Fixation Point Stimulus¶
Description¶
A rectangular fixation point stimulus. Also serves as a “calibratable” object for calibrator-related actions (e.g. Take Calibration Sample, End Averaged Calibration Sample).
Signature¶
stimulus/fixation_point
Required Parameters¶
trigger_width¶
Width of the (square) fixation window, which shares its center with the visible stimulus rectangle
trigger_watch_x¶
Variable containing the horizontal eye position
trigger_watch_y¶
Variable containing the vertical eye position
trigger_flag¶
Variable to which fixation status is written. When the subject’s gaze (as reported by trigger_watch_x and trigger_watch_y) enters the fixation window, the variable is set to true. When the subject’s gaze leaves the fixation window, the variable is set to false.
Optional Parameters¶
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
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.
Placement¶
Allowed at top level: |
Yes |
---|---|
Allowed parent: |
Folder, Frame List Stimulus, Layer Stimulus, List Replicator, Movie Stimulus, Range Replicator, Stimulus Group |