White Noise Background¶

Description¶

White noise background stimulus.

Fills the display with random noise drawn from a uniform distribution. The experiment can re-randomize the noise via the Randomize White Noise Background action.

Signature¶

stimulus/white_noise_background

Optional Parameters¶

grayscale¶

Default:: YES

If YES, all three color channels (red, green, and blue) of a given noise grain will be assigned the same random value. If NO, each color channel will be set to an independent random value, thereby producing colored noise.

grain_size¶

Default:: 0.0

Noise grain size (degrees).

The number of grains in each dimension is rounded to the nearest integer. Grain sizes less than or equal to the size of one pixel will result in per-pixel randomization.

rand_seed¶

Seed value for the random number generator. If omitted, the current system time in nanoseconds is used.

randomize_on_draw¶

Default:: NO

If YES, the stimulus will re-randomize itself every time it draws. Drawing may be triggered either explicitly (via an Update Stimulus Display action) or implicitly (e.g. at the request of a running dynamic stimulus).

To generate dynamic white noise that updates on every display refresh, use this parameter in conjuction with a Frame List Stimulus:

frame_list dynamic_noise (
    loop = true
    autoplay = true
    ) {
    white_noise_background (
        randomize_on_draw = true
        )
}

deferred¶

Options:: no

yes

explicit
Default:: no

Controls when the stimulus is loaded. If no, the stimulus is loaded at experiment load time. If yes, the stimulus is loaded the first time it is queued. If explicit, the stimulus must be loaded explictly with Load Stimulus.

display¶

Name of the display on which the stimulus will be presented. If omitted, the default display (if available) will be used.

Placement¶

Allowed at top level:	Yes
Allowed parent:	Compound Stimulus, Folder, Frame List Stimulus, Layer Stimulus, List Replicator, Movie Stimulus, Range Replicator, Stimulus Group