Hidden in plain sight: Impaired visual statistical learning might contribute to reading difficulties in dyslexia

Abstract

Objective: The objective of the current study was to determine if dyslexics show deficiencies in visual statistical learning (VSL). Research suggests that reading abilities and literacy-related skills vary in accordance with people´s capacity for VSL. Therefore, it would be expected that an impaired capacity for VSL might contribute to the reading difficulties of dyslexics. Evidence for this comes from research revealing that the visual word form area, a brain region involved in the processing of words, is recruited in VSL. This brain region has consistently been found to be hypoactive in dyslexics. Method: 40 diagnosed dyslexics and 40 matched typical readers participated in the study. Two participants that misunderstood the instructions and their matched counterparts were excluded. Learning was measured with a visual test of temporal statistical learning and a shape recognition control test. A questionnaire assessed whether VSL was explicit to any degree. Results: Dyslexics are impaired in VSL about temporal regularities in comparison to typical readers. Conclusion: Reading difficulties in dyslexia might partially be caused by visual statistical learning deficits. The hypoactivity of the visual word form area in dyslexics could reflect a failure to recycle the region to the processing of words through the mediation of a perceptual statistical learning mechanism.