The present study examined the characteristics of somatosensory processing in healthy prepubescent children (mean age: 124.9 ± 3.8 months) compared with young adults. Somatosensory evoked potentials at the frontal (Fz) and centroparietal (C3′) electrodes were recorded by delivering an electrical stimulus to the right median nerve at a rate of 3 Hz. The characteristics of somatosensory evoked potential waveforms at C3′ were markedly different between the two groups, while those at Fz were similar. Specifically, the waveforms at C3′ in the children involved not only standard P12, N18, P22, N27, P45, and N60 components, but also additional positive (P3) and negative (N3) components between N27 and P45, which were not found in adults. The amplitude of P22 at C3′ was significantly larger in the children than adults, indicating hyper-excitability/responsiveness of neural activity on somatosensory processing. In contrast, the amplitudes of N15 at Fz and N27 at C3′ were smaller in the children than adults, suggesting an immature somatosensory system in the children. The peak latencies of P12, N15, and P18 at Fz, and P12 and N18 at C3′ were significantly shorter in the children than adults, which was dependent on the height. These results indicate the developing somatosensory processing with hyper- and hypo-excitability of neural activity in prepubescent children.
aThe Elementary School Attached to Nara Women's University, Nara
bFaculty of Engineering, Information, and Systems, University of Tsukuba, Tsukuba
cGraduate School of Arts and Sciences, The University of Tokyo, Tokyo
dDepartment of Health Sciences, Faculty of Human Life and Environment, Nara Women's University, Nara, Japan
Received 1 July 2019 Accepted 12 September 2019
Correspondence to Hiroki Nakata, Department of Health Sciences, Faculty of Human Life and Environment, Nara Women's University, Kitauoya-Nishi Machi, Nara, 630-8506, Japan, Tel: +81 742 20 3345; fax: +81 742 20 3345; e-mail: email@example.com