Objective: To examine the effect of word length and several sublexical, and lexico-semantic variables on the reading of Italian children with a developmental reading deficit.
Background: Previous studies indicated the role of word length in transparent orthographies. However, several factors that may interact with word length were not controlled for.
Methods: Seventeen impaired and 34 skilled sixth-grade readers were presented words of different lengths, matched for initial phoneme, bigram frequency, word frequency, age of acquisition, and imageability. Participants were asked to read aloud, as quickly and as accurately as possible. Reaction times at the onset of pronunciation and mispronunciations were recorded.
Results: Impaired readers' reaction times indicated a marked effect of word length; in skilled readers, there was no length effect for short words but, rather, a monotonic increase from 6-letter words on. Regression analyses confirmed the role of word length and indicated the influence of word frequency (similar in impaired and skilled readers). No other variables predicted reading latencies.
Conclusions: Word length differentially influenced word recognition in impaired versus skilled readers, irrespective of the action of (potentially interfering) sublexical, lexical, and semantic variables. It is proposed that the locus of the length effect is at a perceptual level of analysis. The independent influence of word frequency on the reading performance of both groups of participants indicates the sparing of lexical activation in impaired readers.
*Neuropsychology Unit, IRCCS Fondazione Santa Lucia
‡Institute for Cognitive Sciences and Technologies, ISTC-CNR
§Department of Psychology, Sapienza University of Rome
†Bambino Gesù Pediatric Hospital Scientific Institute-IRCCS, Rome, Italy
Supported by a grant from the International Dyslexia Association to Cristina Burani and Pierluigi Zoccolotti.
Reprints: Maria De Luca, PhD, Fondazione Santa Lucia-IRCCS, Via Ardeatina 306, 00179 Roma, Italy (e-mail: firstname.lastname@example.org).
Received for publication April 22, 2008; accepted September 30, 2008
Laura Barca, Cristina Burani, and Pierluigi Zoccolotti are members of the Marie Curie Research and Training Network: Language and Brain (RTN-LAB), funded by the European Commission (MRTN-CT-2004-512141) as part of its “Sixth Framework Program.”