Statistical learning and reading: Visual regularities support affix detection in children aged 6 to 11

We examined the role of visual statistical learning in the way developing readers learn to identify morphemes and code for their typical position within words. A large group of children (N =129; aged 6 to 11 years) were familiarized with a lexicon of pseudo-letter strings, each composed of a random character sequence and an affix-like chunk. Devoid of any linguistic information, chunks could be defined only by their statistical properties – similarly to affixes in the real language, they occurred frequently in a specific position within strings. We found that children were subsequently more likely to attribute a previously unseen string to the novel lexicon if it contained an affix. However, they showed no sensitivity to the within-string affix position. These results demonstrate that developing readers can acquire aspects of morpho-orthographic knowledge via the extraction of visual regularities from the linguistic input. Interestingly, this ability was not reliably modulated by children’s age, reading fluency or morphological awareness, reflecting an early-maturing cognitive capacity. We discuss the importance of incorporating such a fundamental language-agnostic learning mechanism into theories of reading acquisition.