/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/ is in psychtoolbox-3-common 3.0.11.20131230.dfsg1-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/BSRuntimeLibs/
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/BSRuntimeLibs/Contents.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/BrightSideCore.cpp
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/BrightSideCore.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/BrightSideHDR.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/Contents.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/HDRMinimalisticOpenGLDemo.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/HDRRead.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/HDRViewer.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/ShowHDRDemo.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/SimpleHDRDemo.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/SimpleHDROfflineCaptureTest.m
/usr/share/psychtoolbox-3/PsychHardware/BrightSideDisplay/mexopts.bat_for_MPI_HDR_On_Matlab72