Quick ReviewQuick Review• What is consciousness? Define preconscious, What is consciousness? Define preconscious,

nonconscious, and unconscious, and subconcious. nonconscious, and unconscious, and subconcious.

• What is your biological clock and circadian What is your biological clock and circadian rhythm?rhythm?

11/09/1011/09/10

• Objective – Learn the Stages of Objective – Learn the Stages of Sleep, and map a night of sleep Sleep, and map a night of sleep

The Stages of SleepThe Stages of Sleep

Please don’t fall asleep Please don’t fall asleep during the power during the power

point!!point!!

SleepSleep• Sleep is a Sleep is a ‘state’ of consciousness‘state’ of consciousness that we that we

have no knowledge of being in until we have no knowledge of being in until we wake up.wake up.

• Sleep is defined by Sleep is defined by slowed breathingslowed breathing and and irregular brain waves.irregular brain waves.

• Stages one through four are referred to as Stages one through four are referred to as non-rapid eye movement (NREM).non-rapid eye movement (NREM).

Light Sleep - Stage 1Light Sleep - Stage 1

•Body movement decreasesBody movement decreases

•Spontaneous Waking may Spontaneous Waking may occur (when you feel like occur (when you feel like you are falling out of bed)you are falling out of bed)

Intermediate Sleep - Stage 2Intermediate Sleep - Stage 2

• Officially asleepOfficially asleep

• Your brain waves slow down with Your brain waves slow down with some bursts of brain activity called some bursts of brain activity called ‘Sleep Spindles’ ‘Sleep Spindles’

• half of your sleep in this stage. half of your sleep in this stage.

• Helps refresh bodyHelps refresh bodySleep Talking can occur during this and all future sleep stages.Sleep Talking can occur during this and all future sleep stages.

Deep Sleep – Stage 3 -4Deep Sleep – Stage 3 -4

• Deep sleep sets in – hard to wake upDeep sleep sets in – hard to wake up

• brain waves become large and slowbrain waves become large and slow

• Your breathing becomes rhythmic, Your breathing becomes rhythmic, and your muscles remain relaxed. and your muscles remain relaxed.

• Most Restorative stage (reparative Most Restorative stage (reparative hormones released)hormones released)

• 30-40 min first and shorter later30-40 min first and shorter later

Deep Sleep – Stage 3 -4Deep Sleep – Stage 3 -4

• Towards the end of stage 4, children may Towards the end of stage 4, children may wet beds, adults may sleep walk, etc…wet beds, adults may sleep walk, etc…

• Interestingly,Interestingly, even though you are in even though you are in deep sleep, your brain will still process deep sleep, your brain will still process the meaning of certain stimuli!!the meaning of certain stimuli!!

REM Sleep - REM Sleep - Rapid Eye MovementRapid Eye Movement

• Nearly an hour after you fall asleep, you begin Nearly an hour after you fall asleep, you begin to descend back through the stages of sleep. to descend back through the stages of sleep.

• During sleep you go stages 1,2,3,4,3,2 then…During sleep you go stages 1,2,3,4,3,2 then…

• You then enter what is known as REM Sleep!You then enter what is known as REM Sleep!

REM –This stage only lasts about 10 minutes. REM –This stage only lasts about 10 minutes. (20 – 30 minutes later in night)(20 – 30 minutes later in night)

REM Sleep - REM Sleep - Rapid Eye MovementRapid Eye Movement

• heart rate risesheart rate rises• breathing becomes rapidbreathing becomes rapid• every 30 seconds or so, your eyes rapidly every 30 seconds or so, your eyes rapidly

move around.move around.

• motor cortex is still active, but your brainstem motor cortex is still active, but your brainstem blocks any messages. blocks any messages.

• This leaves your muscles so relaxed that you are This leaves your muscles so relaxed that you are essentially paralyzed.essentially paralyzed.

Thus, you are not easily awakened.Thus, you are not easily awakened.

The cycle repeats itself every 90 The cycle repeats itself every 90 minutes or so.minutes or so.

As the night progresses, we As the night progresses, we spend less and less time in stage spend less and less time in stage

4 and more in REM.4 and more in REM.

By the time we wake-up, we By the time we wake-up, we have spent 20 – 25% of the have spent 20 – 25% of the

night in REM Sleep.night in REM Sleep.

Pretend you could map last Pretend you could map last night’s sleeping pattern. night’s sleeping pattern.

• Now draw a map of a night of sleep. Now draw a map of a night of sleep. What time do you fall asleep? When What time do you fall asleep? When do you wake up? How many times do you wake up? How many times could you have dreamt? Did you could you have dreamt? Did you wake up at all?wake up at all?