A callosal transfer deficit in children with developmental language disorder

Developmental malformation of the corpus callosum: a review of typical callosal development and examples of developmental disorders with callosal involvement

“…The initial suggestion of a causal relationship between callosal malformation and DLD was based on observations that many children with callosal abnormalities had language difficulties and that many children with DLD also had deficits in motor coordination (Njiokiktjien 1983; Njiokiktjien et al 1988). Using a simple sensory-motor IHT test, 7–12-year olds with DLD (both receptive and expressive types) performed significantly worse on the IHT task than the within-hemisphere task, whereas controls’ performance did not differ significantly between conditions (Fabbro et al 2002). The DLD group performed similarly to controls on the same hand responses, but made significantly more errors than controls on opposite hand responses, indicating that the sensory-motor abnormalities observed in DLD are more likely to reflect callosal dysfunction than a general sensory-motor deficit.…”

Aneuploidy: From a Physiological Mechanism of Variance to Down Syndrome

“…Neural network models of the different brain structures have identified cognitive operations that are unique to each structure (268), thus allowing predictions on structural-functional maps in DS. For example, the lower performances of DS in linguistic tasks could be partially explained in terms of impairment of the connectivity of frontocerebellar structures involved in articulation and verbal working memory (107), whereas the reduced long-term memory capacities may be related to the temporal lobes and, specifically, to an hippocampal dysfunction (273). Similarly, the functional dissociation between implicit and explicit memory in DS may be due to the severe cerebellar hypoplasia along with normal morphology of basal ganglia that is observed in these patients (183).…”

“…Recent brain imaging studies on language processing (with auditory stimulation) have shown that temporal and frontal areas of both hemispheres are involved in the processing of connected speech, with the left hemisphere responsible for the bulk of on-line processing of syntactic features and prosody (125,245). Thus the lower performances of DS individuals in linguistic tasks may be also explained in terms of impairment of the frontocerebellar structures involved in articulation and verbal working memory (107).…”

Altered gray matter volumes in language‐associated regions in children with developmental language disorder and speech sound disorder

“…Existing theories suggest an altered hemispheric processing of language in affected children (Badcock, Bishop, Hardiman, Barry, & Watkins, 2012;De Fosse et al, 2004;de Guibert et al, 2011;Fabbro, Libera, & Tavano, 2002;Herbert et al, 2005;Mayes et al, 2015;Njiokiktjien, 1990;Plante, Swisher, & Vance, 1989;Witelson & Rabinovitch, 1972), which may be accompanied by functional and structural deviations from the usual degree of hemispheric dominance (Dubois et al, 2009). Thus, we hypothesized altered gray matter volumes in affected children, with less left-hemispheric gray matter (or more right-hemispheric gray matter), compared to typically developing children.…”