In long experiments, it is often desirable to give the participant a break after a number of trials has been presented. Separating trials into two different blocks works but only when not randomizing. If you need to randomize the trials as a single set, they must remain in one block.
Providing the break can simply be done using the conditional branching feature. Here is step by step example; we will start by creating the event that displays a message to the participant. The example assumes that you already have an experiment setup and you only need to add the break.
In the main experiment window, click on the list of events; the selection rectangle will move from the list of trials to the list of events
In the toolbar, click on the New Event icon; the Event Editor will appear
For the event name, type “Participant Break”
Click on the Stimulus tab to select it if it’s not selected already
Click on the Event Type popup menu and select Text
In the large text editing field, type:
You can now take a break.
When you are ready to continue,
press any key to continue.
Click on the OK button. The Event Editor will go away and “Participant Break” will appear in the list of events.
The next step is to create a macro:
In the main experiment window, double-click on your block to edit it
Click on the Macros tab
Click on the New button icon to create a new macro; the Macro Editor appears
In the Expression tab, click on the New (+) button; the Expression Editor appears
In the list of variables on the left, click on Trials Presented in This Block; three "functions" appear automatically on the right side
Click on the Number of function to select it if it's not selected already
In the RHS (right hand side) section at the bottom
of the dialog, enter the number of trials after which you want to introduce
a pause, e.g. type 30 if you want to give the participant a break after
30 trials
Click on the OK button to close the Expression Editor (but not the Macro Editor). Only a few steps remain:
While still in the Macro Editor, click on the If true tab
Click on the New button icon to create a new action; the New Action dialog appears
Click on the "Do the Following" popup menu and select "Present Event"
Click on the "Select Event" popup menu and select the "Participant Break" event that you created earlier
Click on OK to close the New Action dialog
Click on OK to close the Macro Editor dialog
You should now be back in the Block Editor. You
created a macro but you still need to tell SuperLab to use it:
Click on the blue checkbox to the left of the macro to select it
Click on the OK button to close the Block Editor
That's it; the participant should now get the "Participant Break" event presented after 30 trials. You can re-use a macro in any number of blocks.