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States of Consciousness
Transcript of States of Consciousness
Sleep and Rhythms
Consciousness is our awareness of ourselves and our environment.
There are several states of consciousness:
Why Do We Need Sleep?
Everyone knows that getting
is vital for our
energy and mood levels,
but what happens when we don't get enough sleep?
(hallucinations of the sleeping mind),
are vivid, emotional and bizarre.
They are often
that we may
them with reality.
is defined as a social interaction in which the
suggests to the
that certain perceptions, feelings, thoughts, or behaviors will
Although we may not think of
as a state of consciousness, it actually is what causes our bodies to roughly
synchronize with the 24 hour cycle of day and night.
It does this through the
" being Latin for "
," and "
" being Latin for "
circadian rhythm is our biological clock,
our regular bodily rhythms that occur on a 24 hour cycle.
in the morning tweaks the circadian clock by
activating light-sensitive retinal proteins
. These proteins
control the circadian clock by triggering signals to the brain's suprachiasmatic nucleus
(SCN) located in the brain's
causes the brain's
pineal gland to decrease its production
of the sleep-inducing hormone
increase it in the evening.
As we sleep, our brain goes through
(rapid eye movement sleep) is a
recurring sleep stage during which vivid dreams commonly occur.
muscles are relaxed
aside from minor twitches at this point, but
other body systems are active.
Measured with an
, we can see the
relatively slow alpha
waves of your
awake (but relaxed)
is marked by the
slow breathing and irregular brain waves of Stage 1.
During this brief
, you may experience fantastic images resembling
sensation of falling or of floating weightlessly
). You then
relax more deeply
and begin about
20 minutes of Stage 2
sleep (which is where
Then for the next few minutes you go through the
transitional Stage 3
(in which your brain begins to emit
large, slow delta waves
) to the
deep sleep of Stage 4.
stages last for about
, during which you would be
hard to awaken
(for example, sleeping through a thunder storm). It is at the
end of Stage 4
that children may
wet the bed or begin sleep walking.
REM sleep your heart rate rises, your breathing becomes rapid and irregular, and your eyes dart around
in a momentary burst of activity behind closed eyelids. Although your
brain's motor cortex is active during REM sleep, your brainstem blocks its messages
, leaving muscles so relaxed that you are
The sleep cycle
repeats itself around every 90 minutes
, but the
deep Stage 4 sleep gets progressively briefer
and then disappears while the
REM and Stage 2 sleep periods get longer.
of our average night's sleep (some 100 minutes) has been
Sleep deprivation lowers productivity, decreases memory, increases hunger, suppresses our immune system, and impairs daily functions.
We still don't know the exact reason why we need sleep, but
sleep may have evolved
for 5 reasons:
1.) Sleep Protects
a species' sleep pattern tends to suit its ecological niche
. Animals with the greatest need to graze and the least ability to hide tend to sleep less (giraffes sleep around 2 hours a day, elephants and horses sleep 3 to 4 hours a day, whereas gorillas and cats sleep between 12 and 14 hours a day.
2.) Sleep Helps Us Recuperate
it helps restore and repair brain tissue
, and allows unused connections to weaken.
Amygdala and sleep deprivation:
side of the brain is much
3.) Sleep Is For Making Memories - it helps restore and rebuild our fading memories
of the day's experiences.
4.) Sleep Feeds Creative Thinking
a complete night's sleep gives us a boost in insight and allows us to discern connections
among different novel pieces of information.
5.) Sleep May Play A Role In The Growth Process
during deep sleep, the pituitary gland releases a growth hormone
, and as we age we release less of this hormone and spend less time in deep sleep.
However, no matter what their normal need for sleep, around
of the population suffers from
insomnia (a recurring problem in falling or staying asleep)
(from narco, "numbness," and lepsy, "seizure")
sufferers experience periodic, overwhelming sleepiness
. Attacks usually last less than 5 minutes, but sometimes occur at the most inopportune times.
(apnea = "with no breath") is a sleep disorder characterized by
of breathing during sleep and repeated momentary awakenings.
It affects around
1 in 20
Americans, and leads to
sleepiness and irritability
during the day.
target mostly children during
of sleep, where they may
sit up, walk around, talk incoherently, have a doubling of heart and breathing rate, and appear terrified.
Stage 4 sleeping disorders
that are usually harmless and often run in families.
referred to the remembered story line of a dream (which incorporates traces of previous days' experiences and preoccupation) as its
in our sleeping environment
may also intrude
(for instance, the ringing of your cell phone may become
into your dream)
William Dement and Edward Wolpert would spray cold water on dreamers' faces.
Compared with sleepers who did not get this treatment were
to dream about water. This shows us that even in REM we maintain
of changes in our external environment.
Why Do We Dream?
There are several
as to why we dream:
To satisfy our own wishes.
Freud believed that
a dreams' manifest (literal) content is a censored, symbolic version of its latent content
(which consists of unconscious drives and wishes)
For example, Freud would view a dreamt image of a gun as a disguised representation of a penis.
To file away memories.
Researchers who see dreams as
dreams may help sift, sort, and fix the day's experiences in our memory.
It has been proven that
during the day will
the number and intensity of dreams during the night; this may imply that the
brain is dealing with daily stress and information during REM dreams.
This may also be why
babies need more REM
sleep than adults: they're processing
so much new information
To develop and preserve neural pathways
. Some researchers believe that
give our sleeping brains
, which helps keep our neuronal pathways healthy and happy.
To make sense of neural static
. Other theories propose that dreams erupt from
neural activity spreading upward from the brainstem.
According to one version,
neural activity is random
, and dreams are the brain's attempt to make sense of it. This
stimulation originating within the brain
brain areas that process
(NOT the visual cortex).
To reflect cognitive development
. Some researchers believe dreams have to do with the brain's
maturation and cognitive development.
They overlap with waking cognition, and feature coherent speech, as well as draw on our concepts and knowledge
Although psychologists cannot agree on a reason why we dream, they can agree on a phenomenon known as
; during which
the tendency for REM sleep increases after interrupted REM sleep
(also known as REM sleep deprivation)
This occurs in
most other mammals
, which suggests that the causes and functions of REM sleep are
This MRI scans show
in women with alcohol dependence.
to a psychoactive drug,
the drug's effect lessens
. Thus it takes
to get the desired effect. This is known as
To an extent, everyone is susceptible to hypnosis.
is a form of
Hypnotherapists try to help patients harness their own healing powers through posthypnotic suggestions.
It's been shown to alleviate headaches, asthma, and stress related skin disorders (but so have placebos).
of us can become so
that we can even
undergo major surgery without anesthesia.
is a split in consciousness, which allows some thoughts and behaviors to occur
Psychological dependence is not the same as physical dependence.
Physical dependence is a physiological need for a drug, marked by unpleasant withdrawal symptoms
when the drug is discontinued.
often refers to stress relieving drugs (like marijuana) that are not physically addictive, yet
can become an important part of the user's life as a way of relieving negative emotions.
Hypnotic pain relief may also result from another form of dual processing known as
Support for this view comes from PET scans showing that
hypnosis reduces brain activity in a region that processes painful stimuli, but not in the sensory cortex
(which receives raw sensory input). This means
hypnosis does not block sensory input, but may block our attention to those stimuli.
Hallucinations without the shrooms