How age of bilingual exposure can change the neural systems for language in the developing brain: A functional near infrared spectroscopy investigation of syntactic processing in monolingual and bilingual children

AbstractIs the developing bilingual brain fundamentally similar to the monolingual brain (e.g., neural resources supporting language and cognition)? Or, does early-life bilingual language experience change the brain? If so, how does age of first bilingual exposure impact neural activation for language?We compared how typically-developing bilingual and monolingual children (ages 7–10) and adults recruit brain areas during sentence processing using functional Near Infrared Spectroscopy (fNIRS) brain imaging. Bilingual participants included early-exposed (bilingual exposure from birth) and later-exposed individuals (bilingual exposure between ages 4–6).Both bilingual children and adults showed greater neural activation in left-hemisphere classic language areas, and additionally, right-hemisphere homologues (Right Superior Temporal Gyrus, Right Inferior Frontal Gyrus). However, important differences were observed between early-exposed and later-exposed bilinguals in their earliest-exposed language. Early bilingual exposure imparts fundamental changes to classic language areas instead of alterations to brain regions governing higher cognitive executive functions. However, age of first bilingual exposure does matter. Later-exposed bilinguals showed greater recruitment of the prefrontal cortex relative to early-exposed bilinguals and monolinguals.The findings provide fascinating insight into the neural resources that facilitate bilingual language use and are discussed in terms of how early-life language experiences can modify the neural systems underlying human language processing

Bilingualism alters children’s frontal lobe functioning for attentional control

Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on children’s cognitive and brain development. Theories of bilingualism suggest that early dualâ language acquisition can improve children’s cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on children’s frontal lobe development. Using functional nearâ infrared spectroscopy (fNIRS), the findings suggest that Spanishâ English bilingual children (n = 13, ages 7â 13) had greater activation in left prefrontal cortex during a nonâ verbal attentional control task relative to ageâ matched English monolinguals. In contrast, monolinguals (n = 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of children’s prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.This fNIRS study investigated the impact of bilingual exposure on children’s brain organization for attentional control (N = 27, ages 7â 13). During a nonâ verbal attention task, bilinguals showed greater left frontal lobe activation than monolinguals. Monolinguals showed greater right frontal lobe activation than bilinguals. The findings suggest that bilingualism affects the functionality of children’s left prefrontal cortex for attentional control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/1/desc12377-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/2/desc12377.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/3/desc12377_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/4/desc12377-sup-0003-SupInfo.pd

Anatomical Substrates of Visual and Auditory Miniature Second-language Learning

Contains fulltext : 56945.pdf (publisher's version ) (Open Access)Longitudinal changes in brain activity during second language (L2) acquisition of a miniature finite-state grammar, named Wernickese, were identified with functional magnetic resonance imaging (fMRI). Participants learned either a visual sign language form or an auditory-verbal form to equivalent proficiency levels. Brain activity during sentence comprehension while hearing/viewing stimuli was assessed at low, medium, and high levels of proficiency in three separate fMRI sessions. Activation in the left inferior frontal gyrus (Broca's area) correlated positively with improving L2 proficiency, whereas activity in the right-hemisphere (RH) homologue was negatively correlated for both auditory and visual forms of the language. Activity in sequence learning areas including the premotor cortex and putamen also correlated with L2 proficiency. Modality-specific differences in the blood oxygenation level-dependent signal accompanying L2 acquisition were localized to the planum temporale (PT). Participants learning the auditory form exhibited decreasing reliance on bilateral PT sites across sessions. In the visual form, bilateral PT sites increased in activity between Session 1 and Session 2, then decreased in left PT activity from Session 2 to Session 3. Comparison of L2 laterality (as compared to L1 laterality) in auditory and visual groups failed to demonstrate greater RH lateralization for the visual versus auditory L2. These data establish a common role for Broca's area in language acquisition irrespective of the perceptual form of the language and suggest that L2s are processed similar to first languages even when learned after the 'critical period'. The right frontal cortex was not preferentially recruited by visual language after accounting for phonetic/structural complexity and performance.14 p

Normal-tension glaucomatous optic neuropathy is related to blood pressure variability in the Maracaibo Aging Study

Hypoperfusion of the optic nerve might be involved in the pathogenesis of normal-tension glaucomatous optic neuropathy (GON). Mean arterial pressure (MAP) drives ocular perfusion, but no previous studies have addressed the risk of GON in relation to blood pressure (BP) variability, independent of BP level. In a cross-sectional study, 93 residents of Maracaibo, Venezuela, underwent optical coherence tomography, visual field assessments and 24-h ambulatory BP monitoring between 2011 and 2016. We investigated the association of normal-tension GON with or without visual field defects with reading-to reading variability of 24-h MAP, as captured by variability independent of the MAP level (VIMmap). Odds ratios (ORs) were adjusted for 24-h MAP level and for a propensity score of up to five risk factors. Among the 93 participants (87.1% women; mean age, 61.9 years), 26 had open-angle normal-tension GON at both eyes; 14 had visual field defects; and 19 did not have visual field defects. The OR ratios for normal-tension GON, expressed per 1-SD increment in VIMmap (2 mm Hg), were 2.17 (95% confidence interval, 1.33-3.53) unadjusted; 2.20 (1.35-3.61) adjusted for 24-h MAP level only; 1.93 (1.10-3.41) with additional adjustment for age, educational attainment, high-density lipoprotein (HDL) cholesterol and office hypertension; and 1.95 (1.10-3.45) in models including intraocular pressure. We confirmed our a priori hypothesis that BP variability, most likely operating via hypoperfusion of the optic nerve, is associated with normal-tension GON. 24-H ambulatory BP monitoring might therefore help stratify the risk of normal-tension GON