GLM : individual level
 Image time-series
                     Spatial filter       Design matrix        Statistical Parametric Map
   Realignment        Smoothing         General Linear Model
                                                                  Statistical        RFT
          Normalisation                                           Inference
                         Anatomical                                             p <0.05
                         reference Parameter estimates
     GLM : individual level
              1                      p                        1
                                                                   y X 
                                                1
           y =            X            p         + 
                                                                   Error Covariance
                                                                C   k Q
                                                                                    k
    N           N                                  N                       k
                                                           Model is specified by
                                                           Model is specified by
                                                           1.  Design matrix X
         N: number of scans                                1.   Design matrix X
         N: number of scans                                2.  Assumptions about 
         p: number of regressors                           2.   Assumptions about 
         p: number of regressors
                                                               e
                                                                e
      GLM : Several individuals
                                                                         SPM(t)
            Data              Design Matrix    Contrast Images
                            ˆ
                           
                            1
                           ˆ2
                          1
                            ˆ
                           2
                           ˆ2
                           2
                           ˆ
                          
                            11
                            ˆ2
                           11
                            ˆ
                           
                             12
                            ˆ2
                           12
  Fixed effect
                     ˆ
                    
                      1
                     ˆ2
                    1                                                                               SPM(t)
                                                             subj. 1
                     ˆ
                    2
                     ˆ2
                    2
                     ˆ                                       subj. 2
                    
                      11
                     ˆ2
                    11
                     ˆ
                    
                      12                                     subj. 3
                     ˆ2
                    12
                           Grand GLM approach
                               (model all subjects at 
                               once)
 Fixed effect
   Fixed effect modelling in SPM
  Grand GLM approach
    (model all subjects at once)
                                          subj. 1
  Good:                                  subj. 2
      max dof
      simple model
                                          subj. 3