Hi, I have extracted the values from a seed voxel for three separate groups (the same voxel for all groups). Each group then has a group voxel data file. I'm now trying to look for differences in connectivity in these three groups. To do this I'm appending the three group voxel data files into one voxel data file and loading this single file as a behavioural file in a Regular Behavioural PLS analysis, so that the behavioural file is in the format: Group1_Cond1_Subject1... Group1_Cond1_Subject43... Group1_Cond5_Subject1... Group1_Cond5_Subject43... Group2_Cond1_Subject1... Group2_Cond1_Subject48... Group2_Cond5_Subject1... Group2_Cond5_Subject48... Group3_Cond1_Subject1... Group3_Cond1_Subject47... Group3_Cond5_Subject1... Group3_Cond5_Subject47... I'm getting the following error message: "??? Error using ==> bfm_analysis_ui('RUN BUTTON PRESSED'); No right hand side assignment. ??? No right hand side value for assignment" This problem isn't with the individual behavioural files, because if I do separate seed PLS analyses on each group with their respective behavioural files the analysis runs fine. The problem must be with the appending. Any suggestions? Many thanks in advance, Dan.