A moving dot field stimulus
Field radius (degrees)
Number of dots per square degree
Dot diameter (degrees)
Dot speed (degrees per second)
Field horizontal center position (degrees)
Field vertical center position (degrees)
Dot color, 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).
Controls the transparency of the dots.
1.0 is fully opaque, while
0.0 is fully tranparent.
Direction of movement for coherent dots (degrees)
Fraction of dots that move in the specified direction. Non-coherent dots receive random directions.
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.
YES, stimulus announcements (i.e.
#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.
Seed value for the random number generator. If omitted, the current system time in nanoseconds is used.
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.
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.