Why dreams like flying, falling, being chased are so common, and how your brain creates them

The air rushes past my face, whipping my hair into my eyes as I plunge into the dark. Rapid eye movement or REM sleep is often called "paradoxical sleep", Professor Schoenhammer said. REM and non-REM sleep cycle The first three stages of sleep are non-REM Brain waves, heart rate, blood pressure and breathing become slower as you sink into deeper non-REM sleep This all changes when you enter REM sleep, typically around 90 minutes after falling asleep In REM sleep, brain wave activity increases to near waking levels, as do heart rate and blood pressure, and breathing becomes faster and irregular You cycle through non-REM and REM sleep several times during the night, with increasingly longer, deeper REM periods towards the morning Source: US National Institute of Neurological Disorders and Stroke "Parts of your brain are more alert than when you're awake, but at the same time, you are paralysed from the neck down — only your eyes move." Why typical dreams are often bad dreams Whether a typical dream is pleasant or not could depend on your state of mind at the time, Professor Schoenhammer said. "So this might be why more typical dreams tend to be not so nice," Professor Schoenhammer said.