What are the states of consciousness?
Although we think of our mind as awake and asleep, there are actually three states of consciousness: Wakefulness, NREM (non-rapid eye movement) and REM (rapid eye movement) Sleep (Please see learn about your sleep). The three types of sleep are very different from each other. Table 1 summarizes the differences.
Table 1. Characteristics of the 3 Brain States
| Wakefulness | NREM Sleep | REM Sleep | |
|---|---|---|---|
Eye Movements | Present | Slow | Rapid |
Alertness | Alert and aware of
environment | Not alert or aware of environment | |
Brain activity | Active | Not active | Active |
Dreams | None | None | Present |
Motor Activity | Able to move | Muscles relaxed,
no movement | Muscles are paralyzed
(twitches can be seen) |
BP, HR,
Respiration,
Body Temperature
Regulation | Changes based
on activity | Body is at rest and
all are reduced. | Variability is present.
Body is poikilothermic* |
Summary | You are awake, able to
move and respond to
environment. “Active
mind in an active body.” | You are asleep; brain
and body are quiet and
resting. “Quiet mind in
a quiet body.” | You are asleep; brain is
active and muscles are
paralyzed. “Active mind
in a paralyzed body.” |
*absence of body temperature regulation
