Age-related changes across the primary and secondary somatosensory areas: An analysis of neuromagnetic oscillatory activities

Koichi Hagiwara, Katsuya Ogata, Tsuyoshi Okamoto, Taira Uehara, Naruhito Hironaga, Hiroshi Shigeto, Jun ichi Kira, Shozo Tobimatsu

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


Objective: Age-related changes are well documented in the primary somatosensory cortex (SI). Based on previous somatosensory evoked potential studies, the amplitude of N20 typically increases with age probably due to cortical disinhibition. However, less is known about age-related change in the secondary somatosensory cortex (SII). The current study quantified age-related changes across SI and SII mainly based on oscillatory activity indices measured with magnetoencephalography. Methods: We recorded somatosensory evoked magnetic fields (SEFs) to right median nerve stimulation in healthy young and old subjects and assessed major SEF components. Then, we evaluated the phase-locking factor (PLF) for local field synchrony on neural oscillations and the weighted phase-lag index (wPLI) for cortico-cortical synchrony between SI and SII. Results: PLF was significantly increased in SI along with the increased amplitude of N20m in the old subjects. PLF was also increased in SII associated with a shortened peak latency of SEFs. wPLI analysis revealed the increased coherent activity between SI and SII. Conclusions: Our results suggest that the functional coupling between SI and SII is influenced by the cortical disinhibition due to normal aging. Significance: We provide the first electrophysiological evidence for age-related changes in oscillatory neural activities across the somatosensory areas.

Original languageEnglish
Pages (from-to)1021-1029
Number of pages9
JournalClinical Neurophysiology
Issue number5
Publication statusPublished - May 2014

All Science Journal Classification (ASJC) codes

  • Sensory Systems
  • Neurology
  • Clinical Neurology
  • Physiology (medical)


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