This sample experiment demonstrates two methods for implementing an inter-trial interval.
The first block of this experiment uses a nested List object to select a random inter-trial interval from a set of specific values (i.e., 500, 1000, 1500, or 2000). The ITIDur attribute will select a value from the ITIList randomly and independent of the trial selected by the NestedTrialList. The WaitITI object has its Duration property set to reference the ITIDur attribute.
The second block of this experiment uses a bit of InLine script to select a random inter-trial interval between a set of boundaries. The Random function used in the SelectITI InLine object will choose any integer value between the lower bound (500) and the upper bound (2000). The script then assigns the random value to the ITIDur attribute, which is again referenced in the WaitITI object’s Duration property.