A sinusoidal grating with a Gaussian envelope in a rectangular display area. Default is a grayscale grating that oscillates between pure black and white in a square area. Uses standard formulas for grating and envelope—see gabor_open.m if you want to check them.
If an element can end on its own, you don't need to set end conditions for it in property end (unless you want it to maybe end earlier).
No—runs until a condition you set in property end.
You can vary or allow the subject to adjust the following input properties of an object of this type in real time when it's running. If you need to make other properties adjustable, you can edit the element type code—see Element Type Programming Manual.
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).
Default: 2 cycles/deg
Spatial frequency (cycles/deg).
An angle clockwise (deg) setting orientation of the grating. 0 = vertical bars. Note this sets orientation of the grating within the display area—to rotate the whole display, you can use property rotation.
Phase (cycles). 0 = sine grating centered in the element display area, 0.5 = negative sine grating, 0.25 = cosine grating, etc.
Defaults: meanIntensity = 0.5, amplitude = 0.5
meanIntensity is a number between 0–1 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 is max intensity − mean intensity.
contrast is Michelson contrast, amplitude / mean intensity. If you set contrast, mean intensity must be > 0.
It's possible to set a combination of these properties that causes the grating to clip at intensity 0 or 1. See record properties maxAmplitude and maxContrast below.
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 perpendicular to the orientation of the grating and y is parallel to it (so x = horizontal and y = vertical for a vertical grating). Grating orientation is set using orientation above.
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 all other intensities is linearly interpolated between the two.
PsychBench uses record properties to record information during experiments. You can't set record properties but you can see them in experiment results by listing them input property report.
Maximum amplitude and contrast where intensity would clip at 0 or 1, whichever is reached first, given the set mean intensity.