Development of the visual white matter pathways mediates development of electrophysiological responses in visual cortex

Hum Brain Mapp. 2021 Dec 1;42(17):5785-5797. doi: 10.1002/hbm.25654. Epub 2021 Sep 6.


The latency of neural responses in the visual cortex changes systematically across the lifespan. Here, we test the hypothesis that development of visual white matter pathways mediates maturational changes in the latency of visual signals. Thirty-eight children participated in a cross-sectional study including diffusion magnetic resonance imaging (MRI) and magnetoencephalography (MEG) sessions. During the MEG acquisition, participants performed a lexical decision and a fixation task on words presented at varying levels of contrast and noise. For all stimuli and tasks, early evoked fields were observed around 100 ms after stimulus onset (M100), with slower and lower amplitude responses for low as compared to high contrast stimuli. The optic radiations and optic tracts were identified in each individual's brain based on diffusion MRI tractography. The diffusion properties of the optic radiations predicted M100 responses, especially for high contrast stimuli. Higher optic radiation fractional anisotropy (FA) values were associated with faster and larger M100 responses. Over this developmental window, the M100 responses to high contrast stimuli became faster with age and the optic radiation FA mediated this effect. These findings suggest that the maturation of the optic radiations over childhood accounts for individual variations observed in the developmental trajectory of visual cortex responses.

Keywords: MEG; childhood; diffusion MRI; tractography; visual system.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Child
  • Cross-Sectional Studies
  • Diffusion Tensor Imaging*
  • Evoked Potentials / physiology*
  • Female
  • Humans
  • Magnetoencephalography*
  • Male
  • Visual Cortex / anatomy & histology
  • Visual Cortex / diagnostic imaging
  • Visual Cortex / growth & development*
  • Visual Pathways / anatomy & histology
  • Visual Pathways / diagnostic imaging
  • Visual Pathways / growth & development*
  • White Matter / anatomy & histology
  • White Matter / diagnostic imaging
  • White Matter / growth & development*