Biomedical subjects

Richard Boada

Publications and source records attributed to Richard Boada.

4 recordsLinked to original sources

PubMed2006

Deficient implicit phonological representations in children with dyslexia.

This study tested the segmentation hypothesis of dyslexia by measuring implicit phonological representations in reading-disabled 11- to 13-year-olds. Implicit measures included lexical gating, priming, and syllable similarity tasks designed to reduce metalinguistic demands. Children with dyslexia performed consistently worse than CA and RA controls when more segmental representations were required across all three tasks. Implicit phonological representations were correlated with measures of speech perception, phoneme awareness, and phonological short-term memory, but not rapid automatized naming, and accounted for unique variance in predicting reading ability. Results provide strong support for less mature implicit phonological representations in children with dyslexia.

Awareness↗

PubMed2006

Processing speed deficits in attention deficit/hyperactivity disorder and reading disability.

The goal of the current study was to test whether deficits in processing speed (PS) may be a shared cognitive risk factor in reading disability (RD) and Attention Deficit/Hyperactivity Disorder (ADHD), which are known to be comorbid. Literature on ADHD and RD suggests that deficits on tasks with a speeded component are seen in both of these disorders individually. The current study examined a wide range of speeded tasks in RD, ADHD, comorbid RD+ADHD, and a control group to test whether RD and ADHD have similar profiles of PS deficits, and whether these deficits are shared by the two disorders. The results suggest that a general PS deficit exists in both clinical groups compared to controls, although children with RD demonstrate greater PS deficits than children with ADHD. Two tests (underadditivity and partial correlations) were conducted to test whether these PS deficits are shared. Since we found that PS deficits were underadditive in the comorbid group and that partialling PS reduced the correlation between RD and ADHD, it appears that PS is a shared cognitive risk factor that may help explain the comorbidity of these two disorders.

Adolescent↗

PubMed2005

Linkage of speech sound disorder to reading disability loci.

BACKGROUND: Speech sound disorder (SSD) is a common childhood disorder characterized by developmentally inappropriate errors in speech production that greatly reduce intelligibility. SSD has been found to be associated with later reading disability (RD), and there is also evidence for both a cognitive and etiological overlap between the two disorders. The present study tested whether SSD is linked to replicated risk loci for RD. METHOD: One hundred and eleven probands with SSD and their 76 siblings were tested with measures of speech, phonological memory (Nonword Repetition-NWR), and phonological awareness and genotyped for linkage markers on chromosomes 1p36, 6p22, and 15q21. Both single point and multipoint linkage were tested with multiple methods. RESULTS: The speech and NWR phenotypes were linked to the RD loci on chromosomes 6 and 15, with suggestive results for the RD locus on chromosome 1. CONCLUSIONS: It now appears that several RD loci are pleiotropic for SSD, extending the findings of Stein et al. (2004) for the RD locus on Chromosome 3.

Articulation Disorders↗

PubMed2004

Pre-literacy skills of subgroups of children with speech sound disorders.

BACKGROUND: The existing literature has conflicting findings about the literacy outcome of children with speech sound disorders (SSD), which may be due to the heterogeneity within SSD. Previous studies have documented that two important dimensions of heterogeneity are the presence of a comorbid language impairment (LI) and the persistence of SSD, but these factors have not been examined separately. METHOD: The current study used a 2 x 2 MANOVA design (with follow-up MANCOVAs) to examine how a comorbid language impairment (LI) and the persistence of SSD relate to pre-literacy skills in a sample of 5- to 6-year-old children with SSD. RESULTS: Significant main effects for persistent SSD and LI were obtained, such that each factor was associated with worse performance on pre-literacy tasks, particularly those assessing phonological awareness (even with nonverbal IQ covaried). In addition, even SSD children with normalized speech without LI were found to have deficits on phonological awareness tasks relative to control participants. CONCLUSIONS: These results suggest that a history of SSD and comorbid LI are strong correlates of pre-literacy deficits.

Child↗