A sinusoidal grating in a Gaussian envelope. Includes options for flicker and phase drift. See also element type grating.

No—runs until a condition you set in property end.

size

Default: square with sides 5 deg

Sets display area for the Gabor. A number that is side length for a square, or a vector [width height] for a rectangle (deg).

frequency

Default: 2 cycles/deg

Spatial frequency (cycles/deg).

orientation

Default: sine grating left → right (vertical bars)

Orientation angle of the grating, + = clockwise (deg). 0 = sine grating left → right (vertical bars). This sets rotation of the grating within its rectangular display area. For rotation of the whole display use property rotation.

phase

Default: sine grating with angle = 0 at center

Phase of grating (cycles). 0 = sine grating with angle = 0 at display center, 0.5 = negative sine grating, 0.25 = cosine grating, etc. Display center is at element position.

meanIntensity
amplitude
contrast

Defaults: meanIntensity = 0.5, amplitude = 0.5

meanIntensity is a number between 0–1 (black–maximum) setting the intensity the grating oscillates about, also the intensity it decays toward at its edges due to the Gaussian envelope.

Also set one of amplitude OR contrast:

amplitude is max intensity − mean intensity.

contrast is Michelson contrast, amplitude / mean intensity. If you set contrast, mean intensity must be > 0.

Intensity always clips at 0 and 1. It's possible to set a combination of these properties that causes the grating to clip in this way. See record properties maxAmplitude and maxContrast below.

sigma

Default: 0.75 deg

Standard deviation for a symmetric Gaussian envelope (deg). <cd>inf<cd> = no envelope.

You can also use a vector <cd>[s_x s_y]<cd> for an asymmetric envelope. Here x is in the direction of the grating (perpendicular to its bars). Grating orientation can be set using orientation above.

color

Default: white <cd>[1 1 1]<cd>

A 1×3 RGB vector with numbers between 0–1. This defines the color at intensity = 1. Color at intensity = 0 is <cd>[0 0 0]<cd>. Color at intensities between 0–1 is linearly interpolated between the two. Note intensity, as defined by amplitude/contrast + meanIntensity above, always clips at 0 and 1, so color clips at <cd>[0 0 0]<cd> and color.

flickerFrequency
temporalFrequency

Defaults: no flicker or phase drift

You can set one of flickerFrequency OR temporalFrequency:

flickerFrequency is frequency of switching between dark–light (cycles/sec). 0 = no flicker.

temporalFrequency is continuous phase drift rate. This can be positive or negative to specify direction (+ = direction of orientation above, − = opposite direction, cycles/sec). 0 = no phase drift.

position
nn_eyes
rotation
colorMask
alpha
intensity
contrastMult
drawCodeVars

maxAmplitude
maxContrast

Values for input properties amplitude and contrast that would cause intensity to clip at 0 or 1 given the current value of meanIntensity.