Presentation

Search Abstracts | Symposia | Slide Sessions | Poster Sessions | Poster Slams

Anomalous morphology of the inferior frontal cortex in children with developmental language disorder

Poster E5 in Poster Session E, Saturday, October 8, 3:15 - 5:00 pm EDT, Millennium Hall
Also presenting in Poster Slam E, Saturday, October 8, 3:00 - 3:15 pm EDT, Regency Ballroom

Nilgoun Bahar¹, Salomi Asaridou¹, Saloni Krishnan², Gabriel Cler³, Kate Watkins¹; ¹Wellcome Centre for Integrative Neuroimaging, Department of Experimental Psychology, University of Oxford, UK., ²Department of Psychology, Royal Holloway, University of London, UK, ³Department of Speech & Hearing, University of Washington, USA

Developmental language disorder (DLD) is a diagnosis given to children with persistent difficulties in learning their first language without a known cause. With an estimated prevalence of 7%, children with DLD are at a higher risk of behavioural, emotional, social, and academic problems. Our knowledge of the underlying brain abnormalities associated with DLD is limited. Only a handful of studies have examined the neural basis of DLD to date, and even fewer have focused on its anatomical correlates, with mixed results. Inconsistencies in findings have been attributed to the heterogenous nature of DLD, co-occurring diagnoses, small sample sizes, and differences in statistical methods, participant age range, and diagnostic criteria for DLD. In this study, we address some of these issues by reporting our findings from the Oxford BOLD study, the largest neuroimaging dataset of DLD to date. Brain images were available in 158 school-age children aged 10-16 years with different levels of language ability. Our criteria for DLD were non-verbal IQ > 70 and performance of 1 SD below the normative mean on two or more of five standardized language assessments. Fifty-seven children met criteria for DLD (M = 12.35 years, 41 males), a further 26 had a history of speech and language problems but did not meet criteria for DLD (HSL group; M = 12.19 years, 22 males) and the remaining 75 were typically developing controls (TD group; M = 12.47 years, 43 males). We used FreeSurfer to conduct exploratory analyses of the T1-weighted brain images. From this, we hypothesized that there would be differences between TD children and those with DLD in the cortical morphology (i.e., area, thickness, and volume) of perisylvian regions relevant for language. Furthermore, we predicted these measures would be correlated with children’s language proficiency scores (calculated from a two-factor confirmatory model) across the whole group. Gender and age were included as covariates of no interest in all analyses. Monte Carlo simulation was used to correct for multiple comparisons (thresholded at a vertex-wise p < 0.001, cluster-wise p < 0.05). The TD-DLD group comparison revealed significantly lower area in DLD in: (i) strikingly symmetric portions of the left and right anterior inferior frontal gyrus, including pars orbitalis and the anterior insula; (ii) right lateral ventral temporal cortex (mid fusiform gyrus). These areas also showed significant volume reductions in children with DLD, but the two groups did not differ in measures of cortical thickness. Correlational analysis revealed a positive relationship between children’s language factors and area in the same anterior portions that showed group differences (i.e., the left and right inferior frontal cortex). Posteriorly, these scores correlated positively with area in left lateral ventral temporal cortex. Our findings provide evidence for abnormal morphology in the inferior frontal and inferior temporal cortex of children with DLD. These results might reflect differences in cortical development of areas necessary for normal language development or a failure of these areas to specialize for language function due to the language impairment itself. Future longitudinal studies will elucidate this causal relationship

Topic Areas: Disorders: Developmental, Development