muting a plugin data saving protocol

[gorkemer]

Hello everyone,

In our experiment, there is one test trial and one feedback trial. I put them in a timeline like this:

var testProcedureGain = {
    timeline: [test_trial, feedback_trial],
    timeline_variables: test_images
};

This is all good. But when it comes to saving to MySQL database, I see rows of feedback trials which are mostly “null”. This is normal because feedback is actually a trial and jspsych’s plugin defaults run its data-saving procedure. Please see the image attached here.

Is there a common way to entirely stop a plugin trial from saving to the database? Something like a mute?

1- I tried to merge the feedback trial into the test-trial. I can edit the plugin by changing the after_response function and use display_element and then add var = html_content = “something”, but there I can only use response.key and I need not just keyboard response but more from test trial feature parameters, and I can’t seem to access them in there (those results in ‘undefined’).

This is how I do normally access trial parameters to be used used for feedback response.

on_finish: function (data) {
      	var pair_type = jsPsych.data.get().last(1).values()[0].pair_type; // test stimuli type
	var pair_ori = jsPsych.data.get().last(1).values()[0].pair_ori; // test stimuli orientation

..

2- Another way to do that would be doing it after on_finish:
Is there a way to add an extra function to use display_element?
on_finish: function (data, display_element)
Show something using display_element
I can’t seem to work this around either.

I also tried removing trial_data from the jsPsych.finishTrial(), but I don’t solve the problem.

Any help in finding a direction is much appreciated!

Gorkem

[becky-gilbert]

Hi Gorkem,

Could you just remove all of the feedback trials from the jsPsych data before you send the data back to the server? For instance using jsPsych's data manipulation functions like filter or filterCustom?

Otherwise your first option seems like it should work. You can edit the plugin so that it takes the correct response as a parameter (or any other information you need to score the response, like type and orientation).

plugin.info = {
  name: 'html-keyboard-response',
  description: '',
  parameters: {

    // other parameters here...

    stim_type: {
      type: jsPsych.plugins.parameterType.STRING,
      pretty_name: 'stim type',
      default: null,
      description: 'Stim type.'
    },
    stim_orientation: {
      type: jsPsych.plugins.parameterType.STRING,
      pretty_name: 'stim orientation',
      default: null,
      description: 'Stim orientation.'
    },
}

And then you can pass those values into the plugin when you set up the trial, so you'll be able to use that information in the after_response function to determine what the feedback text should be. You'll also want to change the plugin so that the end_trial function is only called after your feedback display is finished.

var after_response = function(info) {
  // after a valid response, the stimulus will have the CSS class 'responded'
  // which can be used to provide visual feedback that a response was recorded
  display_element.querySelector('#jspsych-html-keyboard-response-stimulus').className += ' responded';

  // only record the first response
  if (response.key == null) {
    response = info;
  }

  // response.key tells you what key was pressed
  // trial.stim_type and trial.stim_orientation give you the info that you need to score the response
  // set up a variable to hold the feedback text, and use the response and condition info
  // to store the appropriate feedback text in this variable
  var feedback;
  if (trial.stim_type == "x" & trial.stim_orientation == "y" & response.key == "a") {
    feedback = "Correct!";
  } else {
    feedback = "Incorrect";
  }
  // display feedback
  display_element.innerHTML = feedback;
  // call the end_trial function after some delay, e.g. 3 seconds
  jsPsych.pluginAPI.setTimeout(function() {
    end_trial();
  }, 3000);
}

I don't think your second option will work because by the time the on_finish function is called, the trial is over, and there's really no way to get jsPsych to stop there while you show feedback on the screen (but I could be wrong!).

[gorkemer]

@becky-gilbert Thank you very much, Becky. The data manipulation function of filter() solved my problem very quickly, I should have known that but I thank you for the other solution as well. It would also work.

Best,
Gorkem