Integrated approach for studying adaptation mechanisms in the human somatosensory cortical network

Exp Brain Res. 2014 Nov;232(11):3545-54. doi: 10.1007/s00221-014-4043-5. Epub 2014 Jul 25.

Abstract

Magnetoencephalography and independent component analysis (ICA) was utilized to study and characterize neural adaptation in the somatosensory cortical network. Repetitive punctate tactile stimuli were applied unilaterally to the dominant hand and face using a custom-built pneumatic stimulator called the TAC-Cell. ICA-based source estimation from the evoked neuromagnetic responses indicated cortical activity in the contralateral primary somatosensory cortex (SI) for face stimulation, while hand stimulation resulted in robust contralateral SI and posterior parietal cortex (PPC) activation. Activity was also observed in the secondary somatosensory cortical area (SII) with reduced amplitude and higher variability across subjects. There was a significant difference in adaptation rate between SI and higher-order somatosensory cortices for hand stimulation. Adaptation was significantly dependent on stimulus frequency and pulse index within the stimulus train for both hand and face stimulation. The peak latency of the activity was significantly dependent on stimulation site (hand vs. face) and cortical area (SI vs. PPC). The difference in the peak latency of activity in SI and PPC is presumed to reflect a hierarchical serial-processing mechanism in the somatosensory cortex.

Publication types

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

MeSH terms

  • Adaptation, Physiological / physiology*
  • Adult
  • Analysis of Variance
  • Brain Mapping*
  • Electroencephalography
  • Evoked Potentials, Somatosensory / physiology*
  • Face / innervation
  • Female
  • Hand / innervation
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Magnetoencephalography
  • Physical Stimulation / instrumentation
  • Physical Stimulation / methods
  • Reaction Time / physiology
  • Somatosensory Cortex / physiology*
  • Young Adult