Efficient neuromagnetic determination of landmarks in the somatosensory cortex

Clin Neurophysiol. 2000 Aug;111(8):1478-87. doi: 10.1016/s1388-2457(00)00349-7.

Abstract

Objectives: An efficient procedure for the magnetoencephalographic determination of functional landmarks in the somatosensory cortex has been developed.

Methods: Digits 2-5 are stimulated in randomized order using balloon diaphragms. The interval between two stimuli is 500 ms. Source locations in area 3b are derived by interpreting the field component with a mean latency of 48 ms in terms of an equivalent current dipole.

Results: The signal-to-noise ratio achieved in a given time for each of the 4 stimulation sites turned out to be only slightly smaller than the one obtained by stimulating a single site with an optimal interstimulus interval (about 1 s).

Conclusions: Compared to a sequential investigation of the different sites, the proposed procedure allows the reduction of the overall measurement time by a factor of about 2.7.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain Mapping
  • Electric Stimulation
  • Humans
  • Magnetics*
  • Physical Stimulation
  • Somatosensory Cortex / physiology*
  • Time Factors