Stimulus Display


A stimulus display device. At present, MWorks always creates one (and only one) of these per experiment, regardless of whether the experiment file defines one. By including a definition in your experiment file, you can change the display’s default background color and configure its run-time behavior.



Required Parameters



The background 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).

Optional Parameters



Controls the transparency of the background. 1.0 is fully opaque, while 0.0 is fully tranparent.

Note: To enable background transparency, you must set #mainScreenInfo’s make_window_opaque key to false. To make the stimulus display window fully transparent, set this parameter and all components of background_color to 0.



If YES, the display will be redrawn during every refresh cycle. If NO, the display will be redrawn only when needed or when explicitly requested via Update Stimulus Display.



Controls the announcement of stimuli during “implicit” display updates (i.e. updates requested by running dynamic stimuli and not triggered by an explicit Update Stimulus Display action). If set to NO, then implicit updates will not generate #announceStimulus events, and #stimDisplayUpdate events for implicit updates will contain only the number of stimuli displayed (in place of the usual list of stimulus parameters).



If YES, the device will start I/O automatically (as if by an implicit Start IO Device action) when the experiment starts running.

Note: Device I/O will always stop automatically when the experiment stops running, irrespective of this setting.


Alternative device to use if this one fails to initialize (e.g. because the required hardware is not available). If #allowAltFailover is set to 0 or false, this parameter is ignored.


Allowed at top level: Yes
Allowed parent: Folder