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
}

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

var changeData = function() {
		data = jsPsych.data.getTrialsOfType('text')
		practiceDataCount = 0
		testDataCount = 0
		for (i = 0; i < data.length; i++) {
			if (data[i].trial_id == 'practice_intro') {
				practiceDataCount = practiceDataCount + 1
			} else if (data[i].trial_id == 'test_intro') {
				testDataCount = testDataCount + 1
			}
		}
		if (practiceDataCount >= 1 && testDataCount === 0) {
			//temp_id = data[i].trial_id
			jsPsych.data.addDataToLastTrial({
				exp_stage: "practice"
			})
		} else if (practiceDataCount >= 1 && testDataCount >= 1) {
			//temp_id = data[i].trial_id
			jsPsych.data.addDataToLastTrial({
				exp_stage: "test"
			})
		}
	}
	/* ************************************ */
	/* 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

// task specific variables
var head_left_keys = [72,39]
var head_right_keys = [70,37]
var all_keys = [].concat(head_left_keys, head_right_keys)
window.test_stimuli = [{
	image_url: 'images/ffhff.png',
	data: {
		correct_response: head_right_keys,
		condition: 'incompatible',
		trial_id: 'stim'
	}
}, {
	image_url: 'images/hhfhh.png',
	data: {
		correct_response: head_left_keys,
		condition: 'incompatible',
		trial_id: 'stim'
	}
}, {
	image_url: 'images/hhhhh.png',
	data: {
		correct_response: head_right_keys,
		condition: 'compatible',
		trial_id: 'stim'
	}
}, {
	image_url: 'images/fffff.png',
	data: {
		correct_response: head_left_keys,
		condition: 'compatible',
		trial_id: 'stim'
	}
}];
// define images
$.each(test_stimuli, function() {
  this.image = new Image();
  this.image.src = this.image_url
})
var practice_len = 5 //5
var exp_len = 25 //5
var practice_trials = jsPsych.randomization.repeat(test_stimuli, Math.ceil(practice_len / test_stimuli.length)).slice(0, practice_len);
var test_trials = jsPsych.randomization.repeat(test_stimuli, Math.ceil(exp_len / test_stimuli.length)).slice(0, exp_len);

/* ************************************ */
/* 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. Press <strong>enter</strong> to begin.'
var feedback_instruct_block = {
	type: 'poldrack-text',
	cont_key: [13],
	data: {
		trial_id: "instruction"
	},
	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',
	pages: [
		"<div class = centerbox><p class = block-text>In this experiment you will see five fish in a line. Some are facing left and some right. You need to feed the fish in the middle of the row and to do this you need to mark which way the fish is looking.  <br /> For instance, you might see <img class='in-line-img' src='images/fffff.png' height='20' width='100'/> or <img class='in-line-img' src='images/hhfhh.png' height='20' width='100'/>. Your task is to respond by pressing the key corresponding to the <strong>middle</strong> fish. So if you see <img class='in-line-img' src='images/ffhff.png' height='20' width='100'/> (middle fish looking left) you would press the 'f' key. If the fish was looking right you would press the 'h' key. </p><p class = block-text>After each respond you will get feedback about whether you were correct or not. We will start with a short practice set.</p></div>"
	],
	allow_keys: false,
	data: {
		trial_id: "instruction"
	},
	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
		}
	}
}

function compute_experiment_summary() {
  var trials = jsPsych.data.getTrialsOfType('poldrack-categorize');
  var count = 0;
  var sum_rt = 0;
  var correct_trial_count = 0;
  var correct_rt_count = 0;
  for (var i = 0; i < trials.length; i++) {
    var trial = trials[i]
    if(trial.exp_stage == "test") {
      count++;
      if(trial.correct == true) {
        correct_trial_count++;
        if(trial.rt > -1){
          sum_rt += trial.rt;
          correct_rt_count++;
        }
      }
    }
  }
  return {
    rt: Math.floor(sum_rt / correct_rt_count),
    accuracy: Math.floor(correct_trial_count / count * 100)
  }
}

var end_block = {
	type: 'poldrack-text',
	timing_response: 180000,
	data: {
		trial_id: "end",
		exp_id: 'flanker'
	},
	text: function() {
    var data = compute_experiment_summary()
    return "<p>You responded correctly on "+data.accuracy+"% of the trials. " +
      "Your average response time was <strong>" + data.rt + "ms</strong>. Press enter to complete the "+
      "experiment. Thank you!</p>"
  },
	cont_key: [13],
	timing_post_trial: 0
};

var start_test_block = {
	type: 'poldrack-text',
	data: {
		trial_id: "test_intro"
	},
	timing_response: 180000,
	text: '<div class = centerbox><p class = center-block-text>Done with practice. Starting test.</p><p class = center-block-text>Press <strong>enter</strong> to begin.</p></div>',
	cont_key: [13],
	timing_post_trial: 1000
};

var fixation_block = {
	type: 'poldrack-single-stim',
	stimulus: '<div class = centerbox><div class = fixation>+</div></div>',
	is_html: true,
	data: {
		trial_id: "fixation"
	},
	choices: 'none',
	timing_stim: 500,
	timing_response: 500,
	timing_post_trial: 0,
	on_finish: changeData,
};

//Set up experiment
flanker_experiment = []
flanker_experiment.push(instruction_node);
for (i = 0; i < practice_len; i++) {
	flanker_experiment.push(fixation_block)
  var practice_trial = practice_trials[i]
	var practice_block = {
		type: 'poldrack-categorize',
		stimulus: practice_trial.image,
		key_answer: practice_trial.data.correct_response,
		correct_text: '<div class = centerbox><div style="color:green"; class = center-text>Correct!</div></div>',
		incorrect_text: '<div class = centerbox><div style="color:red"; class = center-text>Incorrect</div></div>',
		timeout_message: '<div class = centerbox><div class = flanker-text>Respond faster</div></div>',
		choices: all_keys,
		data: practice_trial.data,
		timing_feedback_duration: 1000,
		show_stim_with_feedback: false,
		timing_response: 1500,
		timing_post_trial: 500,
		on_finish: function() {
			jsPsych.data.addDataToLastTrial({
				exp_stage: "practice"
			})
		}
	}
	flanker_experiment.push(practice_block)
}
flanker_experiment.push(attention_node)
flanker_experiment.push(start_test_block)

/* define test block */
for (i = 0; i < exp_len; i++) {
  var test_trial = test_trials[i];
	flanker_experiment.push(fixation_block)
	var test_block = {
		type: 'poldrack-categorize',
		stimulus: test_trial.image,
		key_answer: test_trial.data.correct_response,
		correct_text: '<div class = centerbox><div style="color:green"; class = center-text>Correct!</div></div>',
		incorrect_text: '<div class = centerbox><div style="color:red"; class = center-text>Incorrect</div></div>',
		timeout_message: '<div class = centerbox><div class = flanker-text>Respond faster!</div></div>',
		choices: all_keys,
		data: test_trial.data,
		timing_feedback_duration: 1000,
		timing_response: 1500,
		show_stim_with_feedback: false,
		timing_post_trial: 500,
		on_finish: function() {
			jsPsych.data.addDataToLastTrial({
				exp_stage: "test"
			})
		}
	}
	flanker_experiment.push(test_block)
}
flanker_experiment.push(attention_node)
flanker_experiment.push(post_task_block)
flanker_experiment.push(end_block)