(AAP) recommends limits on screen-based media use, citing its cognitive-behavioral risks. Screen use by young children is prevalent and increasing, although its implications for brain development are unknown. OBJECTIVE To explore the associations between screen-based media use and integrity of brain white matter tracts supporting language and literacy skills in preschool-aged children. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study of healthy children aged 3 to 5 years (n = 47) was conducted from August 2017 to November 2018. Participants were recruited at a US children's hospital and community primary care clinics. EXPOSURES Children completed cognitive testing followed by diffusion tensor imaging (DTI), and their parent completed a ScreenQ survey. MAIN OUTCOMES AND MEASURES ScreenQ is a 15-item measure of screen-based media use reflecting the domains in the AAP recommendations: access to screens, frequency of use, content viewed, and coviewing. Higher scores reflect greater use. ScreenQ scores were applied as the independent variable in 3 multiple linear regression models, with scores in 3 standardized assessments as the dependent variable, controlling for child age and household income: Comprehensive Test of Phonological Processing, Second Edition (CTOPP-2; Rapid Object Naming subtest); Expressive Vocabulary Test, Second Edition (EVT-2; expressive language); and Get Ready to Read! (GRTR; emergent literacy skills). The DTI measures included fractional anisotropy (FA) and radial diffusivity (RD), which estimated microstructural organization and myelination of white matter tracts. ScreenQ was applied as a factor associated with FA and RD in whole-brain regression analyses, which were then narrowed to 3 left-sided tracts supporting language and emergent literacy abilities. RESULTS Of the 69 children recruited, 47 (among whom 27 [57%] were girls, and the mean [SD] age was 54.3 [7.5] months) completed DTI. Mean (SD; range) ScreenQ score was 8.6 (4.8; 1-19) points. Mean (SD; range) CTOPP-2 score was 9.4 (3.3; 2-15) points, EVT-2 score was 113.1 (16.6; 88-144) points, and GRTR score was 19.0 (5.9; 5-25) points. ScreenQ scores were negatively correlated with EVT-2 (F 2,43 = 5.14; R 2 = 0.19; P < .01), CTOPP-2 (F 2,35 = 6.64; R 2 = 0.28; P < .01), and GRTR (F 2,44 = 17.08; R 2 = 0.44; P < .01) scores, controlling for child age. Higher ScreenQ scores were correlated with lower FA and higher RD in tracts involved with language, executive function, and emergent literacy abilities (P < .05, familywise error-corrected), controlling for child age and household income. CONCLUSIONS AND RELEVANCE This study found an association between increased screen-based media use, compared with the AAP guidelines, and lower microstructural integrity of brain white matter tracts supporting language and emergent literacy skills in prekindergarten children. The findings suggest further study is needed, particularly during the rapid early stages of brain development.

BACKGROUND AND OBJECTIVES: Parent-child reading is widely advocated to promote cognitive development, including in recommendations from the American Academy of Pediatrics to begin this practice at birth. Although parent-child reading has been shown in behavioral studies to improve oral language and print concepts, quantifiable effects on the brain have not been previously studied. Our study used blood oxygen level-dependent functional magnetic resonance imaging to examine the relationship between home reading environment and brain activity during a story listening task in a sample of preschool-age children. We hypothesized that while listening to stories, children with greater home reading exposure would exhibit higher activation of left-sided brain regions involved with semantic processing (extraction of meaning).METHODS: Nineteen 3-to 5-year-old children were selected from a longitudinal study of normal brain development. All completed blood oxygen level-dependent functional magnetic resonance imaging using an age-appropriate story listening task, where narrative alternated with tones. We performed a series of whole-brain regression analyses applying composite, subscale, and individual reading-related items from the validated StimQ-P measure of home cognitive environment as explanatory variables for neural activation.RESULTS: Higher reading exposure (StimQ-P Reading subscale score) was positively correlated (P , .05, corrected) with neural activation in the left-sided parietal-temporal-occipital association cortex, a "hub" region supporting semantic language processing, controlling for household income. CONCLUSIONS:In preschool children listening to stories, greater home reading exposure is positively associated with activation of brain areas supporting mental imagery and narrative comprehension, controlling for household income. These neural biomarkers may help inform eco-bio-developmental models of emergent literacy. WHAT'S KNOWN ON THIS SUBJECT:The American Academy of Pediatrics recommends parent-child reading from infancy through at least kindergarten, the span of maximal brain growth. Home literacy environment, including reading behaviors and access to books, has been shown to promote oral language and print concepts. WHAT THIS STUDY ADDS:Home reading environment is positively associated with activation of brain areas supporting narrative comprehension and mental imagery in preschool children. This offers novel insight into the neurobiological foundations of emergent literacy and potential effect of shared reading during early childhood. Dr Hutton conceptualized and designed the study, performed all data analysis, and drafted the initial manuscript and subsequent revisions; Dr Horowitz-Kraus provided guidance on study design and analysis, assisted with coordination of data collection, and reviewed and revised the manuscript; Dr Mendelsohn served as national outside facilitator and mentor for this project, provided advice on the use of the StimQ measure, and reviewed and revised the manuscript; Dr...

Poor reading skills of developmental dyslexics persist into adulthood with standard remediation protocols having little effect. Nevertheless, reading improves if readers are induced to read faster. Here we show that this improvement can be enhanced by training. Training follows a multi-session procedure adapted to silent sentence reading, with individually set, increasingly more demanding, time constraints (letter-by-letter masking). In both typical and dyslexic adult readers, reading times are shortened and comprehension improves. After training, the dyslexic readers' performance is similar to that of typical readers; moreover, their connected text reading times and comprehension scores significantly improve in standard reading tests and are retained at 6 months post training. Identical training without time constraints proves ineffective. Our results suggest that fluent reading depends in part on rapid information processing, which then might affect perception, cognitive processing and possibly eye movements. These processes remain malleable in adulthood, even in individuals with developmental dyslexia.