In my last blog we discussed at length the different stages of sleep, namely non-REM and REM, the biological need for sleep to stay alive, and started discussing what some researchers believe may be the function of some portions of non-REM sleep.  We reviewed how there is some evidence linking declarative memory (memory of facts and figures) to slow wave sleep and procedural memory (the ability to perform tasks like riding a bike or playing a musical instrument) to stage 2 sleep.  Now for the...