The Relationship Between Pars Triangularis Morphology and Verbal Short-Term Memory Functioning in Children with Reading Disabilities, ADHD, or Expressive Language Deficits

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Talk; brain

Thursday stream 1 Session 09.00 - 11.10 Length 25 minutes

The Relationship Between Pars Triangularis Morphology and Verbal Short-Term Memory Functioning in Children with Reading Disabilities, ADHD, or Expressive Language Deficits

Michelle Y. Kibby, Judith M. Kroese, Morris J. Cohen and George W. Hynd

The University of Georgia, USA MYKibby@aol.com

Abstract

Children with reading disabilities (RD) often present with poor verbal short-term memory. Research utilising PET technology has found Broca's region, including the pars triangularis, to be involved not only in language output but subvocal rehearsal as well. Hence, it was of interest to determine the relationship between pars triangularis (PTr) morphology and verbal short-term memory performance. Participants included 11 children, ages 8 - 12; 6 of whom had reading disabilities (RD). 4 of the remaining 5 had ADHD; one had expressive language deficits. Participants were administered a battery of tests including measures of verbal short-term memory (e.g., number recall, list recall, and story recall). All children also underwent a MRI scan, and the lengths of the two rami of the PTr were measured. Those with RD did not significantly differ from those without RD on PTr measurements, so groups were combined for further analysis. Results demonstrated a significant relationship between length of the left anterior ascending ramus (AAR) and digits forward, and a modest relationship between AAR and story recall. Lengths of the left anterior horizontal ramus (AHR), right AAR, and AHR were unrelated to memory performance. Further, 3 children (2 with RD and 1 with expressive language deficits) presented with an extra gyrus in the PTr, and when this was included in the measurements, left PTr size was significantly correlated with list learning. Hence, our results support a relationship between structural variation of the pars triangularis and verbal short-term memory regardless of the type of learning problem.