Neuromagnetic biomarkers of visuocortical development in healthy children

ObjectiveThe objective of the present study was to investigate noninvasive biomarkers for visuocortical development in healthy children.MethodsSixty healthy children and 20 adults were studied with a whole-head magnetoencephalography (MEG) system. The adults were included to find out when the markers stabilize. Visual evoked magnetic fields (VEFs) were evoked with full-field pattern-reversal checks.ResultsThree response peaks were identified at 77 ± 8 ms (M75), 111 ± 9 ms (M100) and 150 ± 11 ms (M145) for children. The latency of M75 and M100 decreased with age (p < 0.01). The amplitude ratio of M100/M75 increased significantly with age (p < 0.001). The differences of MEG source images between the left and right occipital cortices for M75 and M145 increased significantly with age (r = 0.47 and 0.46, respectively, p < 0.01).ConclusionsThe latency of M75 and M100 and the amplitude ratio of M100/M75 are robust biomarkers for the development of visual function in children.SignificanceThe development of visual function in childhood is noninvasively measurable. The results lay a foundation for quantitative identification of developmental delay and/or abnormalities of visual function in children with brain disorders.