As with all major releases you should check carefully that your experiment still runs as expected. In particular for this release check the timings of your Builder experiment (they should be better than they were before but do check).
Faster audio with PTB backend
This is the first version to provide the Psychtoolbox audio backend. To test that out you need to change your settings. e.g.: ['PTB', 'pyo', 'sounddevice'] but this engine is considerably faster than all the other options, supporting sub-ms precision on most hardware, so if you care at all about audio latencies then you should give it a try. In future versions this will become the default audio option.
Better stimulus timing in Builder scripts
The other big change (and beware this will probably alter the timing of your existing studies) is that experiements setting the start/stop of components using Time (s) settings will have different timing. PsychoPy has a new function Window.getFutureFlip() allowing us to find out the time of the next screen refresh, which allows more accurate timing tests for your visual stimulus components. Rather than basing a decision (should we draw that stimulus?) on the current time the decision is now based on what the time will be when the flip occurs. This should mean that the previous advice to use Frames for timing of short stimuli will no longer be needed.
Many fixes
There were also a lot of bug fixes in this release and hopefully it will be a smoother experience for all!
And hereâs a pretty picture of the new audio lib in a few repetitions of a sound under Win10 with standard built-in audio hardware. The yellow trace(s) represent a simple tone, the cyan trace is a labjack trigger. Note that the gridlines represent 1ms.
To get this precision you do need to pre-schedule the sound using snd.play(when)
Existing experiments will use the Window.getFutureFlip() function when re compiled? Or just run? Or this will apply only to new built experiments. I am asking for experiments made on Builder, of course.
Existing scripts wonât change. You need to generate the script from Builder for this to occur, but that typically occurs on every run (or are you running your study from coder instead?)
On another note, I seem to be having some issues with the new version: it doesnât run any of my experiments that were created with the previous version. As a matter of fact, it doesnât even open the Demos. I keep getting an error. Any idea why this is happening?
I had a similar experience with psychopy 3.2 on Ubuntu 18.04, and I found it cannot deal with directories containing a space in their names. For example when I chose âunpack demosâ in the builder app, psychopy created a directory named âpsychopy3 demosâ or similar and could not open the demo scripts afterwards because of the space in the name. You seem to have placed something in âc:\program filesâ, but because of the space psychopy only sees âc:\programâ.
A related problem occured for me with scripts that had brackets in their names, which ran in the previous version of psychopy and were ânot foundâ by the current version.
So it seems a workaround is not to use certain characters in file and directory names.
Strangely, I canât replicate the effect on my machine (must have different settings in my terminal) but I know what that will be and Iâm sure we can have a fix very quickly
thanks for this new updated version of PsychoPy! I have some questions regarding the following item:
Can you clarify whether this is also true for PsychoJS? I have been collecting data with PsychoJS (PsychoPy ver. 3.1.1) for the whole summer and I have noticed that stimulus timing for short routines (~34 ms) is very unstable (see this topic). This has forced us to collect data from more subjects than usual so to ensure a reasonable amount to data to analyze after trimming trials with the exceeding prime durations. It would be great if you guys had figured out how to make durations of short routines more stable in PsychoJS because it would allow us to save time and money.
The timing structure hasnât yet changed for the PsychoJS lib. We will look into whether this can be done but it isnât the first priorit right now. The timing improvments are about making better decisions, given a specification in seconds, about whether we can fit in one more frame.
For brief presentations like that on any platform we would really recommend that you specify stimulus duration in nFrames and that IS available on PsychoJS, and it sounds from your other post as if youâre doing that.
Iâll respond in the other thread with some explanations about the data youâve recorded on timing and about a) why timing is worse under a browser b) what parts of the fluctuation youâre seeing are ârealâ in terms of stimulus duration
I just updated my version of psychopy to the newest one (I think) using
pip install psychopy
It gave me an error about not having the correct version of python despite having version 3.6 installed. So I went into /usr/bin and edited the psychopy file to point it directly at python3.6. Now when I try to launch the app, I get the message
File â/usr/bin/psychopyâ, line 10, in
from psychopy.app._psychopyApp import PsychoPyApp, version
ModuleNotFoundError: No module named âpsychopyâ
What have I done wrong? Im on Lubuntu 18.04 32bit.
Most likely pip has installed PsychoPy to a different Python installation. Rather than doing simple pip install....
you could do python -m pip install psychopy
so that you can decide more clearly which pip/python is used in the installation
