Contrasts STEP BY STEP

The use of contrasts can be automated in BrainVoyager QX via the steps shown below.

 

 

Via scripting

Via the BrainVoyager user interface

 

1. Create a BrainVoyager document variable with OpenDocument() or ActiveDocument(). The ActiveDocument() method returns a document that is present in the BrainVoyager main window.

 

 

 

2. A *.glm file can be loaded with the command LoadGLM().

 

 

 

3. Clear the current contrast values with the method ClearContrasts().

 

 

 

 

4. Insert a new contrast via AddContrast().

 

 

 

 

5. Next, a contrast value can be set in different ways.

 

Via SetContrastValue(), this requires a predictor name and a positive or negative value:

"LVF", +1

 

Or via the method SetContrastString(); this method expects a string with values for all predictors:

"1 -1 0 0".

 

Also available is the method

SetContrastValueAtIndex(). The index number of the predictor should be provided and a positive or negative value. The numbering of the predictors starts with 1:

1, +1

 

 

 

 

 

 

6. Show the contrasts via ShowGLM().