Hi Yoon,
Your experiment code looks OK to me.
I did find it a little confusing that you’re using a variable named reward_duration to specify a volume in milliliters to dispense via the syringe pump (and, in the actions attached to variable reward, waiting for that numeric amount of time). But I see that the value of reward_duration is 0.15us (aka just 0.15), so if the intent is to dispense 0.15 mL as the reward, I believe everything should work correctly (and you’re not likely to care about the 15 microsecond wait when you assign to reward).
As to whether you want the image set repetitions to be independent (as they are now) or interleaved (like Chong did), that’s entirely up to you. Switching to the interleaved approach would require only minor changes to your experiment code, as detailed in this discussion. I can help you make that change, if you want to go that way.
Cheers,
Chris