Psychtoolbox interfaces between Matlab or Octave and the computer hardware. The PTB core routines provide high performance 2D and 3D graphics with the highest color and luminance precision, timing precision and control. This both on standard displays, as well as with special visual stimulators, and with High Dynamic Range displays, and with a wide variety of Virtual/Augmented Reality devices. They expose raw OpenGL commands, support video playback and capture, as well as low-latency precisely timed audio playback and capture. They facilitate the collection of observer responses with high timing precision via various input modalities like keyboard, mouse, game controllers, multi-touch touch screens, response boxes, gaze trackers, and digital / analog i/o equipment. Ancillary helper routines support common needs like color space transformations, calibration, and psychometric procedures like, e.g., the QUEST threshold seeking algorithm and others.

Various 3rd party frameworks and higher level toolboxes are built on top of Psychtoolbox to make implementation of research data collection especially easy in specific sub-domains of neuroscience. For beginners or certain domains there also exist user friendly 3rd party graphical user interfaces, e.g., PsyBuilder.

You can also run some of your Psychtoolbox studies online, via VPixx Labmaestro service under https://vpixx.com/products/labmaestro-packngo.

Psychtoolbox has many active users, an active forum, and is widely cited. The current version supports at least Matlab R2024b on Linux, Windows and macOS, and Octave 6 and later on Linux, and Octave 7.3 on Windows, and Octave 9 on macOS.

Psychtoolbox News

Psychtoolbox updated

kleinerm

Psychtoolbox 3.0.22.0 “Oh wie schoen ist Panama!” was released at 28th May 2025.

You can download it as a zip file from the following link:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/releases/download/3.0.22.0/3.0.22.0.zip

This release is strongly recommended to upgrade to if you are a user of Psychtoolbox 3.0.20 on macOS or Windows, as it allows most reliable and smooth use under the new paid software license subscription model.

The complete development history can be found in our GitHub repository. The release tag is “3.0.22.0”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.22.0

This Psychtoolbox release was sponsored by Mathworks under the year 2024/2025 contract for significant enhancements, sponsoring the OpenXR hand tracking support as major new feature.

Compatibility changes wrt. Psychtoolbox 3.0.21.0:

  • This release no longer supports the Ubuntu 20.04-LTS “Focal Fossa” family of Linux operating system distributions, and siblings like Debian GNU/Linux 11 “Bullseye”. In fact, it requires Ubuntu 22.04.5-LTS “Jammy Jellyfish” with all updates installed, or Debian GNU/Linux 12 “Bookworm” and equivalent distributions, ie. Linux distributions where all software components are at least as modern and recent as those in Ubuntu 22.04.5-LTS. Psychtoolbox Mex files will no longer work on older distributions, or if some would appear to work, they might show various subtle and not so subtle malfunctions - iow. they woud be unfit for research grade data collection.

  • Psychtoolbox for Matlab on Linux now also requires a paid software subscription license, while the Octave variant for Linux remains free of cost to use.

Highlights:

  • New fast, mostly seamless fixed refresh rate switching on Linux with AMD graphics.

  • Hand tracking performance optimizations.

All:

  • Software subscription licenses can now also be activated during setup with user email+password of the account of the license manager self service portal. Psychtoolbox will fetch the correponding license key automatically.

  • License management now contains functionality needed for implementation of campus licenses, unattended auto setup of licenses, and educational licenses.

  • Performance optimizations for the articulated hand and finger tracking for OpenXR, which was introduced in Psychtoolbox 3.0.20.4. Now operates 20-30 times faster, doing its job in less than 0.5 msecs on average hardware.

  • PR655parsespdstr(): Fix to handle zero values in measurements correctly. Contributed by Danny Garside @da5nsy thanks!

  • Various other smaller refinements, bug fixes and documentation updates.

Linux:

  • Psychtoolbox was built and tested against Matlab R2024b and Octave 6.4 under Ubuntu 22.04.5-LTS. Now only works on Ubuntu 22.04-LTS and later.

  • Added workarounds for bugs in AMD’s Vulkan driver AMDVLK that have been introduced due to mistakes by AMD’s developers since version v-2023.Q2.2 and later, starting in May 2023. These bugs prevent 16 bpc ultra-high precision framebuffers to be reported as supported in both SDR and HDR mode of operation, with some driver versions even 10 bpc support is lacking in SDR Standard Dynamic Range mode! The bug prevents all AMD RDNA 3+ graphics cards with Navi 30 or later gpu family from using these 16 bpc framebuffers, and thereby from achieving up to 12 bpc effective output precision. Our new workaround tricks the faulty drivers into supporting these modes anyway and thereby restores the 10 bpc modes in SDR/HDR and tries to restore 16 bpc modes for up to 12 bpc effective output color precision in SDR and HDR again. While this has been confirmed to work on gpu’s of the AMD Vega gpu family and earier models, the situation on AMD Navi / RDNA gpu’s ist still unclear at time of this release. There might be additional bugs in the AMDVLK drivers still preventing this. Unfortunately the tester for this feature on AMD RDNA gpu’s has not reported back in reasonable time and we have to release now, with this question still to be answered.

  • Support for rapid, seamless video refresh rate switching on modern FreeSync capable AMD graphics cards, when used with a Variable Refresh Rate capable display device, connected via DisplayPort, e.g. suitable FreeSync, GSync and “Vesa DisplayPort Adaptive Sync” capable monitors. This can be triggered for a whole X-Screen with one or multiple active outputs via the command Screen('Framerate', screenId, 2, reqHz); or on a individual per-output basis via Screen('ConfigureDisplay', 'FineGrainedSwitchRefreshRate', screenId, outputId, reqHz); This allows to request an instant switch of the displays to a new video refresh rate reqHz within the variable refresh rate range supported by the display monitor, e.g., to run dynamic animations or movie playback at a specific exact rate, and switch that rate on a trial-by-trial basis if needed, with switching times in the range of only one to a few video refresh cycle duration. All AMD graphics cards since the Sea Island gpu family from around the year 2014 should be supported.

    The new test and demo VRRFixedRateSwitchingTest.m demonstrates and tests this.

  • Fix touchscreen enumeration for touchscreens operated by the “Intel Precision Touch and Stylus Daemon” iptsd version 3 and later. GetTouchDeviceIndices() now filters out the wrong touchscreen device and enumerates the correct devices.

Windows:

  • Psychtoolbox was built and tested against Matlab R2024b and Octave 7.3.

macOS:

  • Psychtoolbox was built and tested against native Matlab R2024b and against native Octave 9.4 from HomeBrew, on macOS 13.7.5 Ventura for Intel Macs, and on macOS 14.5 Sonoma for Apple Silicon Macs.

  • Add a Datapixx mex file for Matlab on Apple Silicon Macs, based on VPixx latest release. This is supposed, but not tested by us, to make basic support for VPixx devices work on macOS for Apple Silicon. Note that the Datapixx mex file for Octave is not ready and most likely broken on Apple Silicon, as of now.

Enjoy!

End of first batch of free trials for Psychtoolbox imminent

kleinerm

This is a reminder that the first large batch of free time limited trials for free use of Psychtoolbox 3.0.20 and later for Apple macOS and Microsoft Windows will end very soon for all those machines on which version 3.0.20 was first used before start of April 2025.

Free trials for those machines will end on coming Monday the 14th of April 2025, and further use of the software will require a paid software subscription license key, which you can buy from our store, accessible from www.psychtoolbox.net.

Free trials started for initial installations since April will always end 14 days after initial use of Psychtoolbox version 3.0.20 or later on a given machine.

We strongly recommend upgrading any 3.0.20 Psychtoolbox to at least version 3.0.21.0, but in general to the very latest published version.

Buy now and receive a license at a low early-bird rate!

For questions and discussions, follow this link to the discussion thread on our user forum.

For answers to frequently asked questions, follow this link to the slowly building FAQ on our Wiki.

Psychtoolbox updated

kleinerm

Psychtoolbox 3.0.21.0 “Fruity Aspirational Cashcow” was released at 31st March 2025.

You can download it as a zip file from the following link:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/releases/download/3.0.21.0/3.0.21.0.zip

This marks the end of life and any and all support for Psychtoolbox 3.0.20, what a short but eventful life it had! This release is strongly recommended to upgrade to if you are a user of Psychtoolbox 3.0.20 on macOS or Windows, as it allows most reliable and smooth use under the new paid software license subscription model that launches today, the 31st of March 2025.

The complete development history can be found in our GitHub repository. The release tag is “3.0.21.0”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.21.0

This Psychtoolbox release was sponsored by Mathworks under the year 2024/2025 contract for significant enhancements, sponsoring the OpenXR hand tracking support as major new feature.

Compatibility changes wrt. Psychtoolbox 3.0.20.4:

  • None.

Highlights:

  • Only improvements for license management for a hopefully smooth imminent start of the new software subscription licensing model on Apple macOS and MS-Windows.

  • We strongly recommend upgrading from Psychtoolbox 3.0.20 to 3.0.21 at your earliest convenience if you are a macOS or MS-Windows user, which will require a paid subscription license for versions 3.0.20 and later very soon! Previous users of Psychtoolbox 3.0.20 will have until 14th April 2025 to buy a license, as their free trial will run out during that day. New users will have a 14 day free trial on a given machine until they have to buy and activate a license.

  • This release is probably one of the very last ones, possibly the last one, to support almost end-of-life Ubuntu 20.04-LTS or other Linux distributions older than Ubuntu 22.04.5-LTS and equivalent, e.g., Debian GNU/Linux 12.0 (Bookworm).

All:

  • Improvements to license management via PsychLicenseManagement(); for imminent launch of the new software licensing business model on MS-Windows and macOS:

    • Allow a configurable maximum offline time (grace period) of more than 30 days.
    • Improved status messages.
    • Built in “News” push message support.
    • Support for offline “air-gapped” activation of licenses for select customers.

  • Various other smaller refinements, bug fixes and documentation updates.

Linux:

  • Psychtoolbox was built and tested against Matlab R2024a and Octave 5.2 and later.

Windows:

  • Psychtoolbox was built and tested against Matlab R2024a and Octave 7.3.

macOS:

  • Psychtoolbox was built and tested against native Matlab R2024a and against native Octave 9.4 from HomeBrew, on macOS 13.7.4 Ventura for Intel Macs, and on macOS 14.5 Sonoma for Apple Silicon Macs.

Enjoy!

News Archive