fMRI connectivity of expressive language in young children and adolescents

Abstract

Studies of language representation in development have shown a bilateral distributed pattern of activation that becomes increasingly left-lateralized and focal from young childhood to adulthood. However, the level by which canonical and extra-canonical regions, including subcortical and cerebellar regions, contribute to language during development has not been well-characterized. In this study, we employed fMRI connectivity analyses (fcMRI) to characterize the distributed network supporting expressive language in a group of young children (age 4-6) and adolescents (age 16-18). We conducted an fcMRI analysis using seed-to-voxel and seed-to-ROI (region of interest) strategies to investigate interactions of left pars triangularis with other brain areas. The analyses showed significant interhemispheric connectivity in young children, with a minimal connectivity of the left pars triangularis to subcortical and cerebellar regions. In contrast, adolescents showed significant connectivity between the left IFG seed and left perisylvian cortex, left caudate and putamen, and regions of the right cerebellum. Importantly, fcMRI analyses indicated significant differences between groups at 3 anatomical clusters, including left IFG, left supramarginal gyrus, and right cerebellar crura, suggesting a role in the functional development of language.

EEG phase synchronization during semantic unification relates to individual differences in children’s vocabulary skill

“…This may reflect functional connections between activity in (left) temporal and bilateral inferior frontal brain areas, which are thought to be important for retrieving word meanings from memory and unifying them into the context of the sentence, respectively (Zhu et al., 2012). Left temporal and inferior frontal connections are assumed to support the development of skilled top‐down processing of semantic relationships, but until now this has been studied primarily in adults (Skeide & Friederici, 2016; although see Youssofzadeh, Vannest, & Kadis, 2018, for the recent finding of more functional connections between these areas among adolescents versus young children as measured with fMRI and during a verb generation task). Our findings may add to this and provide support for the gradual emergence of these top‐down semantic unification processes throughout the school‐age years, even when listening to relatively simple sentences.…”

The Neural Bases of Tinnitus: Lessons from Deafness and Cochlear Implants

“…g oscillations develop in humans between the onset of hearing function before birth, approximately between the 27th embryonic week and sixth to 12th months after birth (Neville and Bavelier, 2002), with predictions that increased g oscillations, associated with feedforward inhibition, precede the development of increased b oscillations (reflecting feedback inhibition) before 6 months after birth (Sowell et al, 2001;Ortiz-Mantilla et al, 2016). From sixth months onwards, the development of functional connectivity in children's brains proceeds, becoming more clustered and specific for sensory modalities (Sowell et al, 2001;Neville and Bavelier, 2002;Ortiz-Mantilla et al, 2016), a process that is paralleled by enhanced speech comprehension in noise (Obleser et al, 2007;Youssofzadeh et al, 2018) and improvement of attention-driven contrast amplification for auditory stimuli, improved auditory discrimination capacity, and improved temporal discrimination (Sowell et al, 2001;Miller and Buschman, 2013) (Fig. 2C, cortical resolution).…”

Beta synchrony for expressive language lateralizes to right hemisphere in development

“…Left perisylvian cortex, including Broca’s and Wernicke’s areas, is known to support gross language processes in healthy adolescents and adults 1 – 13 . The network becomes increasingly left-lateralized and focal by adolescence 14 , 15 , unless development is disrupted by early neurological insult 16 – 19 .…”