Looping an incorrect trial

[rbruno1]

Hi. So my experiment plays a word, and the participant has to write the word they heard. I have implemented a feedback trial, but i would like to loop the trial if the participant guesses wrong. here is what i've got. Just tell me where i went wrong. The loop function isn't executing.

const practice_trial_3 = {
  timeline: [
  {type: 'audio-keyboard-response',
  stimulus: 'GatingStimuli_Dollar.wav',
  response_allowed_while_playing: false,
  trial_ends_after_audio: true,
  post_trial_gap: 250
  },
  { type:'html-button-response',
    stimulus: ["Press OK to move on, or Listen again to replay the sound"],
    choices: ['OK', 'Listen again'],
    post_trial_gap: 500,
    on_start: function(trial) {
      if (repeated) {
        trial.choices = ['OK'];
      }
    }
  }],
  loop_function: function(data){
    if(data.values()[1].response == 1
    && !repeated){
      repeated = true;
      return true;
    } else {
      repeated = false;
      return false;
    }
  }
};

const practice_response_trial_3 = {
  type: 'survey-text',
  questions: [
    {prompt: "What word was she about to say? If you don't know or didnt hear, then type NR for no response"}
    ],
  post_trial_gap: 500,
  data: {
    task: 'response',
    correct_response: 'dollar'
  },
  on_finish: function(data) {
    data.correct = data.response.Q0.toLowerCase() == data.correct_response;
      },
}
      
**const practice_feedback_3 = {
  type: 'html-button-response',
  choices: ['Next'],
  stimulus: function(){
    var last_trial_correct = jsPsych.data.get().last(1).values()[0].correct;
    if(last_trial_correct){
      return "<p>Correct! You are ready for the real experiment.</p>"; 
    } else {
      return "<p>You answered incorrectly. Let's try that one again.</p>"; 
    }
  },
      loop_function: function(data){
        if(last_trial_correct){
            return true;
        } else {
            return false;
        }
    }
}**

[rbruno1]

so i got it to work, but the loop only executes once. how do i make it loop until there is a correct response? here is the updated code:

const practice_trial_3 = {
  timeline: [
  {type: 'audio-keyboard-response',
  stimulus: 'GatingStimuli_Dollar.wav',
  response_allowed_while_playing: false,
  trial_ends_after_audio: true,
  post_trial_gap: 250
  },
  { type:'html-button-response',
    stimulus: ["Press OK to move on, or Listen again to replay the sound"],
    choices: ['OK', 'Listen again'],
    post_trial_gap: 500,
    on_start: function(trial) {
      if (repeated) {
        trial.choices = ['OK'];
      }
    }
  }]
}

const practice_response_trial_3 = {
  type: 'survey-text',
  questions: [
    {prompt: "What word was she about to say? If you don't know or didnt hear, then type NR for no response"}
    ],
  post_trial_gap: 500,
  data: {
    task: 'response',
    correct_response: 'dollar'
  },
  on_finish: function(data) {
    data.correct = data.response.Q0.toLowerCase() == data.correct_response;
      },
}
      
const practice_feedback_3 = {
  type: 'html-button-response',
  choices: ['Next'],
  stimulus: function(){
    // The feedback stimulus is a dynamic parameter because we can't know in advance whether
    // the stimulus should be 'correct' or 'incorrect'.
    // Instead, this function will check the accuracy of the last response and use that information to set
    // the stimulus value on each trial.
    var last_trial_correct = jsPsych.data.get().last(1).values()[0].correct;
    if(last_trial_correct){
      return "<p>Correct! You are ready for the real experiment.</p>"; // the parameter value has to be returned from the function
    } else {
      return "<p>You answered incorrectly. Let's try that one again.</p>"; // the parameter value has to be returned from the function
    }
  }
}
const practice_feedback_3_loop = {
        timeline:[practice_trial_3,practice_response_trial_3,practice_feedback_3],
      loop_function: function(data){
        var last_trial_correct = jsPsych.data.get().first(1).values()[0].correct;
        if(last_trial_correct){
            return true;
        } else {
            return false;
        }}}

[becky-gilbert]

Hi @rbruno1, the first function that you're using to get the data in your loop function here:

var last_trial_correct = jsPsych.data.get().first(1).values()[0].correct;

is getting the very first trial in the whole experiment (see docs for first and last here).

In your loop function, you want to check the last set of practice trials to see if the response was correct. However, you don't want to use the very last trial in the practice_feedback_3_loop timeline, because that's the practice_feedback_3 trial, and there's no response accuracy stored in that trial. So instead you can get the last 2 trials from the timeline (practice_response_trial_3 and practice_feedback_3), and then get the first of those two trials (practice_response_trial_3) by getting the data values and indexing the resulting array with 0. Then you'll have the data from the last response trial, so you can look at the correct value to determine whether or not the last response was correct.

const practice_feedback_3_loop = {
  timeline:[practice_trial_3,practice_response_trial_3,practice_feedback_3],
  loop_function: function(data){
    // get the last 2 trials with last(2), then get data values from the first of those two trials with values()[0],
    // then check if the response from that trial was correct
    var last_trial_correct = jsPsych.data.get().last(2).values()[0].correct;
    if(last_trial_correct){
      return true;
    } else {
      return false;
     }
  }
}

One way to check that this is working is to use a console.log to look at the trial data in your loop function. The code below should print out the data from the last response trial.

const practice_feedback_3_loop = {
  timeline:[practice_trial_3,practice_response_trial_3,practice_feedback_3],
  loop_function: function(data){
    console.log(jsPsych.data.get().last(2).values()[0]); // check that this data is from the last response trial
    var last_trial_correct = jsPsych.data.get().last(2).values()[0].correct;
    if(last_trial_correct){
      return false; // if correct then don't run the timeline again
    } else {
      return true; // if incorrect then loop again
     }
  }
}

I hope this helps!

[rbruno1]

this is causing an infinite loop. It is supposed to only loop when the participant answers incorrectly. it is looping even after correct responses.

[becky-gilbert]

@rbruno1 you're right, sorry! I got the true and false the wrong way around in the loop_function. If the last trial was correct then the timeline SHOULD NOT loop again (return false), otherwise the timeline SHOULD loop again (return true). I'll edit my code above.

[becky-gilbert]

FYI, I've edited your posts to make the code easier to read. You need to use 3 backticks (`) rather than single quotes (') to get the nice code formatting. See here: #1113 😃

[rbruno1]

thank you! also, it only loops once - is there a way to loop it until the participant gets the answer correct?