/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/ is in psychtoolbox-3-common 3.0.11.20140816.dfsg1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655close.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655config.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655getsyncfreq.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655init.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655measspd.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655measxyz.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655parsespdstr.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655rawspd.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655rawxyz.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655read.m
/usr/share/psychtoolbox-3/PsychHardware/PR655Toolbox/PR655write.m