# Uncategorized **URL:** https://psychtoolbox.discourse.group/c/uncategorized/1.md [Latest](https://psychtoolbox.discourse.group/latest.md) · [Categories](https://psychtoolbox.discourse.group/categories.md) · [Tags](https://psychtoolbox.discourse.group/tags.md) --- ## [Welcome to the new Psychtoolbox Forum](https://psychtoolbox.discourse.group/t/welcome-to-the-new-psychtoolbox-forum/2869)
**Author:** [@Allen.Ingling](https://psychtoolbox.discourse.group/u/Allen.Ingling)\ **Replies:** 0\ **Last updated:** [January 9, 2020, 10:40pm UTC](https://psychtoolbox.discourse.group/t/welcome-to-the-new-psychtoolbox-forum/2869 "2020-01-09T22:40:34Z")
A New Website Welcome to the NEW Psychophysics Toolbox forum. This site replaces the old forum previously hosted at Yahoo Groups. If this is your first visit, get started by signing up using the blue "sign up" button in… --- ## [Playing a given sound from a given speaker](https://psychtoolbox.discourse.group/t/playing-a-given-sound-from-a-given-speaker/1323)
**Author:** [@lenarell](https://psychtoolbox.discourse.group/u/lenarell)\ **Replies:** 13\ **Last updated:** [August 14, 2025, 3:07pm UTC](https://psychtoolbox.discourse.group/t/playing-a-given-sound-from-a-given-speaker/1323 "2025-08-14T15:07:14Z")
Hello, I'm using Asio SoundCard with Motu driver and have 3 Speaker. I want to specify at a given time whether the sound will be played on Speaker 1 / 2 / 3 . How could I specify which Speaker should be used (n… --- ## [PTB + GUI in Matlab (R2018a) - Arithmetic Tasks](https://psychtoolbox.discourse.group/t/ptb-gui-in-matlab-r2018a-arithmetic-tasks/1078)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 6\ **Last updated:** [December 6, 2024, 11:27am UTC](https://psychtoolbox.discourse.group/t/ptb-gui-in-matlab-r2018a-arithmetic-tasks/1078 "2024-12-06T11:27:03Z")
Hi everyone, I would like to use Psychtoolbox for memory arithmetic tasks. I would like to show several numbers one by one on a screen ; after numbers presentation the subject need for example to make an addition o… --- ## [DrawFormattedText vertical center alignment behaves strange](https://psychtoolbox.discourse.group/t/drawformattedtext-vertical-center-alignment-behaves-strange/1865)
**Author:** [@bg7695](https://psychtoolbox.discourse.group/u/bg7695)\ **Replies:** 2\ **Last updated:** [November 1, 2024, 4:48pm UTC](https://psychtoolbox.discourse.group/t/drawformattedtext-vertical-center-alignment-behaves-strange/1865 "2024-11-01T16:48:42Z")
Hi there, I have a Lenovo b570e laptop, running Windows 7 SP1, CPU Intel Pentium B960, with 4Gb RAM and 120Gb SSD storage. I have a few days old, freshly installed, latest version Octave 5.1.0 "x86\_64-win64-m… --- ## [Communicating with NetStation](https://psychtoolbox.discourse.group/t/communicating-with-netstation/742)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 9\ **Last updated:** [June 21, 2024, 6:49am UTC](https://psychtoolbox.discourse.group/t/communicating-with-netstation/742 "2024-06-21T06:49:57Z")
Hi all, We've had a couple of problems with getting Matlab and EGI NetStation to communicate for quite some time now but were able to solve most of them. We are now trying to send event codes from Matlab 2016a to NetSt… --- ## [Sending Trigger via Parallel Port in Matlab](https://psychtoolbox.discourse.group/t/sending-trigger-via-parallel-port-in-matlab/79)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 2\ **Last updated:** [June 20, 2024, 10:17am UTC](https://psychtoolbox.discourse.group/t/sending-trigger-via-parallel-port-in-matlab/79 "2024-06-20T10:17:36Z")
Hi all, I have a similar problem as john.chen78 (https://groups.yahoo.com/neo/groups/psychtoolbox/conversations/topics/21844) but can’t reply to this chat for some reason. I would like to send a trigger via parall… --- ## [Busy cursor shows up even after HideCursor on MS-Windows](https://psychtoolbox.discourse.group/t/busy-cursor-shows-up-even-after-hidecursor-on-ms-windows/27)
**Author:** [@xrli2002](https://psychtoolbox.discourse.group/u/xrli2002)\ **Replies:** 2\ **Last updated:** [March 11, 2024, 1:57pm UTC](https://psychtoolbox.discourse.group/t/busy-cursor-shows-up-even-after-hidecursor-on-ms-windows/27 "2024-03-11T13:57:03Z")
I found this problem on two Windows 7 computers I tested: even after HideCursor, the busy cursor will show up if we WaitSecs for more than 5 seconds. The following function (with explanation in comment) demonstrates the … --- ## [open web browser in screen](https://psychtoolbox.discourse.group/t/open-web-browser-in-screen/464)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 3\ **Last updated:** [December 1, 2023, 8:01am UTC](https://psychtoolbox.discourse.group/t/open-web-browser-in-screen/464 "2023-12-01T08:01:42Z")
Hi there, I am working on stimuli for an experiment where participants do some things in matlab, then answer survey questions online, then go back to doing more things in matlab. Is it possible to open a web browser wi… --- ## [Present two distinct stimuli at different frquencies using flip?](https://psychtoolbox.discourse.group/t/present-two-distinct-stimuli-at-different-frquencies-using-flip/1651)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 2\ **Last updated:** [April 25, 2023, 4:36pm UTC](https://psychtoolbox.discourse.group/t/present-two-distinct-stimuli-at-different-frquencies-using-flip/1651 "2023-04-25T16:36:13Z")
Hi there, the problem i have is that i need to present two (or more boxes) flickering at distinct frequencies, say 10hz and 25hz. on screen at the same time. However as a call to flip sleeps matlab how is this possi… --- ## [Problem in collecting RT during RSVP detection task](https://psychtoolbox.discourse.group/t/problem-in-collecting-rt-during-rsvp-detection-task/412)
**Author:** [@jessica.galliussi](https://psychtoolbox.discourse.group/u/jessica.galliussi)\ **Replies:** 5\ **Last updated:** [February 17, 2023, 1:58am UTC](https://psychtoolbox.discourse.group/t/problem-in-collecting-rt-during-rsvp-detection-task/412 "2023-02-17T01:58:16Z")
Hi All, I'm writing a code for execute an RSVP detection task, but I have a problem in collecting RT and accuracy. Basically, what the code do at the moment is to present (in each trial) 16 squares: All squares are… --- ## [Closing Textures OSX](https://psychtoolbox.discourse.group/t/closing-textures-osx/695)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 3\ **Last updated:** [June 16, 2022, 2:12am UTC](https://psychtoolbox.discourse.group/t/closing-textures-osx/695 "2022-06-16T02:12:46Z")
Hello, Is there a way to quickly close all open textures without closing the screen? I noticed that there is not a CloseAllTextures screen command. I am trying to present multiple unique animations in a row and am… --- ## [Oculus CV1 connect but crash](https://psychtoolbox.discourse.group/t/oculus-cv1-connect-but-crash/30)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 2\ **Last updated:** [June 1, 2022, 4:52pm UTC](https://psychtoolbox.discourse.group/t/oculus-cv1-connect-but-crash/30 "2022-06-01T16:52:00Z")
Last week we were super happy to notice an update to Oculus support in April. We pulled out the Oculus CV1 headset and set up a new laptop to try it out. The Oculus is all set up and Psychtoolbox seems … --- ## [Gamepad('GetNumButtons', 1) returns zero](https://psychtoolbox.discourse.group/t/gamepad-39-getnumbuttons-39-1-returns-zero/298)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 11\ **Last updated:** [February 15, 2022, 3:10pm UTC](https://psychtoolbox.discourse.group/t/gamepad-39-getnumbuttons-39-1-returns-zero/298 "2022-02-15T15:10:59Z")
Hi, I have an Xbox 360 controller hooked up to a USB port on my MacBook Air running OS 10.8.4 with Matlab R2010a and the latest PTB extensions. I got Mac OS to recognize the controller by installing a driver that is a… --- ## [Random only for the first stimulus](https://psychtoolbox.discourse.group/t/random-only-for-the-first-stimulus/396)
**Author:** [@emiliecaspar](https://psychtoolbox.discourse.group/u/emiliecaspar)\ **Replies:** 6\ **Last updated:** [August 5, 2021, 8:16pm UTC](https://psychtoolbox.discourse.group/t/random-only-for-the-first-stimulus/396 "2021-08-05T20:16:19Z")
Hello everybody! I'm trying to program an "alea command", in the way to introduce a random choice of stimuli, but ONLY for the first stimulus. You can see the basic script in the files ('Script Libet'). But the p… --- ## [should KbName('Return') return two keycodes?](https://psychtoolbox.discourse.group/t/should-kbname-39-return-39-return-two-keycodes/1129)
**Author:** [@denispelli](https://psychtoolbox.discourse.group/u/denispelli)\ **Replies:** 10\ **Last updated:** [August 4, 2021, 7:13pm UTC](https://psychtoolbox.discourse.group/t/should-kbname-39-return-39-return-two-keycodes/1129 "2021-08-04T19:13:49Z")
Typing this returns two key codes: \>\> KbName('return') ans = 40 158 Is that right? I expected just one. The example code provided in the help for KbName seems to assume that only one value will be returned. … --- ## [PST Chronos® response box with Psychtoolbox?](https://psychtoolbox.discourse.group/t/pst-chronos-response-box-with-psychtoolbox/166)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 2\ **Last updated:** [May 6, 2021, 4:51pm UTC](https://psychtoolbox.discourse.group/t/pst-chronos-response-box-with-psychtoolbox/166 "2021-05-06T16:51:31Z")
Hi all, My aim is to receive key presses from a response box by PST (Chronos®) and sending it to MATLAB. I am aware of the function CMUBox.m in Psychtoolbox, which is supposed to receive responses from PST respon… --- ## [Scale Slider](https://psychtoolbox.discourse.group/t/scale-slider/146)
**Author:** [@wdedoncker93](https://psychtoolbox.discourse.group/u/wdedoncker93)\ **Replies:** 10\ **Last updated:** [April 27, 2021, 6:31am UTC](https://psychtoolbox.discourse.group/t/scale-slider/146 "2021-04-27T06:31:23Z")
Hi there, I am just wondering whether it is possible to create a Scale Slider in PTB, just like you can using the GUI interface in MatLab. I want to measure confidence on a scale of 1 to 10 using a scale slider … --- ## [Check a key released](https://psychtoolbox.discourse.group/t/check-a-key-released/1704)
**Author:** [@sebastien\_crouzet](https://psychtoolbox.discourse.group/u/sebastien_crouzet)\ **Replies:** 1\ **Last updated:** [February 9, 2021, 4:40pm UTC](https://psychtoolbox.discourse.group/t/check-a-key-released/1704 "2021-02-09T16:40:34Z")
Hi, I run actually an experiment with PTB 2.54 on windows. I want to display a stimulus and check for response of the subject (this is done without problems). The problem is that i want the subject to keep his 2 in… --- ## [GStreamer Install Problem](https://psychtoolbox.discourse.group/t/gstreamer-install-problem/268)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 3\ **Last updated:** [January 28, 2021, 5:59pm UTC](https://psychtoolbox.discourse.group/t/gstreamer-install-problem/268 "2021-01-28T17:59:23Z")
I'm getting the following: ---- PsychStartup: Environment variable GSTREAMER\_1\_0\_ROOT\_X86\_64 is undefined. PsychStartup: Either GStreamer-1.4 is not installed at all, or if it is installed then something PsychSta… --- ## [Using CreateProceduralSineGrating function to create colored gratings](https://psychtoolbox.discourse.group/t/using-createproceduralsinegrating-function-to-create-colored-gratings/520)
**Author:** [@thesnarkisaboojum](https://psychtoolbox.discourse.group/u/thesnarkisaboojum)\ **Replies:** 4\ **Last updated:** [October 22, 2020, 2:17am UTC](https://psychtoolbox.discourse.group/t/using-createproceduralsinegrating-function-to-create-colored-gratings/520 "2020-10-22T02:17:59Z")
Hello, I am using the CreateProceduralSineGrating to create color modulated gratings. My goal is to create a grating which peaks at green cyan (RBG \[0 0.8 0.5\]) and troughs at middle cyan \[0 0.5 0.5\]. However, I ha… --- ## [crash of PsychPortAudio](https://psychtoolbox.discourse.group/t/crash-of-psychportaudio/512)
**Author:** [@mbcai](https://psychtoolbox.discourse.group/u/mbcai)\ **Replies:** 2\ **Last updated:** [May 9, 2020, 1:30am UTC](https://psychtoolbox.discourse.group/t/crash-of-psychportaudio/512 "2020-05-09T01:30:27Z")
Dear colleagues, I am experiencing problem with PsychPortAudio now. When I typed devices = PsychPortAudio('GetDevices'); the Matlab crashes and give me the following error log. This happens even after I update my psych… --- ## [Compiling an app with mogl?](https://psychtoolbox.discourse.group/t/compiling-an-app-with-mogl/1965)
**Author:** [@mattjdunn](https://psychtoolbox.discourse.group/u/mattjdunn)\ **Replies:** 4\ **Last updated:** [May 8, 2020, 3:18am UTC](https://psychtoolbox.discourse.group/t/compiling-an-app-with-mogl/1965 "2020-05-08T03:18:20Z")
Hi, I'm trying to deploy a PTB routine in order to run it on a machine that doesn't have MATLAB installed. I'm using the 'Application Compiler' tool in MATLAB. Upon running the compiled binary, I receive an error fr… --- ## [Matlab Compiler](https://psychtoolbox.discourse.group/t/matlab-compiler/779)
**Author:** [@kohrrob](https://psychtoolbox.discourse.group/u/kohrrob)\ **Replies:** 1\ **Last updated:** [May 8, 2020, 3:14am UTC](https://psychtoolbox.discourse.group/t/matlab-compiler/779 "2020-05-08T03:14:17Z")
I was looking into making stand alone versions of matlab scripts that use the psychtoolbox. MathWorks offers "MATLAB Compiler 3.0.1" url: http://www.mathworks.com/products/compiler/description1.html which is sup… --- ## [Unable to detect the First touch using GetMouse or GetClicks ?](https://psychtoolbox.discourse.group/t/unable-to-detect-the-first-touch-using-getmouse-or-getclicks/1281)
**Author:** [@Allen\_Ingling](https://psychtoolbox.discourse.group/u/Allen_Ingling)\ **Replies:** 3\ **Last updated:** [March 3, 2020, 9:00am UTC](https://psychtoolbox.discourse.group/t/unable-to-detect-the-first-touch-using-getmouse-or-getclicks/1281 "2020-03-03T09:00:45Z")
Hi, I'm using Psychtoolbox. I usually wait for to detect a touch input on the ''Screen(theWindow)'', it works usually fine when I use my touchpad but I have to double tap when I use the touchscreen, Could somebody pro… --- ## [Multiple movies](https://psychtoolbox.discourse.group/t/multiple-movies/3013)
**Author:** [@jkawa](https://psychtoolbox.discourse.group/u/jkawa)\ **Replies:** 2\ **Last updated:** [February 7, 2020, 12:21am UTC](https://psychtoolbox.discourse.group/t/multiple-movies/3013 "2020-02-07T00:21:24Z")
Dear all, I would like to display multiple different movies (but same length) concurrently. I simply extended the SimpleMovieDemo.m by repeating the critical sentences like below and it worked. Is this the best way? (I … --- ## [SimpleMovieDemo crashes?](https://psychtoolbox.discourse.group/t/simplemoviedemo-crashes/3011)
**Author:** [@kira](https://psychtoolbox.discourse.group/u/kira)\ **Replies:** 9\ **Last updated:** [February 4, 2020, 11:34pm UTC](https://psychtoolbox.discourse.group/t/simplemoviedemo-crashes/3011 "2020-02-04T23:34:18Z")
Hello - I’m having issues even running SimpleMovieDemo - it loads a white screen then a black screen and then Matlab crashes (so I don’t even see the actual error). It’s on Windows. I have Gstreamer installed and did t… --- ## [Fixing Failed to map GPU low-level control Warning Message](https://psychtoolbox.discourse.group/t/fixing-failed-to-map-gpu-low-level-control-warning-message/38)
**Author:** [@anthony.sali](https://psychtoolbox.discourse.group/u/anthony.sali)\ **Replies:** 1\ **Last updated:** [January 28, 2020, 9:17pm UTC](https://psychtoolbox.discourse.group/t/fixing-failed-to-map-gpu-low-level-control-warning-message/38 "2020-01-28T21:17:25Z")
Hello, I'm setting psychtoolbox up on a machine running Ubuntu 18.04.1 with an AMD Radeon (TM) Pro WX 4100 and the open-source driver. I've run PsychLinuxConfiguration and rebooted the machine as instructed, but I am… --- ## [Random but not more than 3 times the same draw in a row](https://psychtoolbox.discourse.group/t/random-but-not-more-than-3-times-the-same-draw-in-a-row/3006)
**Author:** [@Pierre](https://psychtoolbox.discourse.group/u/Pierre)\ **Replies:** 1\ **Last updated:** [January 28, 2020, 3:11pm UTC](https://psychtoolbox.discourse.group/t/random-but-not-more-than-3-times-the-same-draw-in-a-row/3006 "2020-01-28T15:11:53Z")
Dear all, I need to display 2 stimuli side by side on a screen, but in random positions (left or right). To do this, I firstly created a simple 2 values vector (posx) within a Shuffle function, giving the center positi… --- ## [Connect dots with mouseclick](https://psychtoolbox.discourse.group/t/connect-dots-with-mouseclick/3005)
**Author:** [@Marusama](https://psychtoolbox.discourse.group/u/Marusama)\ **Replies:** 1\ **Last updated:** [January 28, 2020, 12:39pm UTC](https://psychtoolbox.discourse.group/t/connect-dots-with-mouseclick/3005 "2020-01-28T12:39:47Z")
Hi, I’m new to psychtoolbox! I have a code in which 5 dots with are randomly generated. I wanted to connect them with a line via mouse click. first, here is the code: clear; ListenChar(1); Screen(‘Preference’, ‘Skip… --- ## [Screen issue with Eyelink](https://psychtoolbox.discourse.group/t/screen-issue-with-eyelink/2989)
**Author:** [@12bc10](https://psychtoolbox.discourse.group/u/12bc10)\ **Replies:** 1\ **Last updated:** [January 25, 2020, 4:58am UTC](https://psychtoolbox.discourse.group/t/screen-issue-with-eyelink/2989 "2020-01-25T04:58:57Z")
I am a researcher in Canada who just updated some new computers in the lab running psychtoolbox with eyelink. Info: psychtoolbox 3.0.16 Windows 10 Error present for all eyelink demos & custom code Error code: EYELI… [Next page](https://psychtoolbox.discourse.group/c/uncategorized/1.md?page=1)