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

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.