jsPsych/docs/markdown_docs/plugins/jspsych-categorize-animation.md
2014-10-16 10:11:02 -04:00

4.9 KiB

jspsych-categorize-animation

The categorize animation plugin shows a sequence of images at a specified frame rate. The subject responds by pressing a key. Feedback indicating the correctness of the response is given.

Parameters

This table lists the parameters associated with this plugin. Parameters with a default value of undefined must be specified. Other parameters can be left unspecified if the default value is acceptable.

Parameter Type Default Value Description
stimuli array undefined Each element of the array is an array containing strings. The strings are paths to image files. Each array of strings specifies a single sequence, and each sequence will be its own trial. The length of this array determines the total number of trials.
key_answer array undefined Each element of the array is a numeric key code indicating the correct response for the corresponding trial. The length of this array should match the stimuli array.
choices array undefined This array contains the keys that the subject is allowed to press in order to respond to the stimulus. Keys can be specified as their numeric key code or as characters (e.g. 'a', 'q').
text_answer array "" Array of strings representing a label that is associated with each correct answer. Used in conjunction with the correct_text and incorrect_text parameters.
correct_text string "Correct." String to show when the correct answer is given. Can contain HTML formatting. The special string %ANS% can be used within the string. If present, the plugin will put the text_answer for the trial in place of the %ANS% string (see example below).
incorrect_text string "Wrong." String to show when the wrong answer is given. Can contain HTML formatting. The special string %ANS% can be used within the string. If present, the plugin will put the text_answer for the trial in place of the %ANS% string (see example below).
frame_time numeric 250 How long to display each image (in milliseconds).
sequence_reps numeric 1 How many times to show the entire sequence.
allow_response_before_complete boolean false If true, the subject can respond before the animation sequence finishes.
prompt string "" This string can contain HTML markup. Any content here will be displayed below the stimulus. The intention is that it can be used to provide a reminder about the action the subject is supposed to take (e.g. which key to press).
timing_feedback_duration numeric 2000 How long to show the feedback (milliseconds).

Data Generated

In addition to the default data collected by all plugins, this plugin collects the following data for each trial.

Name Type Value
stimulus string The first image in the animation sequence for this trial
key_press numeric Indicates which key the subject pressed. The value is the numeric key code corresponding to the subject's response.
rt numeric The response time in milliseconds for the subject to make a response. The time is measured from when the stimulus first appears on the screen until the subject's response.
correct boolean true if the subject got the correct answer, false otherwise.

Examples

These examples show how to define a block using the categorize-animation plugin to achieve various goals.

Basic example

// declare variables to hold animation sequences
var animation_sequence_1 = ["img/face_1.jpg", "img/face_2.jpg", "img/face_3.jpg", "img/face_4.jpg", "img/face_3.jpg", "img/face_2.jpg"];
var animation_sequence_2 = ["img/face_3.jpg", "img/face_2.jpg", "img/face_4.jpg", "img/face_1.jpg"];

// create animation block for jspsych
var animation_block = {
    type: 'categorize-animation',
    stimuli: [animation_sequence_1, animation_sequence_2],
	choices: [80, 81], // 80 = 'p', 81 = 'q'
	key_answer: [81, 81], // correct answer is 'q' for both trials
};

Giving feedback with %ANS% string


// declare variables to hold animation sequences
var animation_sequence_1 = ["img/face_1.jpg", "img/face_2.jpg", "img/face_3.jpg", "img/face_4.jpg", "img/face_3.jpg", "img/face_2.jpg"];
var animation_sequence_2 = ["img/face_3.jpg", "img/face_2.jpg", "img/face_4.jpg", "img/face_1.jpg"];

// create animation block for jspsych
var animation_block = {
    type: 'categorize-animation',
    stimuli: [animation_sequence_1, animation_sequence_2],
	choices: [80, 81], // 80 = 'p', 81 = 'q'
	key_answer: [81, 81], // correct answer is 'q' for both trials,
	text_answer: ['Dax', 'Dax'], // the label for the sequence is 'Dax'
	correct_text: 'Correct! This was a %ANS%.',
	incorrect_text: 'Incorrect. This was a %ANS%.'
};