Age of Acquisition Effects in Word Reading and Other Tasks

Recent studies have suggested that age of acquisition (AoA) has an impact on skilled reading independent of factors such as frequency. This result raises questions about previous studies in which AoA was not controlled, and about current theories in which it is not addressed. Analyses of the materials used in previous studies suggest that the observed AoA effects may have been due to other factors. We also found little evidence for an AoA effect in computational models of reading which used words that exhibit normal spelling-sound regularities. An AoA effect was observed, however, in a model in which early and late learned words did not overlap in terms of orthography or phonology. The results suggest that, with other correlated properties of stimuli controlled, AoA effects occur when what is learned about early patterns does not carry over to later ones. This condition is not characteristic of learning spelling-sound mappings but may be relevant to tasks such as learning the names for objects.