Flowerpot technique

The Flowerpot technique is used in sleep deprivation studies. It is designed to allow NREM sleep but prevent REM sleep. A laboratory rat is placed on top of an upside down flowerpot which is placed in a bucket of water. While in NREM sleep the rat retains muscle tone so it can sleep on top of the flowerpot. When the rat enters REM sleep it will lose muscle tone and fall off the flowerpot into the water, then climb back up and re-enter NREM sleep.