Cited by 112Hemispheric Asymmetry in NeuroscienceFunctional Brain Connectivity StudiesNeurobiology of Language and Bilingualism

Longitudinal Study of the Emerging Functional Connectivity Asymmetry of Primary Language Regions during Infancy

Open access
Emerson, Robert W., Gao, Wei, Lin, Weili·2016·The Journal of Neuroscience

Abstract

Asymmetry in the form of left-hemisphere lateralization is a striking characteristic of the cerebral regions involved in the adult language network. In this study, we leverage a large sample of typically developing human infants with longitudinal resting-state functional magnetic resonance imaging scans to delineate the trajectory of interhemispheric functional asymmetry in language-related regions during the first 2 years of life. We derived the trajectory of interhemispheric functional symmetry of the inferior frontal gyrus (IFG) and superior temporal gyrus (STG), the sensory and visual cortices, and two higher-order regions within the intraparietal sulcus and dorsolateral prefrontal cortex. Longitudinal models revealed a best fit with quadratic age terms and showed significant estimated coefficients of determination for both the IFG (r2= 0.261,p< 0.001) and the STG (r2= 0.142,p< 0.001) regions while all other regions were best modeled by log-linear increases. These inverse-U-shaped functions of the language regions peaked at ∼11.5 months of age, indicating that a transition toward asymmetry began in the second year. This shift was accompanied by an increase in the functional connectivity of these regions within the left hemisphere. Finally, we detected an association between the trajectory of the IFG and language outcomes at 4 years of age (χ 2= 10.986,p= 0.011). Our results capture the developmental timeline of the transition toward interhemispheric functional asymmetry during the first 2 years of life. More generally, our findings suggest that increasing interhemispheric functional symmetry in the first year might be a general principle of the developing brain, governing different functional systems, including those that will eventually become lateralized in adulthood. SIGNIFICANCE STATEMENT Cross-sectional studies of the language system in early infancy suggest that the basic neural mechanisms are in place even before birth. This study represents the first of its kind, using a large longitudinal sample of infants, to delineate the early language-related transition toward interhemispheric functional asymmetry in the brain using resting-state functional MRI. More generally, our findings suggest that increasing interhemispheric functional symmetry in the first year might be a general principle of the developing brain governing multiple functional systems, including those that will eventually become lateralized in adulthood. Although resting-state functional MRI cannot provide direct insights into the developmental mechanisms of language lateralization, this study reveals language-related functional connectivity changes during infancy, marking critical points in the development of the brain's functional architecture.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1523/jneurosci.3980-15.2016

Cites

61 of 61 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • The default-mode network shows the earliest synchronization of its constituent regions and achieves an adult-like core structure by around six months, consistent with the emergence of self-awareness thought to depend on this network at that age.

    “the default-mode network99, 100 shows the earliest synchronization of its constituent regions and achieves an adult-like core structure [G] by around 6 months of age91, consistent with the emergence of self-awareness, which is thought to depend on the default-mode network, at this age101.”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Emerson, R. W., Gao, W., & Lin, W.
Affiliations
  • University of North Carolina at Chapel Hill (US)
  • Cedars-Sinai Medical Center (US)
Venue
The Journal of Neuroscience
Published
2016-10-19
Volume
36
Issue
42
Pages
10883-10892
ISSN
  • 0270-6474 (ISSN-L)
  • 1529-2401
OpenAlex
W2533920203
Cited by
112
References
61
Citations by year
2026: 5 · 2025: 13 · 2024: 10 · 2023: 9 · 2022: 7 · 2021: 7 · 2020: 44 · 2019: 4 · 2018: 10 · 2017: 3
FWCI
3.60
Type
journal article
Language
en
Open access
Locations
  • Journal of Neuroscience (publishedVersion, cc-by-nc-sa)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • Carolina Digital Repository (University of North Carolina at Chapel Hill) (submittedVersion)
  • UNC Libraries
Funders
  • Cedars-Sinai Medical Center
  • National Institutes of Health
  • National Institute of Mental Health (U01MH110274)
  • National Institute of Neurological Disorders and Stroke (R21NS088975)
  • Eunice Kennedy Shriver National Institute of Child Health and Human Development (T32HD040127)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Hemispheric Asymmetry in Neuroscience
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Functional Brain Connectivity Studies
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Neurobiology of Language and Bilingualism
Keywords
language lateralization, infancy, resting-state functional connectivity, inferior frontal gyrus, superior temporal gyrus, intraparietal sulcus, dorsolateral prefrontal cortex, brain development, language outcomes, hemispheric lateralization, typically developing infants
MeSH terms
Child Development, Cognition, Female, Humans, Image Processing, Computer-Assisted, Infant, Infant, Newborn, Language Development, Functional Laterality, Longitudinal Studies, Magnetic Resonance Imaging, Male, Nerve Net, Neural Pathways, Somatosensory Cortex, Temporal Lobe, Visual Cortex, Prefrontal Cortex

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review