Moving Dots¶
Description¶
A moving dot field stimulus
Signature¶
stimulus/moving_dots
Required Parameters¶
field_radius¶
Field radius (degrees)
field_center_x¶
Field horizontal center position (degrees)
field_center_y¶
Field vertical center position (degrees)
dot_density¶
Number of dots per square degree
dot_size¶
Dot diameter (degrees)
direction¶
Direction of movement for coherent dots (degrees)
speed¶
Dot speed (degrees per second)
Optional Parameters¶
color¶
| Default: | 1.0,1.0,1.0 |
|---|
Dot color, expressed as a comma-separated list of red, green, and blue components with values between 0 and 1 (inclusive). The list can include variable names in place of explicit values, in which case the corresponding component value will be read from the named variable.
alpha_multiplier¶
| Default: | 1.0 |
|---|
Controls the transparency of the dots. 1.0 is fully opaque, while 0.0 is fully tranparent.
coherence¶
| Default: | 1.0 |
|---|
Fraction of dots that move in the specified direction. Non-coherent dots receive random directions.
lifetime¶
| Default: | 0.0 |
|---|
Dot lifetime (seconds). When a dot reaches the end of its lifetime, it is removed and replaced by a new dot in a random location.
announce_dots¶
| Default: | NO |
|---|
If YES, stimulus announcements (i.e. #announceStimulus and
#stimDisplayUpdate events) will include dot positions.
Position data is encoded as a binary array of single-precision floating point values (in platform byte order), with each consecutive pair of values representing the (x,y) coordinates of a dot. The coordinates are scaled to lie in the range [-1,1] and rotated so that the direction of coherent motion is zero degrees.
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.
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.