bgStim attribute

The bgStim attribute specifies a set of background stimuli to present at the beginning of a block of trials.

Member of

Syntax

/ bgStim = (stimulusname, stimulusname, stimulusname)

Parameters

Name	Type	Description
stimulusname	stimulus	The name of a stimulus element defined elsewhere in the script.

Remarks

This attribute is useful for presenting ambient background stimuli that hang around on the screen throughout a block of trials. Common uses include brief instructions to remind the subject how to respond (e.g., "Press the "a" for pleasant or "b" for unpleasant" or "Respond as quickly and accurately as you can"). The background stimuli are not erased until the block is finished, although they can be overwritten by other stimuli presented during the trials.

Examples

The following block presents two background stimuli:

<block myBlock>
/ trials=[1-10=noReplace(trial1, trial2)]
/ bgStim=(reminderText, instructionText)
</block>