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).
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).
alpha_multiplier¶
| Default: | 1.0 |
|---|
Controls the transparency of the stimulus. 1.0 is fully opaque, while 0.0 is fully tranparent.
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.
Placement¶
| Allowed at top level: | Yes |
|---|---|
| Allowed parent: | Folder, List Replicator, Range Replicator, Stimulus Group |