experiment.js

/* ************************************ */
/* Define helper functions */
/* ************************************ */
function evalAttentionChecks() {
  var check_percent = 1
  if (run_attention_checks) {
    var attention_check_trials = jsPsych.data.getTrialsOfType('attention-check')
    var checks_passed = 0
    for (var i = 0; i < attention_check_trials.length; i++) {
      if (attention_check_trials[i].correct === true) {
        checks_passed += 1
      }
    }
    check_percent = checks_passed / attention_check_trials.length
  }
  return check_percent
}

function assessPerformance() {
	/* Function to calculate the "credit_var", which is a boolean used to
	credit individual experiments in expfactory. 
	 */
	var experiment_data = jsPsych.data.getTrialsOfType('poldrack-single-stim')
	experiment_data = experiment_data.concat(jsPsych.data.getTrialsOfType('poldrack-categorize'))
	var missed_count = 0
	var trial_count = 0
	var rt_array = []
	var rt = 0
		//record choices participants made
	var choice_counts = {}
	choice_counts[-1] = 0
	for (var k = 0; k < choices.length; k++) {
    choice_counts[choices[k]] = 0
  }
	for (var i = 0; i < experiment_data.length; i++) {
		if (experiment_data[i].possible_responses != 'none') {
			trial_count += 1
			rt = experiment_data[i].rt
			key = experiment_data[i].key_press
			choice_counts[key] += 1
			if (rt == -1) {
				missed_count += 1
			} else {
				rt_array.push(rt)
			}
		}

	}
	//calculate average rt
  var avg_rt = -1
  if (rt_array.length !== 0) {
    avg_rt = math.median(rt_array)
  } 
		//calculate whether response distribution is okay
	var responses_ok = true
	Object.keys(choice_counts).forEach(function(key, index) {
		if (choice_counts[key] > trial_count * 0.85) {
			responses_ok = false
		}
	})
	var missed_percent = missed_count/trial_count
	credit_var = (missed_percent < 0.4 && avg_rt > 200 && responses_ok)
	jsPsych.data.addDataToLastTrial({"credit_var": credit_var})
}

var randomDraw = function(lst) {
  var index = Math.floor(Math.random() * (lst.length))
  return lst[index]
}

var getInstructFeedback = function() {
  return '<div class = centerbox><p class = center-block-text>' + feedback_instruct_text +
    '</p></div>'
}

// Task Specific Functions
var getKeys = function(obj) {
  var keys = [];
  for (var key in obj) {
    keys.push(key);
  }
  return keys
}

var genStims = function(n) {
  stims = []
  for (var i = 0; i < n; i++) {
    var number = randomDraw('12346789')
    var color = randomDraw(['orange', 'blue'])
    var stim = {
      number: parseInt(number),
      color: color
    }
    stims.push(stim)
  }
  return stims
}

//Sets the cue-target-interval for the cue block
var setCTI = function() {
  return randomDraw([100, 900])
}

var getCTI = function() {
  return CTI
}

/* Index into task_switches using the global var current_trial. Using the task_switch and cue_switch
change the task. If "stay", keep the same task but change the cue based on "cue switch". 
If "switch new", switch to the task that wasn't the current or last task, choosing a random cue. 
If "switch old", switch to the last task and randomly choose a cue.
*/
var setStims = function() {
  var tmp;
  switch (task_switches[current_trial].task_switch) {
    case "stay":
      if (curr_task == "na") {
        tmp = curr_task
        curr_task = randomDraw(getKeys(tasks))
      }
      if (task_switches[current_trial].cue_switch == "switch") {
        cue_i = 1 - cue_i
      }
      break
    case "switch_new":
      cue_i = randomDraw([0, 1])
      if (last_task == "na") {
        tmp = curr_task
        curr_task = randomDraw(getKeys(tasks).filter(function(x) {
          return (x != curr_task)
        }))
        last_task = tmp
      } else {
        tmp = curr_task
        curr_task = getKeys(tasks).filter(function(x) {
          return (x != curr_task & x != last_task)
        })[0]
        last_task = tmp
      }
      break
    case "switch_old":
      cue_i = randomDraw([0, 1])
      if (last_task == "na") {
        tmp = curr_task
        curr_task = randomDraw(getKeys(tasks).filter(function(x) {
          return (x != curr_task)
        }))
        last_task = tmp
      } else {
        tmp = curr_task
        curr_task = last_task
        last_task = tmp
      }
      break

  }
  curr_cue = tasks[curr_task].cues[cue_i]
  curr_stim = stims[current_trial]
  current_trial = current_trial + 1
  CTI = setCTI()
}

var getCue = function() {
  var cue_html = '<div class = upperbox><div class = "center-text" >' + curr_cue +
    '</div></div><div class = lowerbox><div class = fixation>+</div></div>'
  return cue_html
}

var getStim = function() {
  var stim_html = '<div class = upperbox><div class = "center-text" >' + curr_cue +
    '</div></div><div class = lowerbox><div class = "center-text" style=color:' + curr_stim.color +
    ';>' + curr_stim.number + '</div>'
  return stim_html
}

//Returns the key corresponding to the correct response for the current
// task and stim
var getResponse = function() {
  switch (curr_task) {
    case 'color':
      if (curr_stim.color == 'orange') {
        return response_keys.key[0]
      } else {
        return response_keys.key[1]
      }
      break;
    case 'magnitude':
      if (curr_stim.number > 5) {
        return response_keys.key[0]
      } else {
        return response_keys.key[1]
      }
      break;
    case 'parity':
      if (curr_stim.number % 2 === 0) {
        return response_keys.key[0]
      } else {
        return response_keys.key[1]
      }
  }
}


/* Append gap and current trial to data and then recalculate for next trial*/
var appendData = function() {
  var trial_num = current_trial - 1 //current_trial has already been updated with setStims, so subtract one to record data
  var task_switch = task_switches[trial_num]
  jsPsych.data.addDataToLastTrial({
    cue: curr_cue,
    stim_color: curr_stim.color,
    stim_number: curr_stim.number,
    task: curr_task,
    task_switch: task_switch.task_switch,
    cue_switch: task_switch.cue_switch,
    trial_num: trial_num
  })
}

/* ************************************ */
/* Define experimental variables */
/* ************************************ */
// generic task variables
var run_attention_checks = false
var attention_check_thresh = 0.45
var sumInstructTime = 0 //ms
var instructTimeThresh = 0 ///in seconds
var credit_var = true

// task specific variables
var response_keys = jsPsych.randomization.repeat([{
  key: 77,
  key_name: 'M'
}, {
  key: 90,
  key_name: 'Z'
}], 1, true)
var choices = response_keys.key
var practice_length = 60
var test_length = 440

//set up block stim. correct_responses indexed by [block][stim][type]
var tasks = {
  color: {
    task: 'color',
    cues: ['Color', 'Orange-Blue']
  },
  parity: {
    task: 'parity',
    cues: ['Parity', 'Odd-Even']
  },
  magnitude: {
    task: 'magnitude',
    cues: ['Magnitude', 'High-Low']
  }
}

var task_switch_types = ["stay", "switch_new", "switch_old"]
var cue_switch_types = ["stay", "switch"]
var task_switches = []
for (var t = 0; t < task_switch_types.length; t++) {
  for (var c = 0; c < cue_switch_types.length; c++) {
    task_switches.push({
      task_switch: task_switch_types[t],
      cue_switch: cue_switch_types[c]
    })
  }
}
var task_switches = jsPsych.randomization.repeat(task_switches, practice_length / 6)
var practiceStims = genStims(practice_length)
var testStims = genStims(test_length)
var stims = practiceStims
var curr_task = randomDraw(getKeys(tasks))
var last_task = 'na' //object that holds the last task, set by setStims()
var curr_cue = 'na' //object that holds the current cue, set by setStims()
var cue_i = randomDraw([0, 1]) //index for one of two cues of the current task
var curr_stim = 'na' //object that holds the current stim, set by setStims()
var current_trial = 0
var CTI = 0 //cue-target-interval
var exp_stage = 'practice' // defines the exp_stage, switched by start_test_block

var task_list = '<ul><li><strong>Color</strong> or <strong>Orange-Blue</strong>: Press the ' +
  response_keys.key_name[0] + ' key if orange and the ' + response_keys.key_name[1] +
  ' key if blue.' +
  '</li><li><strong>Parity</strong> or <strong>Odd-Even</strong>: Press the ' + response_keys.key_name[
    0] + ' key if even and the ' + response_keys.key_name[1] + ' key if odd.' +
  '</li><li><strong>Magnitude</strong> or <strong>High-Low</strong>: Press the ' + response_keys.key_name[
    0] + ' key if the number is greater than 5 and the ' + response_keys.key_name[1] +
  ' key if less than 5.</li></ul>'

var prompt_task_list = '<ul><li><strong>Color</strong> or <strong>Orange-Blue</strong>: ' +
  response_keys.key_name[0] + ' if orange and ' + response_keys.key_name[1] + ' if blue.' +
  '</li><li><strong>Parity</strong> or <strong>Odd-Even</strong>: ' + response_keys.key_name[0] +
  ' if even and ' + response_keys.key_name[1] + ' if odd.' +
  '</li><li><strong>Magnitude</strong> or <strong>High-Low</strong>: ' + response_keys.key_name[0] +
  ' if >5 and ' + response_keys.key_name[1] + ' if <5.</li></ul>'



/* ************************************ */
/* Set up jsPsych blocks */
/* ************************************ */
// Set up attention check node
var attention_check_block = {
  type: 'attention-check',
  data: {
    trial_id: "attention_check"
  },
  timing_response: 180000,
  response_ends_trial: true,
  timing_post_trial: 200
}

var attention_node = {
  timeline: [attention_check_block],
  conditional_function: function() {
    return run_attention_checks
  }
}

//Set up post task questionnaire
var post_task_block = {
   type: 'survey-text',
   data: {
       trial_id: "post task questions"
   },
   questions: ['<p class = center-block-text style = "font-size: 20px">Please summarize what you were asked to do in this task.</p>',
              '<p class = center-block-text style = "font-size: 20px">Do you have any comments about this task?</p>'],
   rows: [15, 15],
   columns: [60,60]
};

/* define static blocks */
var feedback_instruct_text =
  'Welcome to the experiment. This experiment will take about 24 minutes. Press <strong>enter</strong> to begin.'
var feedback_instruct_block = {
  type: 'poldrack-text',
  data: {
    trial_id: "instruction"
  },
  cont_key: [13],
  text: getInstructFeedback,
  timing_post_trial: 0,
  timing_response: 180000
};
/// This ensures that the subject does not read through the instructions too quickly.  If they do it too quickly, then we will go over the loop again.
var instructions_block = {
  type: 'poldrack-instructions',
  data: {
    trial_id: "instruction"
  },
  pages: [
    '<div class = centerbox><p class = block-text>In this experiment you will have to respond to a sequence of colored numbers by pressing the "M" and "Z" keys. How you respond to the numbers will depend on the current task, which can change every trial.</p><p class = block-text>For instance, on some trials you will have to indicate whether the number is odd or even, and on other trials you will indicate whether the number is orange or blue. Each trial will start with a cue telling you which task to do on that trial.</p></div>',
    '<div class = centerbox><p class = block-text>The cue before the number will be a word indicating the task. There will be six different cues indicating three different tasks. Thee cues and tasks are described below:</p>' +
    task_list +
    '<p class = block-text>Practice will start after you end instructions.</p></div>'
  ],
  allow_keys: false,
  show_clickable_nav: true,
  timing_post_trial: 1000
};

var instruction_node = {
  timeline: [feedback_instruct_block, instructions_block],
  /* This function defines stopping criteria */
  loop_function: function(data) {
    for (i = 0; i < data.length; i++) {
      if ((data[i].trial_type == 'poldrack-instructions') && (data[i].rt != -1)) {
        rt = data[i].rt
        sumInstructTime = sumInstructTime + rt
      }
    }
    if (sumInstructTime <= instructTimeThresh * 1000) {
      feedback_instruct_text =
        'Read through instructions too quickly.  Please take your time and make sure you understand the instructions.  Press <strong>enter</strong> to continue.'
      return true
    } else if (sumInstructTime > instructTimeThresh * 1000) {
      feedback_instruct_text =
        'Done with instructions. Press <strong>enter</strong> to continue.'
      return false
    }
  }
}
var end_block = {
  type: 'poldrack-text',
  data: {
    trial_id: "end",
    exp_id: 'threebytwo'
  },
  text: '<div class = centerbox><p class = center-block-text>Thanks for completing this task!</p><p class = center-block-text>Press <strong>enter</strong> to continue.</p></div>',
  cont_key: [13],
  timing_response: 180000,
  on_finish: assessPerformance
};

var start_practice_block = {
  type: 'poldrack-text',
  data: {
    trial_id: "practice_intro"
  },
  text: '<div class = centerbox><p class = center-block-text>Starting with some practice. </p><p class = center-block-text>Press <strong>enter</strong> to continue.</p></div>',
  cont_key: [13]
};

var start_test_block = {
  type: 'poldrack-text',
  data: {
    trial_id: "test_intro"
  },
  text: '<div class = centerbox><p class = center-block-text>Practice completed. Starting test.</p><p class = center-block-text>Press <strong>enter</strong> to begin.</p></div>',
  on_finish: function() {
    current_trial = 0
    stims = testStims
    task_switches = jsPsych.randomization.repeat(task_switches, test_length / 6)
  },
  timing_post_trial: 1000
}

/* define practice and test blocks */
var setStims_block = {
  type: 'call-function',
  data: {
    trial_id: "set_stims"
  },
  func: setStims,
  timing_post_trial: 0
}

var fixation_block = {
  type: 'poldrack-single-stim',
  stimulus: '<div class = upperbox><div class = fixation>+</div></div><div class = lowerbox><div class = fixation>+</div></div>',
  is_html: true,
  choices: 'none',
  data: {
    trial_id: "fixation"
  },
  timing_post_trial: 0,
  timing_stim: 500,
  timing_response: 500,
  prompt: '<div class = promptbox>' + prompt_task_list + '</div>',
  on_finish: function() {
    jsPsych.data.addDataToLastTrial({
      exp_stage: exp_stage
    })
  }
}

var cue_block = {
  type: 'poldrack-single-stim',
  stimulus: getCue,
  is_html: true,
  choices: 'none',
  data: {
    trial_id: 'cue'
  },
  timing_response: getCTI,
  timing_stim: getCTI,
  timing_post_trial: 0,
  prompt: '<div class = promptbox>' + prompt_task_list + '</div>',
  on_finish: function() {
    jsPsych.data.addDataToLastTrial({
      exp_stage: exp_stage
    })
    appendData()
  }
};

var practice_block = {
  type: 'poldrack-categorize',
  stimulus: getStim,
  is_html: true,
  key_answer: getResponse,
  correct_text: '<div class = centerbox><div style="color:green"; class = center-text>Correct!</p></div><div class = promptbox>' +
    prompt_task_list + '</div>',
  incorrect_text: '<div class = centerbox><div style="color:red"; class = center-text>Incorrect</p></div><div class = promptbox>' +
    prompt_task_list + '</div>',
  timeout_message: '<div class = centerbox><div class = center-text>Too Slow</div></div><div class = promptbox>' +
    prompt_task_list + '</div>',
  choices: choices,
  data: {
    trial_id: 'stim',
    exp_stage: "practice"
  },
  timing_feedback_duration: 1000,
  show_stim_with_feedback: false,
  timing_response: 2000,
  timing_stim: 1000,
  timing_post_trial: 0,
  prompt: '<div class = promptbox>' + prompt_task_list + '</div>',
  on_finish: appendData
}

var test_block = {
  type: 'poldrack-single-stim',
  stimulus: getStim,
  is_html: true,
  key_answer: getResponse,
  choices: choices,
  data: {
    trial_id: 'stim',
    exp_stage: 'test'
  },
  timing_post_trial: 0,
  timing_response: 2000,
  timing_stim: 1000,
  prompt: '<div class = promptbox>' + prompt_task_list + '</div>',
  on_finish: function(data) {
    appendData()
    correct_response = getResponse()
    correct = false
    if (data.key_press === correct_response) {
      correct = true
    }
    jsPsych.data.addDataToLastTrial({
      'correct_response': correct_response,
      'correct': correct
    })
  }
}

var gap_block = {
  type: 'poldrack-single-stim',
  stimulus: ' ',
  is_html: true,
  choices: 'none',
  data: {
    trial_id: 'gap',
    exp_stage: 'practice'
  },
  timing_response: 500,
  timing_stim: 0,
  timing_post_trial: 0,
  prompt: '<div class = promptbox>' + prompt_task_list + '</div>',
};


/* create experiment definition array */
var threebytwo_experiment = [];
threebytwo_experiment.push(instruction_node);
threebytwo_experiment.push(start_practice_block);
for (var i = 0; i < practice_length; i++) {
  threebytwo_experiment.push(setStims_block)
  threebytwo_experiment.push(fixation_block)
  threebytwo_experiment.push(cue_block);
  threebytwo_experiment.push(practice_block);
  threebytwo_experiment.push(gap_block);
}
threebytwo_experiment.push(attention_node)
threebytwo_experiment.push(start_test_block)
for (var i = 0; i < test_length; i++) {
  threebytwo_experiment.push(setStims_block)
  threebytwo_experiment.push(fixation_block)
  threebytwo_experiment.push(cue_block);
  threebytwo_experiment.push(test_block);
}
threebytwo_experiment.push(attention_node)
threebytwo_experiment.push(post_task_block)
threebytwo_experiment.push(end_block)