rdk trial crashes after no response/max trial duration of html keyboard response

[anika-t-l]

Hi there,

I've been stuck on this issue for the past few hours:
I have an rdk task with several blocks. Between the individual task blocks, I inserted breaks and previously let participants determine themselves when to resume, so I had set trial_duration to null and choices to jsPsych.ALL_KEYS. Now however, I want to restrict the maximum amount of time participants have for their break, but I still want the break to end when they make a response before the trial_duration is reached.
I set trial_duration and that works, but if no response is made and the trial ends, upon the first response to the next trial of the rdk, I get the error "Cannot read property of type "tolowerCase" " and the experiment crashes.
[Code snippet below]
Could somebody give me a hint what the issue here could be?

Thanks in advance!
Anika

var block_break_train = {
      type: "html-keyboard-response",
      trial_duration: 300000,
      stimulus: function(){
        // calculate average accuracy
        var last_trial = jsPsych.data.get().filter({trial_type: 'rdk'}).last().values()[0];
        var trials = jsPsych.data.get().filter({trial_type: 'rdk', block_type: last_trial.block_type, run: last_trial.run, test_part: 'rdk_train'});
        var trials_block = trials.filterCustom(function(trial){
          return trial.trial_number > last_trial.trial_number-block_length && trial.trial_number <= last_trial.trial_number
        });
        var correct_trials = trials_block.filter({RCat: 1});
        var accuracy_train = Math.round(correct_trials.count() / trials_block.count() * 100);
        console.log(accuracy_train);
        // show feedback
          return "<p>You now have max. 5 minutes for a break.</p>" +
          "<p>Your accuracy in the last block was " + accuracy_train + "%.</p>" +
          "<p>Press any key to continue.</p>";
      data: {test_part: 'block_break'}
     },
    };

    var break_procedure_train = {
      timeline: [block_break_train],
      conditional_function: function(){
        var last_trial = jsPsych.data.get().filter({trial_type: 'rdk'}).last().values()[0]; // get last dot trial
        if (last_trial.trial_number % block_length == 0) { // trial_number starts at 1
          no_resp = false;
          timeout_counter = 0;
          return true;  // have a break (have a kitkat)
        } else {
          return false; // don't have a break
        }
      }
    };

[becky-gilbert]

HI @anika-t-l, at first glance I can't see why you're getting this error. Maybe you could post more of your code?

Also, I'm not sure if this is a related issue, but I did notice a syntax error in your block_break_train trial. The curly bracket (to end the stimulus function) and comma after the data parameter should be moved so that it comes after the last line in the stimulus function ("<p>Press any key to continue.</p>"), like this:

var block_break_train = {
  type: "html-keyboard-response",
  trial_duration: 300000,
  stimulus: function(){
    // ...
    return "<p>You now have max. 5 minutes for a break.</p>" +
      "<p>Your accuracy in the last block was " + accuracy_train + "%.</p>" +
      "<p>Press any key to continue.</p>";
  },
  data: {test_part: 'block_break'} 
};

[becky-gilbert]

Hi Anika, no worries!
What version of jsPsych are you using?
And in the console error, I'm guessing there are a few different functions listed, in addition to the createRCat function - do you see any errors and line numbers that correspond to the jsPsych.pluginAPI.convertKeyCharacterToKeyCode function in the jspsych.js file? It might help if you post a screenshot of the error.
The JavaScript function for converting a string to lower case should be written as toLowerCase (uppercase L), so it's possible that there's a typo in that function name in the jspsych.js file (but I'm not sure how that would've happened, since I think we would've caught that before putting together the release...).

[anika-t-l]

Hi Becky,

thank you for your answer!
I am using jsPsych 6.1.0 - I checked the toLowerCase function, but it's spelled correctly, my mistake.
I am attaching a screenshot of the errors from the console.
This is the code from line 600 (on_finish) also indicated by the console:

var dots = {
      type: "rdk",
      /* variable */
      correct_choice: jsPsych.timelineVariable('correct_choice'),
      coherent_direction: jsPsych.timelineVariable('direction'),
      coherence: jsPsych.timelineVariable('coherence'),
      dot_color: jsPsych.timelineVariable('color'),

      /* constant */
      choices: ["X", "M"],
      trial_duration: 2000,
      number_of_dots: 200,
      dot_radius: 7, // radius in pixels (was 8 in PTB)
      dot_life: 10, // number of frames until dot will be replaced (to avoid that ppts are tracking individual dots)
      move_distance: 6, // number of pixel lengths the dot will move in each frame
      aperture_width: 400, // width of the aperture in pixels, for circle diameter (PTB was [6,6] in degrees)
      aperture_center_x: function(){
        return (window.innerWidth/2)  // position aperture in the middle of the screen width
      },
      aperture_center_y: function(){
        return (window.innerHeight/2) // position aperture in the middle of the screen height
      },
      background_color: "black",
      RDK_type: 3,
      aperture_type: 1, // 1 = Circle, 2 = Ellipse, 3 = Square, 4 = Rectangle
      data: jsPsych.timelineVariable('data'), // save extra info to data
      on_finish: function(data) {
        createRCat(data);
        console.log('trial_number: ' + data.trial_number, 'frame_rate: ', data.frame_rate);
      },
      response_ends_trial: false,
      fixation_cross: true,
      fixation_cross_color: "white",
      fixation_cross_thickness: 4,
      fixation_cross_height: 15,
      fixation_cross_width: 15,
      feedback_image_corr: feedback_corr,
      feedback_image_incorr: feedback_incorr,
      on_start: function() {
        document.body.style.cursor = 'none'; // hide the mouse cursor
      }
    };
    
    ```
    

[anika-t-l]

[becky-gilbert]

@anika-t-l I'm guessing the problem is that data.correct_choice is undefined, but it's so odd that this is only true when you don't respond to the break trial with a key press. Can you check this by adding a console.log in the RCat function to print out the trial data before the line that produces the error? E.g.

function createRCat(data) {
  console.log(data);
  // ...
}

[anika-t-l]

I was able to "solve" the problem by introducing a specific choice for the break. I don't know why jsPsych.ALL_KEYS makes a difference to a defined key, but at least now it doesn't crash!