As soon as the (averaged) anatomy, VTC and SDM (RTC in older versions) files have been created, you're able to run a Multi Study GLM. First, open the Multi-Study (MS) GLM dialog from the Analysis tab. **Building a second-level design matrix **

Multi study design matrices are constructed from a set of single study design matrices. Therefore, you must first specify the single-study design matrices of all studies which you want to include in the multi study analysis. A multi study GLM analysis is defined by simply referring to time course data files (e.g. FMRs or VTCs) and associated single study design matrix files (SDMs). From this information, a proper multi study design matrix file is automatically constructed as described below. BrainVoyager offers three ways to construct a multi study design matrix from a series of single-study design matrices:

- one set of predictors across all studies (concatenation of predictors, Fixed Effects Analysis)
- creation of a separate set of predictors for each study
- creation of a separate set of predictors for each subject (needed for a Random Effects Analysis)

**Experiment description **

To explain the details of the creation of multi study design matrices, we will use the slow event related "Mental Clock task" experiment with three predictors. During the Auditory Stimulation condition subjects were told two different times (e.g. two o'clock and five o'clock). During the Imagery condition they had to imagine these times on an analog clock and should compare the angles between the long and short arm of the clock. During the Response phase they had to indicate whether the first or second angle was greater.