Yale University School of Medicine

1. SMG/STG AG OT/ VWFA IFG MTG/ITG Yale University School of Medicine time An fMRI comparison of reading disabled adolescents with and without general cognitive difficulty Nicole Landi1,2,3, Stephen J. Frost3, W. Einar Mencl3, Rebecca Sandak3 & Kenneth R. Pugh2,3 1Yale Child Study Center; 2Yale University Scool of Medicine & 3Haskins Laboratories Background Neurobiological circuit associated with skilled reading: Study Methods fMRI Results:RD-D fMRI Results: RD-A Study Results: Behavioral data RD-A - RD-D, printed words RD-A- RD-D, spoken words Participants Full sample: 25 RD children, 13 RD-D, 12 RD-A Age M = 8.2 years fMRI Sample: 7 RD children, 5, RD-D, 2RD-A ALL RD > 90 SS on reading composite (WJ Spelling, Word Attack and passage comprehension) RD-D > 90 on WASI performance IQ RD-A >90 on WASI peformance IQ Identification of RD-A and RD-D Parahippocampal gyrus * LH OT Anterior cingulate bilateral STG/MTG TASKS Behavioral assessments: -Woodcock-Johnson III Tests of Achievement (WJ; Woodcock, McGrew, & Mather, 2001) -Tests of Word Reading Efficiency (TOWRE; Torgesen, Wagner & Rashotte, 1999) -Comprehensive Test of Phonological Processing (CTOPP; Wagner, Torgesen, & Rashotte, 1999) -Peabody Picture Vocabulary Test (PPVT; Dunn & Dunn, 1997) -Wechsler Abbreviated Scale of Intelligence (WASI; The Psychological Corporation, 1999). fMRI task: Event-related fMRI: match/mismatch judgment via button press to auditorally and visually presented targets to a picture cue Mismatched targets include: Printed: words, pseudowords, consonant strings, semantically related words & Spoken: words, pseudowords PIQ RD-A < RD-D, p <.01; Reading RD-D = RD-A • Individuals with reading disability (RD) show less activation in the posterior left hemisphere (LH) reading circuit relative to typically developing readers across a variety of reading tasks (e.g., Pugh et al. 2000) • A substantial number of individuals with RD do not meet formal discrepancy criteria. • Many RD readers also have difficulty in one or more other academic skill domains. In the current study, we explore the question of functional subtypes in RD, examining: • Reading disability with achievement discrepancy (RD-D) • Reading disability with poor general achievement (RD-A). We ask: What are the behavioral and neurobiological markers associated with with RD-A vs. RD-D? Subtests of reading and academic skills RH IFG LH STG/MTG * RH extrastriate & Posterior cingulate bilateral STG STG/ Wernicke’s The only significant difference we observed was for PPVT performance; RD-D >RD A, p = .02 L L Yellow = RD-A> RD-D; Purple = RD-D>RD-A p = .005, FDR correcte; slice numbers = MNI Z coordinates Conclusions Behavior: RD-D and RD-A have comparable performance on many measures of reading and other academic skills. They differ significantly only on measures of IQ and vocabulary. fMRI: For print, RD-A children recruit the parahippocampal region suggesting greater reliance on general memory function for reading. RD-D show greater bilateral temporal activity (STG/MTG), as well as several other RH regions suggesting possible use of semantics to compensate for poor phonological/decoding skills. For spoken words, RD-A children show greater activation in STG relative to RD-D, suggesting that auditory- lexical connections maybe weaker for RD-A children. We also observed greater activity in the occipitotemporal (OT) region for the RD-A group for both modalities; this area is typically underactivated in RD children relative to TD children. This suggests that this part of the LH reading circuit is more intact in RD-A children relative to RD-D children. fMRI Data Acquisition and Analysis We acquired functional images on a Siemens 1.5T Sonata MRI scanner at the Yale University School of Medicine. Subjects recieved 40 trials of each condition across 10 scan runs. Subject activations to the base stimulus conditions were analyzed across subjects with ANOVA. Funding was provided by NICHD R03 HD053409, Landi (PI) & NICHD RO1 HD 048830 Pugh (PI)