Handle internally generated events like user input

[henrySol]

Hi everyone, hope you are doing well!

I am currently trying to figure out a way to use events that are generated by my experiment script instead of user input. What I am looking for is something like this:

• An event is dispatched based on some condition, for example using a simple function like this:
  function simulateKeyPress(keyCode) { var event = new KeyboardEvent('keydown', { keyCode: keyCode }); document.dispatchEvent(event); };

• A jspsych trial, for example a jsPsychHtmlKeyboardResponse trial, handles the event as if it was an actual key press by the user. The event should be handled like a user response.

I have already figured out how to set up event listeners that handle the dispatched events. But I cannot find a way to let the jspsych trial object handle the event as a user response/user input (instead of listening for actual key presses by the user). Perhaps I have to modify the relevant plugins? Any help would be greatly apreciated!

Thanks in advance and enjoy your days

Henry

[jodeleeuw]

Hi @henrySol

You probably need to dispatch the event on the specific element that contains the jsPsych experiment. When plugins use getKeyboardResponse the event listener is attached to the same element that is accessed via jsPsych.getDisplayContainerElement().

Something like the following should work:

jsPsych.getDisplayContainerElement().dispatchEvent(event);

[henrySol]

Hey @jodeleeuw ,

this was exactly what I needed! Thanks a lot! This was the missing piece and now I will be able to handle signals that come in via a serial port as user input (key presses), which allows me to use jsPsych in an MRI scanner environment (which is great).