The Use of Letter Position Cues in the Visual Processing of Words by Children with an Intellectual Disability and Nondisabled Children

Abstract

TWO EXPERIMENTS were designed to investigate possible deficiencies in strategies used for decoding words by children with an intellectual disability. The experiments focused specifically on the use of letter position cues as aids to word identification. In Experiment 1,20 children with an intellectual disability (ID) aged 10 to 12 years were matched with two groups of nondisabled children, one for mental age (MA) and one for chronological age (CA), on a visual search task, with response times to array types (word, pseudoword, or nonword) and target position in positive arrays as the dependent variable. The ID group showed response time advantages only when the target letter was in the initial position of an array; however both nondisabled groups responded faster when the target letter was in either the initial or final position, compared to the medial position, and this pattern occurred for words (MA group) and words and pseudowords (CA group) but not for nonwords. Experiment 2 extended the investigation to the oral reading of isolated words. In substitution errors made by children with an intellectual disability, the incorrect word tended to resemble the test word only in the initial letter. In errors made by MA‐matched children, however, both the initial and final letters tended to be the same as those in the test word, suggesting that these are salient cues to word recognition. The findings are interpreted with reference to previous work on early reading acquisition and to research which suggests a more generalised deficiency in the acquisition and use of strategies by ID subjects in cognitive tasks.