Format

Send to

Choose Destination
See comment in PubMed Commons below

The spatial location of EEG electrodes: locating the best-fitting sphere relative to cortical anatomy.

Author information

1
Department of Neurology, University of Chicago, IL 60637.

Abstract

The location of the international 10-20 system electrode positions and 14 fiducial landmarks are described in cartesian coordinates (+/- 1.4 mm average accuracy). Six replications were obtained on 3 separate days from 4 normal subjects, who were compared to each other with a best-fit sphere algorithm. Test-retest reliability depended on the electrode position: the parasagittal electrodes were associated with greater measurement errors (maximum 7 mm) than midline locations. Location variability due to head shape was greatest in the temporal region, averaging 5 mm from the mean. For each subject's electrode locations a best-fitting sphere was determined (79-87 mm radius, 6% average error). A surface-fitting algorithm was used to transfer the electrode locations and best-fitting sphere to MR images of the brain and scalp. The center of the best-fitting sphere coincided with the floor of the third ventricle 5 mm anterior to the posterior commissure. The melding of EEG electrode location information with brain anatomy provides an empirical basis for associating hypothetical equivalent dipole locations with their anatomical substrates.

PMID:
7678386
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center