The spatial n-back is a single n-back task based on spatial locations as the stimuli stream. N-Back tasks involve presenting a stream of stimuli to a participant which they must monitor and respond when they believe the current stimulus is the same as the stimulus presented 'n' items ago. Therefore in this spatial n-back task the stimuli are made up of the 9 locations on screen represented by the red squares. The stimuli stream is presented by changing the red circles to green one at a time.

You can download the default XML here. In this section I will point out the customisation options at your disposal by modifying values in the XML.