Elektra Beckum NM20600A-A, MCE manual Selecting the head model, BEM selection

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Selecting the head model

MCE User’s Guide

4 Selecting the head model

You can select the head model by pressing the [Head model] button in the Main window (p. 22). The head model consists of two parts: the boundary element model (BEM) (p. 8) describes the shape of the brain and the point set (p. 9) describes the parameters needed in the calculation. First, the BEM model selection window opens up.

4.1 BEM selection

Figure 5 BEM model selection dialog

The boundary element model (BEM) describes the shape of the brain. In the cur- rent version (1.3), only sphere models are used in the forward calculation, but the BEM model affects the point set used in the calculation and the images used in the 3D visualization.

The BEM dialog shows a list of existing models associated with the same subject and some general models. You can select an existing model from the list and accept it by pressing the [OK] button.

You can add a new BEM model by pressing the [Add new] button. A file selection box for selecting the fif-file opens up, and after the selection you can select the associated the subject.

If the BEM model is not used by any point set (p. 9), you can delete it by pressing the [Delete] button. If it is used by point sets, you should first delete the point sets.

After you have accepted the BEM model by pressing the [OK] button, you should select the point set.

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2004-05-17

NM20600A-A

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Contents MCE User’s Guide Copyright and Warranty Contents Index Introduction Hazard InformationVersion What’s new?Conventions and typography ReferencesGetting Started Analyzing dataQuitting the program Setting the filtering and baselines Selecting the data file and pre-processingDecreasing the computing time and file sizes Effect of the baselinesBad channels and projections MCE User’s Guide Selecting the head model BEM selectionPoint set selection Point set selection dialogCreating BEM files Min distCalculating the estimates Loading a calculated estimate Selecting the time What is ROI? What is the orientation of a ROI?Region of interest Selecting a ROI ROI databaseExporting ROIs Predicting MEG waveforms Printing Printing from the dialogSaving to an image file Saving with xgifdump command Creating Html documents and Mpeg movies Creating Html documentsCreating movies MCE windows and dialogs Window menusMain window Options menuPre-processing dialog Minimum norm estimate options dialogPre-processing dialog Units Hz MEG data dialog Remove meanFull calculation dialog Select fileBatch jobs window CalculationColor display Color display of the estimateArrow display Arrow display of the estimateAmplitude window Amplitude window with total activityAmplitude scale window Amplitude scale windowConstant color mode Relative color modeColor scale window Things to remember Region of interest windowROI database window ROI databaseROI search ROI listCurrent ROI Other controlsSQL database Html Creation Dialog Html Creation DialogMovie Creation Dialog Time periodsWindow length Index MCE User’s Guide