exp-lookit-calibration

Overview

Frame to do calibration for looking direction. Shows a small video/image in a sequence of locations so you’ll have video of the child looking to those locations at known times.

The attention-grabber can be either a small video or an image (see examples below of each). Images can be animated (spinning or bouncing).

The image or video can be displayed at center, left, or right of the screen. You can specify the sequence of positions or use the default [‘center’, ‘left’, ‘right’, ‘center’]. Each time it moves, the video (if any) and audio restart, and an event is recorded with the location and time (and time relative to any video recording) of the segment start.

What it looks like

Recording

Generally you will want to have webcam video of this frame. You can set doRecording to true to make a video clip just for this frame. Recording will begin at the same time the first calibration stimulus is shown. Alternately, you can use session-level recording (set startSessionRecording to true on this or a previous frame). If either type of recording is starting on this frame, it waits until recording starts to display the first calibration segment.

Fullscreen display

This frame is displayed fullscreen, to match the frames you will likely want to compare looking behavior on. If the participant leaves fullscreen, that will be recorded as an event, and a large “return to fullscreen” button will be displayed. Don’t use video coding from any intervals where the participant isn’t in fullscreen mode - the position of the attention-grabbers won’t be as expected.

If the frame before this is not fullscreen, that frame needs to include a manual “next” button so that there’s a user interaction event to trigger fullscreen mode. (Browsers don’t allow us to switch to FS without a user event.)

Specifying where files are

Several of the parameters for this frame can be specified either by providing a list of full URLs and file types, or by providing just a filename that will be interpreted relative to the baseDir. See the expand-assets mixin mixin that this frame uses.

More general functionality

Below is information specific to this particular frame. There may also be available parameters, events recorded, and data collected that come from the following more general sources:

• the base frame (things all frames do)

• video-record mixin

• expand-assets mixin

Examples

This frame will show an image at center, left, and right, along with chimes each time.

"calibration-with-image": {
    "kind": "exp-lookit-calibration",
    "baseDir": "https://www.mit.edu/~kimscott/placeholderstimuli/",
    "audioTypes": [
        "ogg",
        "mp3"
    ],
    "videoTypes": [
        "webm",
        "mp4"
    ],
    "calibrationImage": "peekaboo_remy.jpg",
    "calibrationLength": 3000,
    "calibrationPositions": [
        "center",
        "left",
        "right"
    ],
    "calibrationAudio": "chimes",
    "calibrationImageAnimation": "spin"
}

This frame will show a small video at center, left, and right, along with chimes each time.

"calibration-with-video": {
    "kind": "exp-lookit-calibration",
    "baseDir": "https://www.mit.edu/~kimscott/placeholderstimuli/",
    "audioTypes": [
        "ogg",
        "mp3"
    ],
    "videoTypes": [
        "webm",
        "mp4"
    ],
    "calibrationLength": 3000,
    "calibrationPositions": [
        "center",
        "left",
        "right"
    ],
    "calibrationAudio": "chimes",
    "calibrationVideo": "attentiongrabber"
}

Parameters

doRecording [Boolean | true]

Whether to do any video recording during this frame. Default true. Set to false for e.g. last frame where just doing an announcement.

backgroundColor [String | white]

Color of background. See CSS specs for acceptable syntax: can use color names (‘blue’, ‘red’, ‘green’, etc.), or rgb hex values (e.g. ‘#800080’ - include the ‘#’)

calibrationLength [Number | 3000]

Length of each calibration segment in ms

calibrationPositions [Array | ['center', 'left', 'right', 'center']]

Ordered list of positions to show calibration segment in. Options are “center”, “left”, “right”. Ignored if calibrationLength is 0.

calibrationAudio [String or Array | []]

Audio to play when the attention-grabber is placed at each location (will be played once from the start, but cut off if it’s longer than calibrationLength).

This can either be an array of {src: ‘url’, type: ‘MIMEtype’} objects for calibration audio, or just a string to use the full URLs based on baseDir.

calibrationVideo [String or Array | []]

Calibration video (played from start at each calibration position). Supply either a calibration video or calibration image, not both.

This can be either an array of {src: ‘url’, type: ‘MIMEtype’} objects or just a string like attentiongrabber to rely on the baseDir and videoTypes to generate full paths.

calibrationImage [String | '']

Image to use for calibration - will be placed at each location. Supply either a calibration video or calibration image, not both.

This can be either a full URL or just the filename (e.g. “star.png”) to use the full path based on baseDir (e.g. baseDir/img/star.png).

calibrationImageAnimation [String | 'spin']

Which animation to use for the calibration image. Options are ‘bounce’, ‘spin’, or ‘’ (empty to not animate).

Data collected

No data is recorded specifically by this frame type.

Events recorded

The events recorded specifically by this frame are:

startCalibration

Beginning of each calibration segment

location

[String] The location of calibration image/video, relative to child: ‘left’, ‘right’, or ‘center’

Updating from deprecated frames

Updating an exp-lookit-composite-video-trial (or the old exp-lookit-video) frame

Your exp-lookit-composite-video-trial frame may have included a calibration phase. If so (calibrationLength set to >0), then you can replace that phase with an exp-lookit-calibration frame.

Consider the following exp-lookit-composite-video-trial frame which includes calibration:

"sample-physics-trial-2": {
    "kind": "exp-lookit-composite-video-trial",
    "baseDir": "https://www.mit.edu/~kimscott/placeholderstimuli/",
    "audioTypes": [
        "ogg",
        "mp3"
    ],
    "videoTypes": [
        "webm",
        "mp4"
    ],

    "attnSources": "attentiongrabber",
    "announceLength": 2,
    "audioSources": "video_02",

    "calibrationLength": 3000,
    "calibrationAudioSources": "chimes",
    "calibrationVideoSources": "attentiongrabber"

    "introSources": "cropped_block",

    "sources": "example_pairing",
    "altSources": "example_pairing",
    "testCount": 2,
    "musicSources": "music_02",

    "pauseAudio": "pause",
    "unpauseAudio": "return_after_pause",

}

To create the corresponding exp-lookit-calibration frame, you will change the kind to exp-lookit-calibration, rename calibrationAudioSources and calibrationVideoSources, and remove the irrelevant fields, like this:

"sample-physics-calibration": {
    "kind": "exp-lookit-calibration", <-- change the "kind"
    "baseDir": "https://www.mit.edu/~kimscott/placeholderstimuli/", <-- leave this the same
    "audioTypes": [ <-- leave this the same
        "ogg",
        "mp3"
    ],
    "videoTypes": [ <-- leave this the same
        "webm",
        "mp4"
    ],

    "calibrationLength": 3000,  <-- leave this the same
    "calibrationAudio": "chimes",  <-- just rename from "calibrationAudioSources"
    "calibrationVideo": "attentiongrabber"  <-- just rename from "calibrationVideoSources"
}

If your old frame defined calibrationPositions, you can leave that the same too. Otherwise this will continue to use the default of ['center', 'left', 'right', 'center'].

The one difference is that you will not yet be able to pause the study during the calibration phase.

Updating an exp-lookit-preferential-looking frame

Your exp-lookit-preferential-looking frame may have included a calibration phase. If so (calibrationLength set to >0), then you can replace that phase with an exp-lookit-calibration frame.

Consider the following exp-lookit-preferential-looking frame which includes calibration:

"sample-trial": {
    "kind": "exp-lookit-preferential-looking",
    "baseDir": "https://s3.amazonaws.com/lookitcontents/labelsconcepts/",
    "audioTypes": [
        "ogg",
        "mp3"
    ],
    "videoTypes": [
        "webm",
        "mp4"
    ],

    "announcementVideo": "attentiongrabber",
    "announcementAudio": "video_02",
    "announcementLength": 2,

    "introVideo": "cropped_book",

    "calibrationLength": 0,
    "calibrationAudio": "chimes",
    "calibrationVideo": "attentiongrabber",

    "pauseAudio": "pause",
    "unpauseAudio": "return_after_pause",

    "testAudio": "400Hz_tones",
    "loopTestAudio": false,
    "leftImage": "stapler_test_02.jpg",
    "rightImage": "novel_02.jpg",
    "testLength": 8,
}

You can change it to an exp-lookit-calibration frame just by changing the kind and removing the irrelevant parameters:

"sample-trial": {
    "kind": "exp-lookit-calibration", <-- change the "kind"
    "baseDir": "https://s3.amazonaws.com/lookitcontents/labelsconcepts/", <-- leave this the same
    "audioTypes": [ <-- leave this the same
        "ogg",
        "mp3"
    ],
    "videoTypes": [ <-- leave this the same
        "webm",
        "mp4"
    ],

    "calibrationLength": 0, <-- leave this the same
    "calibrationAudio": "chimes", <-- leave this the same
    "calibrationVideo": "attentiongrabber" <-- leave this the same
}

The one difference is that you will not yet be able to pause the study during the calibration phase.