to in the "Current study" section.…”

“…There is no similar work with children, presumably due to the increased demands of using unfamiliar symbols that necessitate longer training. Nigro et al (2016), though, manipulated unconditional (positional) patters within shape sequences and these were learnt by 8-year-olds. The present study asks whether more complex context-based graphotactic constraints with no phonotactic counterpart, can be learnt by children (and adults) under brief incidental conditions.…”

Artificial Grammar Learning in Dyslexic and Nondyslexic Adults: Implications for Orthographic Learning

“…However, chunk strength sensitivity was analyzed by separate one-sample t tests, against chance, on the proportion of "yes" responses for high chunk strength items and the proportion of "yes" responses for low chunk strength items; this approach may confound participants' sensitivity and response criterion (signal detection theory; Macmillan & Kaplan, 1985). Nigro, Jiménez-Fernández, Simpson, and Defior (2015) used an AGL variant to assess Spanish dyslexic children's ability to implicitly learn and generalize over simple letter-position patterns (e.g., A can begin letter strings, B cannot) embedded either within linguistic or nonlinguistic strings. Regardless of stimulus format, there was no statistical evidence of impairment among dyslexic children.…”

“…The two adult studies are silent on this question, and in studies with dyslexic children, Nigro et al (2015) did not control for chunk strength, while Pavlidou et al's (2010) study did not provide the most stringent analysis of chunk strength sensitivity.…”