I want to run the code examples from Psychtoolbox but I got an error message.

Hi everybody,

I am new on Mathlab and trying to learn how to code. I wanted to run the code examples on my macbook air 2021 but it seems that there is a problem regarding my graphic card.

I got this message :

"PTB-WARNING: This is a Apple silicon based ARM M1 SoC or later with Apple proprietary gpu.

PTB-WARNING: All of Psychtoolbox own timing and timestamping mechanisms will not work on

PTB-WARNING: such a machine, leading to disastrously bad visual stimulus presentation timing

PTB-WARNING: and timestamping. Do not trust or use this machine if timing is of any concern!

PTB-WARNING: You may want to try enabling Psychtoolbox Vulkan display backend, after proper

PTB-WARNING: configuration. See 'help PsychImaging' the section about the 'UseVulkanDisplay'

PTB-WARNING: task, and 'help PsychHDR' for some more setup instructions for MoltenVK on macOS.

PTB-WARNING: Note that this approach is completely unsupported by us in case of any problems, and

PTB-WARNING: may just be as bad performance and timing-wise. It is completely untested on M1.

PTB-WARNING: A simple test case would be running SimpleHDRDemo. If it wouldn't flood the command

PTB-WARNING: window with error and warning messages, that would be mildly encouraging. Let us know.

PTB-INFO: Retina display. Enabling panel fitter for scaled Retina compatibility mode.

PTB-INFO: This is Psychtoolbox-3 for Apple macOS, under Matlab 64-Bit (Version 3.0.19 - Build date: Dec 16 2023).

PTB-INFO: OS support status: macOS version 13 ARM M1+ SoC is not yet tested or supported at all for this Psychtoolbox release..

PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.

PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with

PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.

PTB-INFO: For information about paid support, support memberships and other commercial services, please type

PTB-INFO: 'PsychPaidSupportAndServices'.

PTB-INFO: Using Cocoa + No display capture / compositor lockout for fullscreen window. Timing will be disastrous.

PTB-INFO: Installation of the PsychtoolboxKernelDriver is strongly recommended if you care about precise visual

PTB-INFO: onset timestamping or timing. See 'help PsychtoolboxKernelDriver' for installation instructions.

PTB-INFO: OpenGL-Renderer is Apple :: Apple M1 :: 2.1 Metal - 83.1

PTB-INFO: Renderer has 5461 MB of VRAM and a maximum 5461 MB of texture memory.

PTB-INFO: VBL startline = 1800 , VBL Endline = -1

PTB-INFO: Beamposition queries unsupported or defective on this system. Using basic timestamping as fallback.

PTB-INFO: Timestamps returned by Screen('Flip') will be therefore less robust and accurate.

PTB-INFO: Measured monitor refresh interval from VBLsync = 16.018059 ms [62.429535 Hz]. (290 valid samples taken, stddev=1.171966 ms.)

PTB-INFO: Reported monitor refresh interval from operating system = 16.666667 ms [60.000000 Hz].

PTB-INFO: Small deviations between reported values are normal and no reason to worry.

WARNING: Couldn't compute a reliable estimate of monitor refresh interval! Trouble with VBL syncing?!?

----- ! PTB - ERROR: SYNCHRONIZATION FAILURE ! -----

One or more internal checks (see Warnings above) indicate that synchronization

of Psychtoolbox to the vertical retrace (VBL) is not working on your setup.

This will seriously impair proper stimulus presentation and stimulus presentation timing!

Please read 'help SyncTrouble' for information about how to solve or work-around the problem.

You can force Psychtoolbox to continue, despite the severe problems, by adding the command

Screen('Preference', 'SkipSyncTests', 1); at the top of your script, if you really know what you are doing.

Error using AlphaRotateDemo

Error using Screen

See error message printed above."

Can you tell me how to change it?

Answer 1

[Image Analyst]

It looks like it's explicitly giving you a string warning that you should not use their toolbox on your computer, but gives you directions to continue using it at your own risk. I would either run it on a different computer, or if you don't care about timings, do what it says about adding that command at the top of your script.

[John D'Errico]

It does seem they gave very complete warnings about the problem, and what to do to deal with it, though it is possible the indicated fix might not be what makes @Roxane happy. Such is life.

[Roxane]

okay thank you for your answer !

Which kind of computer should I use then?

Best regards

[Image Analyst]

Try a non-M Mac or a Windows computer. Or ask the publishers of that software.