Psychtoolbox interfaces between Matlab or Octave and the computer hardware. The PTB core routines provide access to the display frame buffer and color lookup table, reliably synchronize with the vertical screen retrace, support sub-millisecond timing, expose raw OpenGL commands, support video playback and capture as well as low-latency audio, and facilitate the collection of observer responses. Ancillary routines support common needs like color space transformations and the QUEST threshold seeking algorithm.

Psychtoolbox has many active users, an active forum, and is widely cited. PTB-3 is based on the deprecated Psychophysics Toolbox Version 2 with its Matlab C extensions rewritten to be more modular and to use OpenGL on the back end. The current version supports at least Matlab R2021b, and Octave 5 and later on Linux, and Octave 6.4 on macOS, and Windows.

Psychtoolbox News

Psychtoolbox beta updated


Psychtoolbox 3.0.18 Beta update “Experimental Taylor expansion “ SP5 was released at 22nd May 2022. As usual, the complete development history can be found in our GitHub repository. The release tag is “”, with the full tree and commit logs under the URL:

A minor update for macOS Octave compatibility, help/status text updates and to mention our new user survey.


  • Reword text for our new commercial support.
  • Add a mention of our ongoing user survey 2022, ask for participation.


  • Rebuild 64-Bit Octave mex files so that they should work on both Octave-6.3/6.4 and the new Octave-7.1 from HomeBrew.
  • Minor improvements to Screen() status messages.


  • Update some help texts wrt. hybrid graphics support. Some more configurations are verified to work with proper timing, e.g., AMD iGPU + NVidia dGPU Optimus style.
  • Update help PsychLinuxConfiguration.


Video of VSS2022 Psychtoolbox presentation.


Celia Foster was giving a 12 minute quick presentation about what’s new in Psychtoolbox since the last update at VSS 2019, as part of the Mathworks/INCF 1 hour session. Videos of much of that session may become available later, after editing/cutting etc.

For now, a video of Celia’s practice talk, only containing the 12 minute Psychtoolbox bit, without Q & A, is available on YouTube under this link:

Thanks to Mathworks, INCF and the volunteers in the room for hosting this session.


Celia & Mario

Psychtoolbox user survey 2022!


Dear Psychtoolbox users,

In recent years the Psychtoolbox Team has worked hard to improve Psychtoolbox itself and its services. We kindly ask you to fill out this survey, so that we can better understand the needs and wishes of our community. Your answers will greatly help us to shape the future of Psychtoolbox.

Click on this link to the survey form if you want to participate.

The survey is conducted by our host for all commercial services and matters, the “Medical Innovations Incubator GmbH, Tuebingen, Germany”.

As a thank you, you will receive a discount code for your next Psychtoolbox Support Membership purchase.

Many Thanks for your support and stay healthy!

Mario, Dee, Celia, Ingo and Anna

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