Dear Sungho,
    My student met a problem as follows when she performed result processing using sample data (Stroop). Her computer is MaC OS 64 bit. Matlab version is R2014b, Can you help us? Thank you very much!  
   Wenhai

Error using cd
Cannot CD to HbO (Name is nonexistent or not a directory).

Error in spm_fnirs_viewer_stat>push_contrast_Callback (line 136)
cd(SPM.swd);
Error in gui_mainfcn (line 95)
feval(varargin{:});
Error in spm_fnirs_viewer_stat (line 35)
gui_mainfcn(gui_State, varargin{:});
Error in
@(hObject,eventdata)spm_fnirs_viewer_stat('push_contrast_Callback',hObject,eventdata,guidata(hObject))