Modifying datafile

[au-justin]

My experiment utilizes the html_button_response plugin and I'm trying to change the contents of the datafile to show the actual button contents participants select, instead of 0 or 1.

Here is the code with the button choices array and test variable:

var test_stimuli = [
        {stimulus: images[0], choices: ['one', 'two']}, // 1
        {stimulus: images[1], choices: ['ten', 'twenty']}, // 2
];

var test = {
      type: jsPsychImageButtonResponse,
      stimulus: jsPsych.timelineVariable('stimulus'),
     choices: jsPsych.timelineVariable('choices'),
button_html: ['<button class="jspsych-btn" style = "position: relative; left: -50px; top: 100px; font-size: 40px;           height: 200px; width: 250px">%choice%</button>',
                    '<button class="jspsych-btn" style = "position: relative; left: 50px; top: 100px; font-size: 40px; height: 200px; width: 250px">%choice%</button>',
                    ],
data: {
       task: 'response'
     }

I would appreciate any help on this!

[jodeleeuw]

Hi @au-justin,

You can modify the data stored for a trial in the on_finish event. Something like this should work:

var test_stimuli = [
        {stimulus: images[0], choices: ['one', 'two']}, // 1
        {stimulus: images[1], choices: ['ten', 'twenty']}, // 2
];

var test = {
      type: jsPsychImageButtonResponse,
      stimulus: jsPsych.timelineVariable('stimulus'),
      choices: jsPsych.timelineVariable('choices'),
      button_html: [
            '<button class="jspsych-btn" style = "position: relative; left: -50px; top: 100px; font-size: 40px; height: 200px; width: 250px">%choice%</button>',
            '<button class="jspsych-btn" style = "position: relative; left: 50px; top: 100px; font-size: 40px; height: 200px; width: 250px">%choice%</button>',
       ],
      data: {
            task: 'response'
      },
      on_finish: (data) => {
            data.response = jsPsych.timelineVariable('choices')[data.response];
      }
}

This grabs the choices array and then uses the index stored in data.response to select the corresponding label from the array.