A delay in processing for repeated letters: Evidence from megastudies

Repetitions of letters in words are frequent in many languages. Here we explore whether these repetitions affect word recognition. Previous studies of word processing have not provided conclusive evidence of differential processing between repeated and unique letter identities. In the present study, to achieve greater power, we used regression analyses on existing mega-studies of visual word recognition latencies. In both lexical decision (in English, Dutch, and French) and word naming (in English), there was strong evidence that repeated letters delay visual word recognition after major covariates are partialed out. This delay was most robust when the repeated letters occurred in close proximity but not in immediate adjacency to each other. Simulations indicated that the observed inhibitory pattern of repeated letters was not predicted by three leading visual word recognition models. Future theorizing in visual word recognition will need to take account of this inhibitory pattern. It remains to be seen whether the appropriate adjustment should occur in the representation of letter position and identity, or in a more precise description of earlier visual processes.