Poster B110, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Gray matter volume differences in children with discrepant reading ability or poor reading ability
Audreyana Jagger1, Michelle Kibby1; 1Southern Illinois University
The neurobiological literature on reading disability is often discrepant, which may be related to how a reading disorder is defined (Leonard, 2001). Developmental dyslexia (DD) is often defined as a discrepancy between basic reading ability and IQ, whereas poor readers (PR) are typically defined as scoring below average on measures of basic reading. This study included 106 children, 8-12 years of age (53 male). T1 weighted images were collected on all participants and were analyzed using Voxel Based Morphemetry (VBM). Two, one-way ANCOVAs, with age and gender as covariates, were conducted using the SPM and VBM8 toolboxes. Total brain volume was handled as a nuisance variable. The first ANCOVA compared gray matter volumes between children who met criteria for developmental dyslexia (n = 26) or did not (n = 79). Children with DD showed decreased brain volume in the left fusiform and lingual gyri and occipital lobe. Children with DD showed increased gray matter volume in the left middle and superior temporal gyri. The second ANCOVA compared gray matter volumes between children who met criteria to be a poor reader (n = 27) or did not (n = 78). The children who were PR showed decreased gray matter volume in the left calcarine, cuneus, precentral, postcentral, inferior frontal, and middle frontal gyri. The children with PR showed increased gray matter volume in the right middle frontal gyrus. Thus, whereas both definitions had left occipital stream reductions in volume, the PR group showed additional reductions in other cortical areas.
Topic Area: NEUROANATOMY