show pressed keys while picture is being presented by image-keyboard-response plugin

[SRJongman]

Hi,

I have adapted the image-keyboard-response plugin to allow for multiple keys to be pressed (i.e. to allow for typing in the name of picture) and I store each pressed key and each RT in arrays. Is it possible to show the response while the participant is typing and the picture is still on? I added a textbox which appears below the picture but nothing happens when I type (even though information about keys/rts is saved). Is there anyway I can show which keys are being pressed, during the trial? I have added the plugin.trial code I have at the moment.

Kind regards,

Suzanne

plugin.trial = function(display_element, trial) {

    // display stimulus
    var html = '<img src="'+trial.stimulus+'" id="jspsych-image-keyboard-response-stimulus" style="';
    if(trial.stimulus_height !== null){
      html += 'height:'+trial.stimulus_height+'px; '
      if(trial.stimulus_width == null && trial.maintain_aspect_ratio){
        html += 'width: auto; ';
      }
    }
    if(trial.stimulus_width !== null){
      html += 'width:'+trial.stimulus_width+'px; '
      if(trial.stimulus_height == null && trial.maintain_aspect_ratio){
        html += 'height: auto; ';
      }
    }
    html +='"></img>';
    html += '</br>';

    // add prompt
    if (trial.prompt !== null){
      html += trial.prompt;
    }

    html += '<input type="text" id="input"></input>';

    // render
    display_element.innerHTML = html;

    var rt = [];
    var key = [];

    // function to end trial when it is time
    var end_trial = function() {

      // kill any remaining setTimeout handlers
      jsPsych.pluginAPI.clearAllTimeouts();

      // kill keyboard listeners
      if (typeof keyboardListener !== 'undefined') {
        jsPsych.pluginAPI.cancelKeyboardResponse(keyboardListener);
      }

      // gather the data to store for the trial
      var trial_data = {
        "rt": JSON.stringify(rt),
        "stimulus": trial.stimulus,
        "key": JSON.stringify(key)
      };

      // clear the display
      display_element.innerHTML = '';

      // move on to the next trial
      jsPsych.finishTrial(trial_data);
    };

    // function to handle responses by the subject
    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-image-keyboard-response-stimulus').className += ' responded';

      rt.push(info.rt);
      key.push(jsPsych.pluginAPI.convertKeyCodeToKeyCharacter(info.key));

     if (trial.response_ends_trial) {
        end_trial();
      }
    };

    // start the response listener
    if (trial.choices != jsPsych.NO_KEYS) {
      var keyboardListener = jsPsych.pluginAPI.getKeyboardResponse({
        callback_function: after_response,
        valid_responses: trial.choices,
        rt_method: 'performance',
        persist: true,
        allow_held_key: false
      });
    }

    // hide stimulus if stimulus_duration is set
    if (trial.stimulus_duration !== null) {
      jsPsych.pluginAPI.setTimeout(function() {
        display_element.querySelector('#jspsych-image-keyboard-response-stimulus').style.visibility = 'hidden';
      }, trial.stimulus_duration);
    }

    // end trial if trial_duration is set
    if (trial.trial_duration !== null) {
      jsPsych.pluginAPI.setTimeout(function() {
        end_trial();
      }, trial.trial_duration);
    }

  };

  return plugin;
})();

[becky-gilbert]

FYI @SRJongman, I just edited your post to make the code easier to read (see #1113) 😃

[SRJongman]

That does look better 😃