Drifting Grating Stimulus¶
Description¶
A drifting grating stimulus
Signature¶
stimulus/drifting_grating
Required Parameters¶
Optional Parameters¶
compute_phase_incrementally¶
- Default
NO
If NO, the current phase of the grating is computed from
starting_phase, spatial_frequency, speed, and the total time
elapsed since the stimulus started playing.
If YES, the current phase is computed from the previous phase (i.e.
the phase when the stimulus was last drawn), spatial_frequency,
speed, and the time elapsed since the previous phase was computed.
This parameter is relevant only when the stimulus is live queued and the values of starting_phase,
spatial_frequency, and/or speed are changed while the stimulus is
playing. Most notably, if the parameter’s value is NO, then changes
to speed will cause a discontinuous jump in phase. If the value is
YES, then changes to speed will be smooth, with no phase jump.
mask¶
- Default
NO
If YES, the grating will function as a mask (similar to a Mask Stimulus). When used as part of a layer, “high”
regions of the grating (where the value is close to one) will allow
stimuli beneath it in the layer to show through, while “low” regions
(where the value is near zero) will partially or fully erase such
stimuli, exposing any stimuli beneath the layer.
When the value of this parameter is YES, color and
alpha_multiplier are ignored.
Note: For compatibility with existing experiments, the value of this
parameter can also be one of rectangle, ellipse, or
gaussian, in which case it specifies the type of mask to apply to
the grating. However, this usage is deprecated, and new experiments
should use a Mask Stimulus instead.
inverted¶
- Default
NO
If YES, all grating values are inverted, e.g. high values become low, and low values become high
color¶
- Default
1.0,1.0,1.0
The color of the stimulus, expressed as a comma-separated list of red, green, and blue components. Each component may be described by any valid expression, but the expression must result in a value between 0 and 1 (inclusive).
alpha_multiplier¶
- Default
1.0
Controls the transparency of the stimulus. 1.0 is fully opaque, while 0.0 is fully tranparent.
x_size¶
- Example
5.0
Horizontal size (degrees).
If omitted, the value of y_size is used. It is an error to omit both
x_size and y_size (unless fullscreen is YES).
y_size¶
- Example
5.0
Vertical size (degrees).
If omitted, the value of x_size is used. It is an error to omit both
x_size and y_size (unless fullscreen is YES).
fullscreen¶
- Default
NO
If YES, the stimulus is sized to fill the display. In this mode, x_size, y_size, x_position, y_position, and rotation are ignored.
deferred¶
- Options
noyesexplicit- 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.
autoplay¶
- Default
NO
If YES, the stimulus will start playing automatically (as if by an implicit Play Dynamic Stimulus action) after it has been queued and Update Stimulus Display has been invoked. It will also stop playing automatically (as if by an implicit Stop Dynamic Stimulus action) after it has been dequeued and Update Stimulus Display is invoked.
Deprecated Parameters¶
mean¶
- Default
0.0
Mean of Gaussian mask.
This value determines the radial offset of the Gaussian peak from the center of the grating. If non-zero, the peak will be a circle, rather than a point, and luminance will decrease both inside and outside the circle, producing a toroidal stimulus.
normalized¶
- Default
YES
If YES, the Gaussian mask includes a multiplicative normalization term (1/(std_dev*sqrt(2*pi))). If NO, this term is omitted.
Placement¶
Allowed at top level: |
Yes |
|---|---|
Allowed parent: |
Folder, Frame List Stimulus, Layer Stimulus, List Replicator, Movie Stimulus, Range Replicator, Stimulus Group |