Early Language Abilities and the Underlying Neural Functional Reading Network in Preschoolers

Early childhood is a critical time for language development. Language impairments that go untreated in the early years can result in decreased academic achievement and future mental health concerns. Despite the importance of early language development, very little research has focused on the functional brain systems supporting language in typically developing young children. We investigated relationships between age, language abilities, and the brain’s functional connectivity (FC) patterns seeded from brain areas associated with reading. The study included 50 healthy children aged 2.9-5.6 years (3.8 ± 0.6 years, 21f/29m) who completed a language assessment (NEPSY-II Phonological Processing and Speeded Naming) and underwent functional MRI (magnetic resonance imaging) scanning while watching a movie. Phonological Processing scores positively correlated with FC between the left angular gyrus and contralateral sensorimotor cortices, as well as between the right angular gyrus and the left supramarginal gyrus. Speeded Naming scores positively correlated with FC between the left inferior frontal gyrus, pars triangularis and the left fusiform gyrus, extending to the posterior region of the middle/inferior temporal gyrus and negatively correlated with the precuneus of the default mode network. Despite these variations in the FC patterns associated with speeded naming and phonological processing, both language measures positively correlated with FC between the ROI and the angular gyrus, supramarginal gyrus, and precentral gyrus. Age positively correlated with FC between regions within the ventral language pathway, including the inferior frontal gyrus and middle/inferior temporal gyrus and negatively correlated with FC between ipsilateral language regions and contralateral visual areas within the occipital cortex. The results demonstrate that better language abilities in young children are associated with stronger functional connections between brain regions within the language network identified in older children and adults who can perform more complex language processes

Age-related functional brain changes in young children

Brain function and structure change significantly during the toddler and preschool years. However, most studies focus on older or younger children, so the specific nature of these changes is unclear. In the present study, we analyzed 77 functional magnetic resonance imaging datasets from 44 children aged 2-6 years. We extracted measures of both local (amplitude of low frequency fluctuation and regional homogeneity) and global (eigenvector centrality mapping) activity and connectivity, and examined their relationships with age using robust linear correlation analysis and strict control for head motion. Brain areas within the default mode network and the frontoparietal network, such as the middle frontal gyrus, the inferior parietal lobule and the posterior cingulate cortex, showed increases in local and global functional features with age. Several brain areas such as the superior parietal lobule and superior temporal gyrus presented opposite development trajectories of local and global functional features, suggesting a shifting connectivity framework in early childhood. This development of functional connectivity in early childhood likely underlies major advances in cognitive abilities, including language and development of theory of mind. These findings provide important insight into the development patterns of brain function during the preschool years, and lay the foundation for future studies of altered brain development in young children with brain disorders or injury.Canadian Institutes of Health Research - Project Schem

Pre-reading language abilities and the brain's functional reading network in young children

Early childhood is an important period for language development that lays the foundation for future reading abilities. However, little research has focused on the functional brain systems supporting pre-reading language abilities in typically developing children. Here, we investigated functional connectivity using passive viewing functional magnetic resonance imaging (fMRI) in 50 healthy children aged 2.85-5.07 years (3.84 ​± ​0.60 years, 22 female/28 male). Children completed the NEPSY-II Phonological Processing and Speeded Naming subtests and underwent fMRI while watching a movie of their choice. Functional connectivity was measured between key brain reading areas (bilateral angular gyrus, superior temporal gyrus, and inferior frontal gyrus) and the rest of the brain. Age-adjusted pre-reading scores positively correlated with functional connectivity between (1) the right angular gyrus and superior temporal gyrus, (2) the bilateral angular gyri and right pars triangularis and motor areas, (3) the left superior temporal gyrus and bilateral medial frontal gyrus and right cerebellum, (4) the left pars triangularis and middle occipital gyrus and insula, and (5) the right pars triangularis and the bilateral thalamus. Higher pre-reading scores were associated with stronger negative functional connectivity between (1) the left angular gyrus and auditory cortex, (2) the left superior temporal gyrus and occipital vision areas, (3) the right pars triangularis and medial frontal region, and (4) the right superior temporal gyrus and the posterior cingulate/precuneus. These results suggest better integration of the reading network, as well as its connections with other brain areas that support language or reading, and more dissociation between reading areas and the default mode network, in young children with better pre-reading skills. Our findings show that relationships between functional connectivity and pre-reading language skills are evident in young children even before formal reading instruction.Canadian Institutes of Health Research (CIHR

Developmental trajectories of white matter structure in children with and without reading impairments

Left temporal-parietal white matter structure is consistently associated with reading abilities in children. A small number of longitudinal studies show that development of this area over time is altered in children with impaired reading. However, it remains unclear how brain developmental patterns relate to specific reading skills such as fluency, which is a critical part of reading comprehension. Here, we examined white matter development trajectories in children with dysfluent reading (20 dysfluent and inaccurate readers, 36 dysfluent and accurate readers) compared to non-impaired readers (n = 14) over 18 months. We found typical age-related increases of fractional anisotropy (FA) in bilateral temporal-parietal areas in non-impaired readers, but a lack of similar changes in dysfluent readers. We also found steeper decreases of mean diffusivity (MD) in the right corona radiata and left uncinate fasciculus in dysfluent inaccurate readers compared to dysfluent accurate readers. Changes in diffusion parameters were correlated with changes in reading scores over time. These results suggest delayed white matter development in dysfluent readers, and show maturational differences between children with different types of reading impairment. Overall, these results highlight the importance of considering developmental trajectories, and demonstrate that the window of plasticity may be different for different children. Keywords: Dyslexia, Reading, Fluency, Accuracy, Diffusion tensor imaging, White matte

Image_1_Factors Associated With Successful MRI Scanning in Unsedated Young Children.TIF

<p>Introduction: Young children are often unable to remain still for magnetic resonance imaging (MRI), leading to unusable images. Various preparation methods may increase success, though it is unclear which factors best predict success. Here, in a retrospective sample, we describe factors associated with successful scanning in unsedated young children. We hypothesized that the mock scanner training and fewer behavior problems would result in higher success rates.</p><p>Methods: We recruited 134 children aged 2.0–5.0 years for an MRI study. We compared success between children whose parents opted for mock scanner training (n = 20) or not (n = 114), and evaluated demographic and cognitive factors that predicted success.</p><p>Results: Ninety-seven children (72%) completed at least one MRI sequence successfully on their first try; 64 children (48%) provided high-quality data for all 3 structural imaging sequences. Cognitive scores were higher in successful than unsuccessful children. Children who received mock scanner training were no more likely to be successful than children without, though they had slightly higher scores on T1 image quality.</p><p>Conclusions: Our data shows that scanning with minimial preparation is possible in young children, and suggests limited advantages of mock scanner preparation for healthy young children.Cognitive ability may predict success.</p

Table_1_Factors Associated With Successful MRI Scanning in Unsedated Young Children.DOCX

<p>Introduction: Young children are often unable to remain still for magnetic resonance imaging (MRI), leading to unusable images. Various preparation methods may increase success, though it is unclear which factors best predict success. Here, in a retrospective sample, we describe factors associated with successful scanning in unsedated young children. We hypothesized that the mock scanner training and fewer behavior problems would result in higher success rates.</p><p>Methods: We recruited 134 children aged 2.0–5.0 years for an MRI study. We compared success between children whose parents opted for mock scanner training (n = 20) or not (n = 114), and evaluated demographic and cognitive factors that predicted success.</p><p>Results: Ninety-seven children (72%) completed at least one MRI sequence successfully on their first try; 64 children (48%) provided high-quality data for all 3 structural imaging sequences. Cognitive scores were higher in successful than unsuccessful children. Children who received mock scanner training were no more likely to be successful than children without, though they had slightly higher scores on T1 image quality.</p><p>Conclusions: Our data shows that scanning with minimial preparation is possible in young children, and suggests limited advantages of mock scanner preparation for healthy young children.Cognitive ability may predict success.</p

Image_2_Factors Associated With Successful MRI Scanning in Unsedated Young Children.TIF

<p>Introduction: Young children are often unable to remain still for magnetic resonance imaging (MRI), leading to unusable images. Various preparation methods may increase success, though it is unclear which factors best predict success. Here, in a retrospective sample, we describe factors associated with successful scanning in unsedated young children. We hypothesized that the mock scanner training and fewer behavior problems would result in higher success rates.</p><p>Methods: We recruited 134 children aged 2.0–5.0 years for an MRI study. We compared success between children whose parents opted for mock scanner training (n = 20) or not (n = 114), and evaluated demographic and cognitive factors that predicted success.</p><p>Results: Ninety-seven children (72%) completed at least one MRI sequence successfully on their first try; 64 children (48%) provided high-quality data for all 3 structural imaging sequences. Cognitive scores were higher in successful than unsuccessful children. Children who received mock scanner training were no more likely to be successful than children without, though they had slightly higher scores on T1 image quality.</p><p>Conclusions: Our data shows that scanning with minimial preparation is possible in young children, and suggests limited advantages of mock scanner preparation for healthy young children.Cognitive ability may predict success.</p

Factors Associated With Successful MRI Scanning in Unsedated Young Children

Introduction: Young children are often unable to remain still for magnetic resonance imaging (MRI), leading to unusable images. Various preparation methods may increase success, though it is unclear which factors best predict success. Here, in a retrospective sample, we describe factors associated with successful scanning in unsedated young children. We hypothesized that the mock scanner training and fewer behavior problems would result in higher success rates.Methods: We recruited 134 children aged 2.0–5.0 years for an MRI study. We compared success between children whose parents opted for mock scanner training (n = 20) or not (n = 114), and evaluated demographic and cognitive factors that predicted success.Results: Ninety-seven children (72%) completed at least one MRI sequence successfully on their first try; 64 children (48%) provided high-quality data for all 3 structural imaging sequences. Cognitive scores were higher in successful than unsuccessful children. Children who received mock scanner training were no more likely to be successful than children without, though they had slightly higher scores on T1 image quality.Conclusions: Our data shows that scanning with minimial preparation is possible in young children, and suggests limited advantages of mock scanner preparation for healthy young children.Cognitive ability may predict success