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¶

In addition to the parameters available in all plugins, this plugin accepts the following parameters. 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 a path to an image file.
choices	array of strings	`jsPsych.ALL_KEYS`	This array contains the key(s) that the subject is allowed to press in order to respond to the stimulus. Keys should be specified as characters (e.g., `'a'`, `'q'`, `' '`, `'Enter'`, `'ArrowDown'`) - see this page and this page (event.key column) for more examples. Any key presses that are not listed in the array will be ignored. The default value of `jsPsych.ALL_KEYS` means that all keys will be accepted as valid responses. Specifying `jsPsych.NO_KEYS` will mean that no responses are allowed.
key_answer	string	undefined	The key character indicating the correct response.
text_answer	string	""	A text label that describes the 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	500	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	null	This string can contain HTML markup. Any content here will be displayed below the stimulus or the end of the animation depending on the allow_response_before_complete parameter. 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).
feedback_duration	numeric	2000	How long to show the feedback (milliseconds).
render_on_canvas	boolean	true	If true, the images will be drawn onto a canvas element. This prevents a blank screen (white flash) between consecutive images in some browsers, like Firefox and Edge. If false, the image will be shown via an img element, as in previous versions of jsPsych.

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	array	Array of stimuli displayed in the trial. This will be encoded as a JSON string when data is saved using the `.json()` or `.csv()` functions.
response	string	Indicates which key the subject pressed.
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¶

Basic example

Code

var animation_trial = {
    type: 'categorize-animation',
    stimuli: [
        'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_1.jpg', 
        'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_2.jpg', 
        'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_3.jpg', 
        'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_4.jpg'
    ],
    prompt: `Press the P or Q key.`,
    choices: ['p', 'q'],
    key_answer: 'q', 
};

Demo

Open demo in new tab

Giving feedback with %ANS% string

Code

var images = [
    'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_1.jpg', 
    'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_2.jpg', 
    'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_3.jpg', 
    'https://cdn.jsdelivr.net/gh/jspsych/jsPsych@6.3.1/examples/img/happy_face_4.jpg'
];

var animation_trial = {
    type: 'categorize-animation',
    stimuli: images,
    choices: ['p', 'q'],
    prompt: `Press the P or Q key.`,
    key_answer: 'q', 
    text_answer: 'Dax', // the label for the sequence is 'Dax'
    correct_text: 'Correct! This was a %ANS%.',
    incorrect_text: 'Incorrect. This was a %ANS%.'
};

Demo

Open demo in new tab