ECD analysis treats localization as an inverse problem: researchers begin with measured electric or magnetic fields and search for dipole parameters that fit those observations. Position indicates the estimated source location, orientation describes its direction, and strength represents the modeled source magnitude. The resulting fit links recorded signals to a candidate neural generator.
An ECD simplifies neural activity into a localized source, so its result depends on how well that representation matches the underlying activity and measurement conditions. Different assumptions about the source or the recorded fields can influence the fitted parameters. Consequently, an estimated location should be interpreted as model-based evidence rather than an unrestricted measurement of anatomy.
EEG and MEG provide different measured fields for the same general modeling strategy. ECD analysis can use either electrical signals from electroencephalography or magnetic signals from magnetoencephalography, then fit dipole parameters to the observations. The measurement type therefore determines which recorded field is modeled, while the localization framework remains centered on estimating the neural source.
A typical workflow begins by collecting EEG or MEG measurements during a neural event, identifying the signal of interest, and fitting a dipole model to the observed fields. The analysis estimates position, orientation, and strength, after which researchers examine whether the fit provides a plausible account of the recorded activity. Measurement quality and model assumptions influence the outcome.
Researchers may apply this approach when they need to estimate where activity associated with a particular neural event arises. Supported examples include sensory processing, seizures, and other neural events recorded with EEG or MEG. Its value lies in providing a source-localization estimate that can help relate measured signals to the organization of brain function.
The fitted parameters provide an estimate of the event’s source location, directional orientation, and modeled strength. These outputs can help researchers compare neural activity with sensory processing, seizure-related activity, or other events. Interpretation remains conditional on the quality of the electrical or magnetic measurements and on whether the simplified dipole model adequately represents the activity.