Consciousness – Awareness of internal and external stimuli ◦ “personal awareness” ◦ Example.

Consciousness – Awareness of internal and external stimuli◦ “personal awareness”

◦ Example

Consciousness is not all or none

We still have some level of awareness during sleep and even while under anesthesia during surgery

Examples

Electroencephalograph (EEG) –a device that monitors electrical activity of the brain over time◦ Records electrodes attached to surface of scalp

This shows the rhythm of activity of brain (brain waves)

Circadian Rhythm – 24 hour biological cycles found in humans and other species◦ Influential in sleep regulation

These rhythms prime us to fall asleep easily at a certain point in day◦ “ideal” time

What happens when we ignore our biological clocks and sleep at an unusual time?◦ Quality suffers◦ Tired, sluggish, irritable for days, lower cognitive

performance

Equates with “jet lag”

This is especially problematic for workers constantly switching and working odd shifts.◦ What some studies show

Researchers have studied methods to get over this feeling of “jet lag”

Options◦ Certain type of drug (melanonin)◦ Carefully timed exposure to bright light◦ Carefully plan rotation schedules at work

Problem with options

Former thoughts about sleep…

Now realize that much physical and mental activity happens during sleep

How did we form this understanding?◦ Sleep Laboratories

Volunteer patients spend night What happens in these labs?

Video clip

Sleep onset is gradual

Once we fall asleep, humans progress through different stages

Stages 1-4- Commonly referred to as non-REM sleep◦ Respiration, heart rate, and body temperature

decrease with each stage◦ Brain waves increase as we progress

This is the fifth and final sleep stage

REM= Rapid eye movements◦ How are these measured?◦ How were they discovered?

REM is the deepest form of sleep◦ Rapid eye movements◦ High frequency brain waves◦ Dreaming

Sleep cycle (Stages 1-5) repeat during night

Cultures mostly similar in terms of sleep experience and activity◦ Differ on other matters

Co-sleeping- children and parents sleeping together◦ More accepted in other cultures

Examples

Napping◦ Some societies close shops and activities during day

to permit naps for an hour or two examples

Research has focused on sleep restriction – partial sleep deprivation

Seems that much of the U.S. are chronic sufferers◦ Effects our attention, reaction time, decision making

Night time workers fall asleep on job Numerous accidents are result of sleep

deprivation◦ Examples

Selective Deprivation ◦ Many lab studies awake participants whenever they

begin to go into REM◦ Selectively deprived of REM

As nights go by, need to awaken more and more◦ REM begins to happen more spontaneously in these

patients now

Following deprivation: Rebound Effect- patients spend extra time in REM

sleep for one to three nights

Insomnia- chronic problems getting adequate sleep◦ 15-17% of adults suffer from severe insomnia

Narcolepsy- marked by sudden, irresistible onsets of sleep during normal waking periods.◦ Awake directly to REM sleep◦ Very rare

Sleep Apnea- frequent, reflexive gasping for air that awakens person and disrupts sleep◦ Person literally stops breathing for 10 seconds

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