stop attribute

The stop command specifies the conditions in which a trial should end.

Member of

Syntax

/ stop = [expression; expression; expression; ...]

Parameters

expression

Specifies the expression to evaluate to determine whether the trial should stop.

Remarks

When the stop command is defined for a trial, the trial continues to run and poll for responses until the logical expression is the stop condition is true. The stop command is useful for tracking multiple responses within a trial or tracking continuous response data. For example, a test that measures Visual Analog Scale responses as participants watch a video would check that the video is no longer playing as a stop condition. Every valid response made before the trial stops is registered and triggers any associated response, error, or correct messages.

Examples

The following trial plays a video until the end, registering left and right mouse button clicks along the way:

<trial vsa>
/ stimulusframes=[1=testvideos]
/ stop=[video.testvideos.isplaying == false;]
/ validresponse=(lbuttondown, rbuttondown)
</trial>