PsychToolboxhas resisted the upgrade to a 64-bit codebase for some time. The recent 3.0.9 update introduces 64-bit support on Linux only, and Mario Kleiner promises that in this version,

[…] the extra bits provide you with 50% higher effect sizes, higher d’ and greater levels of significance with less subjects, whatever you’re measuring.

Well maybe not, but it’s nice to see my favorite OS being treated with respect.

It’s not exactly trivial to get PTB to work in Linux. After using the DownloadPsychtoolbox script, I ran into several errors that were fixed through the judicious application of sudo apt-get. I can’t remember all I did to get it working, though I remember having installed subversion, libglut3 and rhythmbox (for GStreamer support). libraw1394 was a little more tricky, as my version of Ubuntu (Natty) has version 11 while Psychtoolbox Matlab seems to need version 8. I had to add the main repository from Hardy, the last version of Ubuntu to have the 8 version, and then install the libraw1394-8 This can be addressed by removing libdc1394 from Matlab’s installation folder, which enforces the use of the outdated libraw1394 library (thanks to Mario Kleiner and Geoff for the info).

I found that I couldn’t address each screen in my dual screen setup individually — using Screen(‘OpenWindow’,1), for example — so I sent an email on the mailing list and received a quick reply from Mario saying that this is due to the selection of the TwinView display mode in the NVidia screen configuration, while separate X screens should be used. More info on the mailing list.