Have you ever wondered as to how do you actually fall asleep? What really happens when you doze off? We fall asleep everyday but, yet, we do not know of the exact mechanisms behind. We just switch from a state of wakefulness to sleep where we are in some kind of comatose condition. What are the processes that occur at the level of the brain that allows for this?
Research suggests that the transition from the two states is more of a gradual process than a sudden one. the new study focused on the pre-sleep stage that comes before one falls completely asleep. During this period, the brain waves display “alpha activity” which has been linked with quiet wakefulness – the period when you’re slowly being pulled into the sleep-world.
“It is in this period that the brain progressively disengages from the external world,” Linda Larson-Prior and her colleagues wrote in a 2011 paper. “Subjects slowly oscillate between attending to external and internal thoughts, with the majority of internal thoughts being autobiographical or self-referential in nature.”
After this instance, stage one starts: the transitional sleep stage. Brain waves decelerate and get into “theta-band activity”, with occasional signs of “alpha activity”. When this happens, one still has the sense of wakefulness, as though one is still awake.
“Investigators asked subjects aroused out of various stages of sleep whether they considered themselves asleep. Only about 10 percent of those aroused from stage 1 said that they had been asleep.”
The 2nd stage entails REM (rapid eye movement) sleep whereby all alpha activity dies out. Scientists have tagged this phase as actual sleep.
Stage 3 & 4
Stages 3 and 4 quickly follow: slow wave sleep. This leads to REM sleep, the phase where dreams are said to occur. It is only after these stages that most people have definitely fallen asleep.
We go through a number of phases marked by differences in brain activity before we are actually turned off and take off to dream-land. These results show that only gradually do we fall completely asleep.