The ”Anchoring Deficit” hypothesis (Ahissar et al., Nat Neurosci. 2006) proposed that Dyslexics have a difficultyin automatic extraction of simple stimulus regularities in sound sequences. JaffeDax et al. (J Neurosci. 2015) modelled thesedifficulties as yielding noisy priors.The current study was aimed to assess the impact of long-term regularities in language, which listeners had life long experi-ence with. Our assumption was that this familiarity would enhance Controls’ performance more than Dyslexics’ due to a noisierprior formation among Dyslexics. This question was addressed in a series of experiments - in each there was one condition forwhich information accumulated over the life span could be utilized.In all three experiments Dyslexics did not benefit as much as Controls from the long term statistics associated with the input.These results suggest that Dyslexics could not compensate for the deficit despite multiple exposures to lingual input with thesame statistics.

Dyslexia is a common learning disability, but its core deficit is still under debate. The anchoring deficit hypothesissuggests that dyslexics’ benefit from experimental stimuli statistics is impaired (e.g. Ahissar, 2007). In this study we askedwhether dyslexia is also associated with reduced sensitivity to long-term statistics. Spans for lists of syllables were measured,and indeed, dyslexics benefited less than controls from syllabic frequency. However, dyslexics’ benefit from sequence repetitionwas similar to controls’. In order to dissociate the impact of item familiarity from exposure unrelated factors, native Englishspeakers performed the experiment. They were expected to benefit from repetition, but not from syllabic frequency (in Hebrew).Indeed, that was the case. These data suggest that benefits from long-term distributional statistics are impaired in dyslexia,whereas on-line benefits from sequence repetition are adequate. Moreover, our results suggest different underlying mechanismsfor long-term distribution learning and short-term sequence learning.