Word frequency modulates morpheme-based reading in poor and skilled Italian readers

A previous study reported that, similar to young and adult skilled readers, Italian developmental\r\ndyslexics read pseudowords made up of a root and a derivational suffix faster and more accurately\r\nthan simple pseudowords. Unlike skilled readers, only dyslexic and reading-matched younger children\r\nbenefited from morphological structure in reading words aloud. In this study, we show that word\r\nfrequency affects the probability of morpheme-based reading, interacting with reading ability. Young\r\nskilled readers named low- but not high-frequency morphologically complex words faster than simple\r\nwords. By contrast, the advantage for morphologically complex words was present in poor readers\r\nirrespective of word frequency. Adult readers showed no facilitating effect of morphological structure.\r\nThese results indicate that young readers use reading units (morphemes) that are larger than the singlegrapheme\r\ngrain size. It is argued that morpheme-based reading is important for obtaining reading\r\nfluency (rather than accuracy) in transparent orthographies and is useful particularly in children with\r\nlimited reading ability who do not fully master whole-word processing.