Millisecond Forums

Hi Inquisit Community,
I wonder whether the valid response can be specified when presenting two overlapped stimuli.
I wish the valid response is specified as only the blue part but including not the overlapping part.
for example I was looking for something like
/ stimulustimes = [0=Layer1,Layer2]
/ validresponse = (Layer1 & -Layer2) 
Is there a way to do this?
Thank you in advance.