One effect of a maximum possible current strength Metadata

Metadata describes a digital item, providing (if known) such information as creator, publisher, contents, size, relationship to other resources, and more. Metadata may also contain "preservation" components that help us to maintain the integrity of digital files over time.


  • Main Title One effect of a maximum possible current strength


  • Author: Huang, M.
    Creator Type: Personal
  • Author: Heller, L.
    Creator Type: Personal
    Creator Info: Los Alamos National Lab., NM (United States). Biophysics Group


  • Sponsor: United States. Department of Energy.
    Contributor Type: Organization
    Contributor Info: USDOE, Washington, DC (United States)


  • Name: Los Alamos National Laboratory
    Place of Publication: New Mexico
    Additional Info: Los Alamos National Lab., NM (United States)


  • Creation: 1996-06-01


  • English


  • Content Description: One of the difficulties encountered when trying to interpret MEG/EEG experimental data is that the spatial extent of the neuronal (primary) current sources is often not known. For some classes of data it is thought that the sources are fairly well localized (focal); while for others they are expected to be distributed over a significant area or volume. In the former case, if the regions of activity are sufficiently small they can be well approximated by point current dipoles. If these are few in number there may be only one, or just a small set of acceptable solutions for the dipole parameters. At the other extreme one assumes that current is present everywhere in the source space. Even with anatomical constraints taken into account, however, this leads to a highly underdetermined problem. For example, at 1 cm resolution on the cortex it would take {approximately} 2,000 dipole moments to completely specify the current, and this is much larger than the number of measurements that can be made. Only by imposing physiological constraints can one hope to make this distributed source approach be of any use as a way to determine the actual current. This study examines the extent to which the ambiguity of a distributed source solution is reduced by imposing one specific constraint: a maximum possible value for the dipole moment per unit volume, or per unit area of cortex. There is experimental evidence in support of this limit.
  • Physical Description: 5 p.


  • Keyword: Bioelectricity
  • STI Subject Categories: 55 Biology And Medicine, Basic Studies
  • Keyword: Electrophysiology
  • Keyword: Brain
  • Keyword: Nervous System Diseases
  • Keyword: Electric Conductivity


  • Conference: Biomagnetism conference, Santa Fe, NM (United States), Feb 1996


  • Name: Office of Scientific & Technical Information Technical Reports
    Code: OSTI


  • Name: UNT Libraries Government Documents Department
    Code: UNTGD

Resource Type

  • Article


  • Text


  • Other: DE96011290
  • Report No.: LA-UR--96-1720
  • Report No.: CONF-9602101--1
  • Grant Number: W-7405-ENG-36
  • Office of Scientific & Technical Information Report Number: 244585
  • Archival Resource Key: ark:/67531/metadc668720


  • Display Note: OSTI as DE96011290