title: Speed and accuracy of dyslexic versus typical word recognition: an eye-movement investigation.
abstract: Developmental dyslexia is often characterized by a dual deficit in both word recognition accuracy and general processing speed. While previous research into dyslexic word recognition may have suffered from speed-accuracy trade-off, the present study employed a novel eye-tracking task that is less prone to such confounds. Participants (10 dyslexics and 12 controls) were asked to look at real word stimuli, and to ignore simultaneously presented non-word stimuli, while their eye-movements were recorded. Improvements in word recognition accuracy over time were modeled in terms of a continuous non-linear function. The words' rhyme consistency and the non-words' lexicality (unpronounceable, pronounceable, pseudohomophone) were manipulated within-subjects. Speed-related measures derived from the model fits confirmed generally slower processing in dyslexics, and showed a rhyme consistency effect in both dyslexics and controls. In terms of overall error rate, dyslexics (but not controls) performed less accurately on rhyme-inconsistent words, suggesting a representational deficit for such words in dyslexics. Interestingly, neither group showed a pseudohomophone effect in speed or accuracy, which might call the task-independent pervasiveness of this effect into question. The present results illustrate the importance of distinguishing between speed- vs. accuracy-related effects for our understanding of dyslexic word recognition.
authors.affiliation: Neurobiology of Language, Max Planck Institut für Psycholinguistik Nijmegen, Netherlands ; Neurobiology of Language, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Nijmegen, Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: Kunert
authors.affiliation: Institute of Neuroscience and Psychology, University of Glasgow Glasgow, Scotland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Scheepers
keywords: consistency; dyslexia; phonology; speed-accuracy trade-off; visual word recognition