Psychtoolbox KbQueueXXX functions in Ubuntu

1 次查看（过去 30 天）
Yu Takahashi
Yu Takahashi 2021-4-19
Dear members
I am having a very difficult time using KbQueueXXX functions (i.e., KbQueueCreate, KbQueueStart, KbQueueCheck, KbQueueRelease) to record key presses, kept bumping into errors while following some pretty old step-by-step instructions (e.g., Source One and Two listed at the very end of this post).
I tried to read through the psychtoolbox documentations but still confused with the information presented.
Some very basic questions such as
e.g., should I call
PsychHID('KbQueueStart', device)
or
KbQueueStart(device)
to look for keypresses?
I was also wondering whether there is any working demo scripts or more recent sources/ tutorials that I can learn from.
Thanks in advance!
My script:
%%create the Queue device and specify the allowed keys
device =7;
keys=[45 46];
keylist=zeros(1,256);
keylist(keys)=1;
KbQueueCreate(device,keylist);
...
KbQueueStart(device); % look for key presses within a specified time limit
while TimeOut == 0
[pressed, firstpress] = KbQueueCheck(device); %check response
if pressed
if firstPress(45)>0
...
TimeOut = 1;
break
elseif firstPress(46)>0
...
TimeOut = 1;
break
end
elseif TimeInLoop > 10
...
TimeOut = 1;
break
end
end
KbQueueRelease(device);
Error msg presented :
Error using PsychHID
Usage:
[keyIsDown, firstKeyPressTimes, firstKeyReleaseTimes, lastKeyPressTimes, lastKeyReleaseTimes]=PsychHID('KbQueueCheck' [, deviceIndex])
Error in KbQueueCheck (line 61)
[pressed, firstPress, firstRelease, lastPress, lastRelease] = PsychHID('KbQueueCheck', deviceIndex);
Error in myscript (line 465)
[pressed, firstpress] = KbQueueCheck(device); %check response
References
Source One
http://cbs.fas.harvard.edu/science/core-facilities/neuroimaging/information-investigators/matlabfaq
Source Two
ftp://ftp.tuebingen.mpg.de/pub/pub_dahl/stmdev10_D/Matlab6/Toolboxes/Psychtoolbox/PsychDocumentation/KbQueue.html
the principle seemed to be
  1. KbQueueCreate: create a list of keys
  2. KbQueueStart: start “waiting” for keypresses
  3. put KbQueueCheck: put this in a while loop to look for specific key presses
  4. KbQueueRelease : end the “wait”
Software environment
ubuntu 20.04.1 LTS
matlab 2019b
psychtoolbox 3.0.17

请先登录，再回答此问题。

回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Installation and Operational Settings 的更多信息

标签

产品


版本

R2019b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by