Stimulus Display

Description

A stimulus display device.

At present, MWorks creates one (and only one) of these automatically when needed, 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.

Note: Start IO Device, Stop IO Device, and autostart have no effect on this device.

Signature

iodevice/stimulus_display

Required Parameters

background_color

Example

0.5,0.5,0.5

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

background_alpha_multiplier

Default

1.0

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.

redraw_on_every_refresh

Default

NO

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.

announce_stimuli_on_implicit_updates

Default

YES

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, #stimDisplayUpdate events for implicit updates will contain only the number of stimuli displayed (in place of the usual list of stimulus parameters).

autostart

Default

NO

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.

alt

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.

Placement

Allowed at top level:

Yes

Allowed parent:

Folder