Factors Explaining Deficits in Reading Acquisition: The Case of Williams Syndrome

Area of Science:

• Neuroscience
• Developmental Psychology
• Genetics

Background:

• Reading acquisition is complex, influenced by various factors, including genetic disorders like Williams syndrome (WS).
• Individuals with WS often exhibit intellectual disability and reading deficits, despite relative oral language strengths.
• Existing research offers conflicting views on whether phonological or visuospatial deficits underlie reading difficulties in WS.

Purpose of the Study:

• To investigate factors influencing single-word identification in French-speaking individuals with Williams syndrome (WS).
• To specifically examine the roles of phonological awareness and visuospatial skills in reading performance within the WS population.
• To explore the heterogeneity of reading skills among adults with WS.

Main Methods:

• The study included 29 French-speaking adults with WS and 192 age- and reading-level-matched controls.
• Participants underwent assessments of reading (decoding, word recognition), vocabulary, phonological awareness, and visuospatial skills.
• Chronological age and nonverbal reasoning were controlled for in the analysis.

Main Results:

• Phonemic awareness emerged as the strongest predictor of single-word identification in the WS group.
• Visuospatial skills showed a contribution to reading performance but were not uniquely significant beyond other factors.
• Nonverbal reasoning skills, but not chronological age or vocabulary, also accounted for some variability in single-word identification.

Conclusions:

• Adults with Williams syndrome display significant heterogeneity in reading abilities, ranging from proficient readers to prereaders.
• The observed reading variability is not unique to WS and shares similarities with profiles seen in other specific learning disabilities.
• A multidimensional perspective is crucial for understanding and addressing the reading deficits associated with Williams syndrome.