Quick Review What is consciousness? Define preconscious, nonconscious, and unconscious, and subconcious. What is consciousness? Define preconscious, nonconscious, and unconscious, and subconcious. What is your biological clock and circadian rhythm? What is your biological clock and circadian rhythm?

11/09/10 Objective – Learn the Stages of Sleep, and map a night of sleep Objective – Learn the Stages of Sleep, and map a night of sleep

The Stages of Sleep Please don’t fall asleep during the power point!!

Sleep Sleep is a ‘state’ of consciousness that we have no knowledge of being in until we wake up. Sleep is a ‘state’ of consciousness that we have no knowledge of being in until we wake up. Sleep is defined by slowed breathing and irregular brain waves. Sleep is defined by slowed breathing and irregular brain waves. Stages one through four are referred to as non- rapid eye movement (NREM). Stages one through four are referred to as non- rapid eye movement (NREM).

Light Sleep - Stage 1 Body movement decreases Body movement decreases Spontaneous Waking may occur (when you feel like you are falling out of bed) Spontaneous Waking may occur (when you feel like you are falling out of bed)

Intermediate Sleep - Stage 2 Officially asleep Officially asleep Your brain waves slow down with some bursts of brain activity called ‘Sleep Spindles’ Your brain waves slow down with some bursts of brain activity called ‘Sleep Spindles’ half of your sleep in this stage. half of your sleep in this stage. Helps refresh body Helps refresh body Sleep Talking can occur during this and all future sleep stages.

Deep Sleep – Stage 3 -4 Deep sleep sets in – hard to wake up Deep sleep sets in – hard to wake up brain waves become large and slow brain waves become large and slow Your breathing becomes rhythmic, and your muscles remain relaxed. Your breathing becomes rhythmic, and your muscles remain relaxed. Most Restorative stage (reparative hormones released) Most Restorative stage (reparative hormones released) min first and shorter later min first and shorter later

Deep Sleep – Stage 3 -4 Towards the end of stage 4, children may wet beds, adults may sleep walk, etc… Towards the end of stage 4, children may wet beds, adults may sleep walk, etc… Interestingly, even though you are in deep sleep, your brain will still process the meaning of certain stimuli!! Interestingly, even though you are in deep sleep, your brain will still process the meaning of certain stimuli!!

REM Sleep - Rapid Eye Movement Nearly an hour after you fall asleep, you begin to descend back through the stages of sleep. Nearly an hour after you fall asleep, you begin 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. (20 – 30 minutes later in night)

REM Sleep - Rapid Eye Movement heart rate rises heart rate rises breathing becomes rapid breathing becomes rapid every 30 seconds or so, your eyes rapidly move around. every 30 seconds or so, your eyes rapidly move around. motor cortex is still active, but your brainstem blocks any messages. motor cortex is still active, but your brainstem blocks any messages. This leaves your muscles so relaxed that you are essentially paralyzed. This leaves your muscles so relaxed that you are essentially paralyzed. Thus, you are not easily awakened.

The cycle repeats itself every 90 minutes or so. As the night progresses, we spend less and less time in stage 4 and more in REM. By the time we wake-up, we have spent 20 – 25% of the night in REM Sleep.

Pretend you could map last night’s sleeping pattern. Now draw a map of a night of sleep. What time do you fall asleep? When do you wake up? How many times could you have dreamt? Did you wake up at all? Now draw a map of a night of sleep. What time do you fall asleep? When do you wake up? How many times could you have dreamt? Did you wake up at all?