add properties to all events of a trial

[AlexStuffs]

Hi all,

I've got another very basic question.
In my task, trials are constituted by a number and a mask.
There is a practice phase and a test phase.
Numbers are built in distinct timelines but the mask var is common to both phases.
Here an extract of the code:

var mask = {
    type: 'image-keyboard-response',
    stimulus: 'img/mask.png',
    choices: ['space'],
    trial_duration: 1000
    response_ends_trial: false,
  }

  var number = {
    type: 'html-keyboard-response',
    stimulus: function() {
  // this is how you can combine different variables from your timeline_variables array
  return '<p style="font-size: '+jsPsych.timelineVariable('fontsize', true)+'px;">'+jsPsych.timelineVariable('number', true)+'</p>';
  },
    choices: ['space'],
    trial_duration: 1000,
    data: {
      condition: jsPsych.timelineVariable('condition')
    },
    on_finish: function(data){
      if(data.condition == 'Go'){
        data.correct = jsPsych.pluginAPI.compareKeys(data.key_press, 'space');
      } else {
        data.correct = jsPsych.pluginAPI.compareKeys(data.key_press, '');
      }
    }

    var fontSize = ['<div style="font-size:48px;">','<div style="font-size:72px;">','<div style="font-size:94px;">','<div style="font-size:100px;">','<div style="font-size:120px;">']
    var fontSizeSample = jsPsych.randomization.sampleWithReplacement(fontSize, 12);
    var practice = {
      timeline: [number, mask],
      timeline_variables: [
        {number: ""+fontSizeSample[0]+"1</div>", condition: 'Go'},
        {number: ""+fontSizeSample[1]+"5</div>", condition: 'Go'},
        {number: ""+fontSizeSample[2]+"8</div>", condition: 'Go'},
        {number: ""+fontSizeSample[3]+"4</div>", condition: 'Go'},
        {number: ""+fontSizeSample[4]+"3</div>", condition: 'NoGo'},
        {number: ""+fontSizeSample[5]+"7</div>", condition: 'Go'},
        {number: ""+fontSizeSample[6]+"5</div>", condition: 'Go'},
        {number: ""+fontSizeSample[7]+"3</div>", condition: 'NoGo'},
        {number: ""+fontSizeSample[8]+"9</div>", condition: 'Go'},
        {number: ""+fontSizeSample[9]+"2</div>", condition: 'Go'},
        {number: ""+fontSizeSample[10]+"1</div>", condition: 'Go'},
        {number: ""+fontSizeSample[11]+"8</div>", condition: 'Go'}
      ],
      data: {
        'test_part': 'practice'
      },
  }

  var test = {
    timeline: [number, mask],
    timeline_variables: test_stimuli,
    data: {
      'test_part': 'test'
    }
  }

Here, the 'test_part' values are defined in the var test and the var practice is applied to the'test_phase'variable of the number data. However, I would like to apply this to both the number and the mask events of the trial.
I tried jsPsych.data.addProperties and on_trial_finish but it didn't work.

I guess that's a very basic question with a very simple answer :)

Alex

[jodeleeuw]

Hi Alex,

The way that you have the practice and test variables defined with data: {'test_part': 'practice'} and data: {'test_part': 'test'} should work. What behavior are you seeing? Are you modifying this data anywhere else in the script?

[AlexStuffs]

In the data, the mask object doesn't not have the property:

"success","trial_type","trial_index","time_elapsed","internal_node_id","rt","stimulus","key_press","test_part","condition","correct","trial_rt","trial_correct"
"true","fullscreen","0","2940","0.0-0.0","","","","","","","",""
"","html-keyboard-response","4","4993","0.0-4.0-0.0","null","<p style=""font-size: undefinedpx;""><div style=""font-size:94px;"">1</div></p>","null","practice","Go","false","",""
"","image-keyboard-response","5","5899","0.0-4.0-1.0","0","img/mask.png","null","","Go","","0","false"
"","html-keyboard-response","6","6152","0.0-4.0-0.1","null","<p style=""font-size: undefinedpx;""><div style=""font-size:120px;"">5</div></p>","null","practice","Go","false","",""
"","image-keyboard-response","7","7056","0.0-4.0-1.1","0","img/mask.png","null","","Go","","0","false"
"","html-keyboard-response","8","7309","0.0-4.0-0.2","null","<p style=""font-size: undefinedpx;""><div style=""font-size:94px;"">8</div></p>","null","practice","Go","false","",""
"","image-keyboard-response","9","8214","0.0-4.0-1.2","0","img/mask.png","null","","Go","","0","false"

That's probably because I add several properties to the mask - I know, that's a very ugly coding, I didn't smooth it for now ;) - :

    var mask = {
      type: 'image-keyboard-response',
      stimulus: 'img/mask.png',
      choices: function(){
        var last_number_key_pressed = jsPsych.data.getLastTrialData().values()[0].key_press;
        if (last_number_key_pressed == 32){return ['none'];} else {return ['space'];}
      },
      trial_duration: function(){
        var last_number_rt = jsPsych.data.getLastTrialData().values()[0].rt;
        if(last_number_rt > 0){return 1150-last_number_rt;} else {return 900;}
      },
      response_ends_trial: false,
      data: function(){
        var last_trial_condition = jsPsych.data.get().last(1).select('condition').values;
        return{condition: last_trial_condition};
        // var last_test_part = jsPsych.data.get().last(1).select('test_part');
        // data.test_part = last_test_part;
      },
      on_finish: function(data){
        var max_rt = jsPsych.data.get().last(2).select('rt').max();
        var max_key_press = jsPsych.data.get().last(2).select('key_press').max();
        var current_rt = data.rt;
        if (current_rt >0){
          data.rt = current_rt+250;data.trial_rt=max_rt+250;}else{
          data.rt = 0;data.trial_rt=max_rt;}
        if(data.condition == 'Go'){
          data.trial_correct = jsPsych.pluginAPI.compareKeys(max_key_press, 'space');
        } else {
          data.trial_correct = jsPsych.pluginAPI.compareKeys(max_key_press, '');
        }
      }
    }

The idea is to have an readable row about the trial (a number + a mask) for future analyses as the participant will have the possibility to respond during the number or the mask if he didn't during the number.
I had some ideas to make that:

1. create a blank event in the trial (no display) that should have the trial number, the rt, correct, test_part, number and condition value of the number and/or the mask
2. bring back to the mask event theses values (that's the goal of the ugly lines in the on_finish part)
   As you can see, I'm trying the 2) -not sure that's the best way- and it seems to work (trial_correct and trial_rt) except for the test_part.

[jodeleeuw]

Hmm, this all still looks like it should work. I wonder if there is some unintended behavior when the timeline has a data object and the trial object defines the data object as a function.

Can you try changing the data object to this and see if it helps?

data: {
	condition: function(){
        	return last_trial_condition = jsPsych.data.get().last(1).select('condition').values;
      	}
}

[AlexStuffs]

I replaced this:

      data: function(){
        var last_trial_condition = jsPsych.data.get().last(1).select('condition').values;
        return{condition: last_trial_condition};

in the mask part of the code by your code and it perfectly works now!
(I really don't get the difference, need some javascript lessons I guess!)

Thanks!

[jodeleeuw]

The other way doesn't work because of an edge case that I hadn't considered. If the data parameter for a trial is a function, then jspsych.js has trouble merging the data from the timeline down into the trials. But if the data parameter is an object with functions as values then the merging works. We'll patch this in the future so your original way will work too. Tracking this in #1231.