Starting with version 3.2.0, the psychophysics plugin can present visual stimuli using PixiJS functionality. You can turn on and off Pixi mode, but if you present drifting gabor patches Pixi mode should be turned on.

If you are interested in Pixi mode, please see the results of an accuracy test conducted in April 2022 at first. I obtained good results in total, but I am a little concerned about Firefox. Note that I have only checked one laptop.

How to turn on Pixi mode

Upload files to a web server

To use PixiJS, in priciple, the program files must be uploaded to a web server. However, some programs will work on a local PC (e.g., a prgoram presenting rectangles and circles.)

Include PixiJS using a script tag

<script src=""></script>

Set the pixi property as true

The pixi property is false by default, i.e., Pixi mode is off.

const trial = {
    type: jsPsychPsychophysics,
    pixi: true,
    stimuli: [gabor],

How to check if the program is working in Pixi mode

Please open the JavaScript console window in your browser. If you are using Chrome on Windows, press Ctrl + Shift + I to open the console. You’ll see the following line in the console if the program runs in Pixi mode.


Known problems in Pixi mode

  • There may be a way to enable anti-aliasing, but I have yet to find it. You can clearly see the difference between anti-aliasing on and off.
  • You may feel a flash of screen immediately after the trial when the background color is not white. In this case, you can avoid the problem by writing as <body bgcolor="gray"></body>.
  • The quality of text seems to be better in non Pixi mode. For example, Pixi mode and Non Pixi mode

So, please switch between Pixi modes depending on the purpose of the experiment.

Advanced usage

Using the PixiJS application’s ticker, you can change attributes of the stimulus. See the “Writing an Update Loop” section in the PixiJS guides. To do the same thing in the psychophysics plugin, use the change_attr function. See demos/change_attributes.html and demos/elapsed_time_frame_pixi.html.

If you are familiar with PixiJS, you can make the PixiJS instances and include them in the stimuli property of the psychophysics plugin. See the demos/draw_part_of_image_pixi.html.