Encoding order and developmental dyslexia: A family of skills predicting different orthographic components. Issue 1 (January 2015)

• Record Type: Journal Article
• Authors: Romani, Cristina; Tsouknida, Effie; Olson, Andrew
• Is Part Of: Quarterly journal of experimental psychology. Volume 68:Issue 1(2015)
• Page Start: 99
• Page End: 128
• Publication Date: 2015-01
• Subjects: Developmental dyslexia -- Serial order -- Sequential presentation -- Visual impairments -- Lexical learning; Psychology, Experimental -- Periodicals; Psychophysiology -- Periodicals; Psychology, Comparative -- Periodicals; 150.72405
• DOI: 10.1080/17470218.2014.938666
• Languages: English
• ISSNs: 1747-0218

Abstract

We investigated order encoding in developmental dyslexia using a task that presented nonalphanumeric visual characters either simultaneously or sequentially—to tap spatial and temporal order encoding, respectively—and asked participants to reproduce their order. Dyslexic participants performed poorly in the sequential condition, but normally in the simultaneous condition, except for positions most susceptible to interference. These results are novel in demonstrating a selective difficulty with temporal order encoding in a dyslexic group. We also tested the associations between our order reconstruction tasks and: (a) lexical learning and phonological tasks; and (b) different reading and spelling tasks. Correlations were extensive when the whole group of participants was considered together. When dyslexics and controls were considered separately, different patterns of association emerged between orthographic tasks on the one side and tasks tapping order encoding, phonological processing, and written learning on the other. These results indicate that different skills support different aspects of orthographic processing and are impaired to different degrees in individuals with dyslexia. Therefore, developmental dyslexia is not caused by a single impairment, but by a family of deficits loosely related to difficulties with order. Understanding the contribution of these different deficits will be crucial to deepen our understanding of this disorder.