Sleep

Sleep
Dr. Suresh Kumar Murugesan PhD

About the Presenter
● Dr.Suresh Kumar Murugesan is a passionate Professor,researcher and
Mental Health Practitioner from Madurai,Tamil Nadu,India
● At present he is heading the department of Psychology,the American
College,Madurai
● He is very keen in learning new research studies in behavioural
Sciences and open to learn.
● His ultimate aim is to make impression in the ﬁeld of Knowledge
● His area of specializations are Psychotherapy,Positive Psychology,
Education Psychology,Cognitive Psychology,Cyber Psychology etc

Disclaimer
● This presentation is prepared
for learning purpose only and all
the photos used in this
presentation are taken from
google image search.
● Due recognition was given to all
the material collected from the
various sources.
● Any name or reference is
missed kindly bring it to the
notice of the presenter for
inclusion

Sleep
Sleep is a naturally recurring state of mind
and body, characterized by altered
consciousness, relatively inhibited sensory
activity, reduced muscle activity and
inhibition of nearly all voluntary muscles
during rapid eye movement sleep, and
reduced interactions with surroundings.

We are spending ⅓ of
our life time for sleep

Sleep is as essential
to survival as food
and water

Sleep is important to a
number of brain
functions

Recent findings
suggest that
sleep plays a
housekeeping
role that
removes toxins
in our brain that
build up while
we are awake

Research shows that a chronic lack of sleep, or
getting poor quality sleep, increases the risk of
disorders including
1. high blood pressure,
2. cardiovascular disease,
3. diabetes,
4. depression, and
5. obesity

Brain and Sleep
Several structures within the brain are involved
with sleep
1. The hypothalamus
2. The suprachiasmatic nucleus
3. The brain stem
4. The thalamus
5. The cerebral cortex
6. The pineal gland
7. The basal forebrain
8. the midbrain
9. The amygdala

The
hypothalamus
The hypothalamus, a
peanut-sized structure
deep inside the brain,
contains groups of nerve
cells that act as control
centers affecting sleep and
arousal.

SCN
Within the hypothalamus is the
suprachiasmatic nucleus (SCN) – clusters
of thousands of cells that receive
information about light exposure directly
from the eyes and control our behavioral
rhythm. Some people with damage to the
SCN sleep erratically throughout the day
because they are not able to match their
circadian rhythms with the light-dark cycle.
Most blind people maintain some ability to
sense light and are able to modify their
sleep/wake cycle.

Brain Stem 1. The brain stem, at the base of the brain, communicates
with the hypothalamus to control the transitions between
wake and sleep.
2. The brainstem includes structures called the pons,
medulla, and midbrain.
3. Sleep-promoting cells within the hypothalamus and the
brain stem produce a brain chemical called GABA,
which acts to reduce the activity of arousal centers in the
hypothalamus and the brain stem.
4. The brain stem (especially the pons and medulla) also
plays a special role in REM sleep;
5. it sends signals to relax muscles essential for body
posture and limb movements, so that we don’t act out
our dreams.

Thalamus
1. The thalamus acts as a relay for information from
the senses to the cerebral cortex
2. the covering of the brain that interprets and
processes information from short- to long-term
memory
3. During most stages of sleep, the thalamus becomes
quiet, letting you tune out the external world.
4. But during REM sleep, the thalamus is active,
sending the cortex images, sounds, and other
sensations that fill our dreams.

Pineal Gland 1. The pineal gland, located within the brain’s
two hemispheres, receives signals from the
SCN and increases production of the
hormone melatonin, which helps put us to
sleep once the lights go down.
2. People who have lost their sight and cannot
coordinate their natural wake-sleep cycle
using natural light can stabilize their sleep
patterns by taking small amounts of
melatonin at the same time each day.
3. Scientists believe that peaks and valleys of
melatonin over time are important for
matching the body’s circadian rhythm to the
external cycle of light and darkness.

Basal
forebrain
1. The basal forebrain, near the front and
bottom of the brain, also promotes sleep
and wakefulness, while part of the
midbrain acts as an arousal system.
2. Release of adenosine (a chemical
by-product of cellular energy
consumption) from cells in the basal
forebrain and probably other regions
supports your sleep drive.
3. Caffeine counteracts sleepiness by
blocking the actions of adenosine.

Amygdala
The amygdala, an
almond-shaped structure
involved in processing
emotions, becomes
increasingly active during REM
sleep.

Types of Sleep
There are two basic types of sleep:
1. rapid eye movement (REM) sleep and
2. non-REM sleep (which has three
different stages).
Each is linked to specific brain waves and
neuronal activity.
We all cycle through all stages of non-REM
and REM sleep several times during a typical
night, with increasingly longer, deeper REM
periods occurring toward morning.

Stage One Sleep
Stage 1 non-REM sleep is the changeover from wakefulness to
sleep.
During this short period (lasting several minutes) of relatively light
sleep.
Our brain waves begin to slow from their daytime wakefulness
patterns.

During stage one sleep
● Heartbeat slows down
● Breathing slows down
● Eye movements slow down
● Muscles relax and might
occasionally twitch
● Brain waves begin to slow down

How Stage One Sleep
Feels?
According to Harvard Health Publishing, it’s usually
easy to wake someone from stage one sleep, but not
everyone will experience waking up from stage one in
the same way:
“If awakened, one person might recall being drowsy,
while another might describe having been asleep.”

Stage 2 1. Stage 2 non-REM sleep is a period of light
sleep before we enter deeper sleep lasting
10 to 25 minutes
2. Our heartbeat and breathing slow, and
muscles relax even further.
3. Our body temperature drops and eye
movements stop.
4. Brain wave activity slows but is marked by
brief bursts of electrical activity.
5. We spend more of our repeated sleep cycles
in stage 2 sleep than in other sleep stages.

During Stage Three
Sleep
● Heartbeat and breathing slow down even more
● Muscles relax even more
● Body temperature drops
● Eye movements stop
● Brainwave activity slows. The National Institute of Neurological Disorders
and Stroke says brainwave patterns are “marked by brief bursts of
electrical activity

How Stage Two
Sleep Feels?
It’s not as easy to wake someone from stage two sleep as it is from stage one
sleep.
However, stage two sleep is still a fairly light stage of sleep.
People won’t feel disoriented if they wake up from stage two sleep.

Stage 3
1. Stage 3 non-REM sleep is the
period of deep sleep that we need
to feel refreshed in the morning.
2. It lasts 20 to 40 minutes
3. It occurs in longer periods during
the first half of the night.
4. Our heartbeat and breathing slow
to their lowest levels during sleep.
5. Our muscles are relaxed and it may
be difficult to awaken you. Brain
waves become even slower.

During stage Three sleep
● Heartbeat and breathing slow to the lowest levels
they will reach during sleep
● Muscles stay relaxed
● It might be difficult to wake up
● Brain waves slow down even more

How Stage
Three Sleep
Feels?
Stage three sleep is very deep and hard to
wake someone up from — people may not
notice loud noises, bright lights, or other
things that might easily wake them from a
lighter sleep.
“As NREM sleep progresses, the brain
becomes less responsive to external stimuli,
and it becomes increasingly difficult to awaken
an individual from sleep,”
Harvard Health Publishing explains. If
someone is woken from stage three sleep,
they will probably feel groggy and
disoriented.

Stage 4 REM
1. REM sleep,or Rapid Eye Movement sleep,is a very“active”stage.
2. REM sleep ﬁrst occurs about 90 minutes after falling asleep.
3. Our eyes move rapidly from side to side behind closed eyelids.
4. Mixed frequency brain wave activity becomes closer to that seen in wakefulness.
5. Our breathing becomes faster and irregular,and our heart rate and blood pressure increase to near waking
levels.
6. Most of our dreaming occurs during REM sleep,although some can also occur in non-REM sleep.
7. Our arm and leg muscles become temporarily paralyzed,which prevents us from acting out our dreams.
8. As we age,we sleep less of our time in REM sleep.
9. Memory consolidation most likely requires both non-REM and REM sleep.

During REM
sleep
● Behind the eyelids, the eyes move rapidly from
side to side
● Breathing speeds up and can become irregular
● Heart rate increases
● Blood pressure increases
● The majority of vivid dreaming occurs in this
state
● Arms and leg muscles become temporarily
paralyzed. The National Institute of
Neurological Disorders and Stroke explains
that this “prevents you from acting out your
dreams”

How REM Sleep
Feels?
According to Medical News Today,
people experience REM sleep several
times every night, and REM sleep
accounts for “approximately 20 to 25
percent of an adult’s sleep cycle.”
REM stages will probably get longer as
the night goes on. And the NIH explains
that “REM is thought to be involved in
the process of storing memories,
learning, and balancing your mood,
although the exact mechanisms are not
well understood.”

Sleep mechanism
Two internal biological mechanisms–circadian
rhythm and homeostasis–work together to regulate
when you are awake and sleep.

Circadian
rhythms
● Circadian rhythms direct a wide variety of functions from
daily fluctuations in wakefulness to body temperature,
metabolism, and the release of hormones.
● They control your timing of sleep and cause us to be
sleepy at night and our tendency to wake in the morning
without an alarm.
● Our body’s biological clock, which is based on a roughly
24-hour day, controls most circadian rhythms.
● Circadian rhythms synchronize with environmental cues
(light, temperature) about the actual time of day, but they
continue even in the absence of cues.

Sleep-wake
homeostasis
1. Sleep-wake homeostasis keeps track of our need for sleep.
2. The homeostatic sleep drive reminds the body to sleep after a certain
time and regulates sleep intensity.
3. This sleep drive gets stronger every hour we are awake and causes us to
sleep longer and more deeply after a period of sleep deprivation.
4. Factors that influence our sleep-wake needs include medical conditions,
medications,stress,sleep environment,and what we eat and drink.
5. Perhaps the greatest influence is the exposure to light.
6. Specialized cells in the retinas of our eyes process light and tell the
brain whether it is day or night and can advance or delay our sleep-wake
cycle.
7. Exposure to light can make it difficult to fall asleep and return to sleep
when awakened.
8. Night shift workers often have trouble falling asleep when they go to
bed,and also have trouble staying awake at work because their natural
circadian rhythm and sleep-wake cycle is disrupted.
9. In the case of jet lag,circadian rhythms become out of sync with the
time of day when people fly to a different time zone,creating a
mismatch between their internal clock and the actual clock.

Brain Waves
At the root of all our thoughts, emotions and behaviours is
the communication between neurons within our brains.
Brainwaves are produced by synchronised electrical
pulses from masses of neurons communicating with each
other.

Brain Waves
Brainwaves are detected using sensors placed on the
scalp. They are divided into bandwidths to describe their
functions (below), but are best thought of as a
continuous spectrum of consciousness; from slow, loud
and functional - to fast, subtle, and complex.

Brain Waves
It is a handy analogy to think of brainwaves as
musical notes - the low frequency waves are
like a deeply penetrating drum beat, while the
higher frequency brainwaves are more like a
subtle high pitched flute. Like a symphony, the
higher and lower frequencies link and cohere
with each other through harmonics.

Brain Waves
Our brainwaves change according to what we’re doing and
feeling. When slower brainwaves are dominant we can feel
tired, slow, sluggish, or dreamy. The higher frequencies are
dominant when we feel wired, or hyper-alert.

Brain Waves
The descriptions that follow are only broad
descriptions - in practice things are far more
complex, and brainwaves reflect different
aspects when they occur in different locations in
the brain.
Brainwave speed is measured in Hertz (cycles
per second) and they are divided into bands
delineating slow, moderate, and fast waves.

How are brain waves measured?
A test called an electroencephalogram (EEG) can evaluate the
electrical activity in your brain and record the waves, which are
measured in cycles per second, or Hertz (Hz).
Different waves occur at different times, based on what you’re
doing and how you’re feeling.

INFRA-LOW
(<.5HZ)
Infra-Low brainwaves (also known as Slow Cortical
Potentials), are thought to be the basic cortical
rythms that underlie our higher brain functions. Very
little is known about infra-low brainwaves. Their
slow nature make them difficult to detect and
accurately measure, so few studies have been
done. They appear to take a major role in brain
timing and network function.

DELTA WAVES (.5 TO 3
HZ)
Delta brainwaves are slow, loud brainwaves (low
frequency and deeply penetrating, like a drum
beat). They are generated in deepest meditation
and dreamless sleep. Delta waves suspend
external awareness and are the source of empathy.
Healing and regeneration are stimulated in this
state, and that is why deep restorative sleep is so
essential to the healing process.

THETA
WAVES (3
TO 8 HZ)
Theta brainwaves occur most often in sleep but are also
dominant in deep meditation. Theta is our gateway to learning,
memory, and intuition. In theta, our senses are withdrawn from
the external world and focused on signals originating from
within. It is that twilight state which we normally only
experience fleetingly as we wake or drift off to sleep. In theta
we are in a dream; vivid imagery, intuition and information
beyond our normal conscious awareness. It’s where we hold
our ‘stuff’, our fears, troubled history, and nightmares.

ALPHA WAVES (8 TO 12
HZ)
Alpha brainwaves are dominant during quietly
flowing thoughts, and in some meditative states.
Alpha is ‘the power of now’, being here, in the
present. Alpha is the resting state for the brain.
Alpha waves aid overall mental coordination,
calmness, alertness, mind/body integration and
learning.

BETA WAVES (12 TO 38
HZ)
Beta brainwaves dominate our normal waking state of
consciousness when attention is directed towards cognitive
tasks and the outside world. Beta is a ‘fast’ activity, present
when we are alert, attentive, engaged in problem solving,
judgment, decision making, or focused mental activity.
Beta brainwaves are further divided into three bands;
Lo-Beta (Beta1, 12-15Hz) can be thought of as a 'fast idle',
or musing. Beta (Beta2, 15-22Hz) is high engagement or
actively figuring something out. Hi-Beta (Beta3, 22-38Hz) is
highly complex thought, integrating new experiences, high
anxiety, or excitement. Continual high frequency processing
is not a very efficient way to run the brain, as it takes a
tremendous amount of energy.

GAMMA
WAVES (38
TO 42 HZ)
Gamma brainwaves are the fastest of brain waves (high
frequency, like a flute), and relate to simultaneous processing
of information from different brain areas. Gamma brainwaves
pass information rapidly and quietly. The most subtle of the
brainwave frequencies, the mind has to be quiet to access
gamma.
Gamma was dismissed as 'spare brain noise' until researchers
discovered it was highly active when in states of universal
love, altruism, and the ‘higher virtues’. Gamma is also above
the frequency of neuronal firing, so how it is generated
remains a mystery. It is speculated that gamma rhythms
modulate perception and consciousness, and that a greater
presence of gamma relates to expanded consciousness and
spiritual emergence.

Frequency band Frequency Brain states
Gamma (γ) >35 Hz Concentration
Beta (β) 12–35 Hz Anxiety dominant, active, external attention,
relaxed
Alpha (α) 8–12 Hz Very relaxed, passive attention
Theta (θ) 4–8 Hz Deeply relaxed, inward focused
Delta (δ) 0.5–4 Hz Sleep

WHAT BRAINWAVES MEAN TO US
Our brainwave profile and our daily experience of the world are inseparable. When our brainwaves are out of balance,
there will be corresponding problems in our emotional or neuro-physical health. Research has identified brainwave patterns
associated with all sorts of emotional and neurological conditions.
Over-arousal in certain brain areas is linked with anxiety disorders, sleep problems, nightmares, hyper-vigilance, impulsive
behaviour, anger/aggression, agitated depression, chronic nerve pain and spasticity. Under-arousal in certain brain areas
leads to some types of depression, attention deficit, chronic pain and insomnia. A combination of under-arousal and
over-arousal is seen in cases of anxiety, depression and ADHD.
Instabilities in brain rhythms correlate with tics, obsessive-compulsive disorder, aggressive behaviour, rage, bruxism, panic
attacks, bipolar disorder, migraines, narcolepsy, epilepsy, sleep apnea, vertigo, tinnitus, anorexia/bulimia, PMT, diabetes,
hypoglycaemia and explosive behaviour.

ALTERING YOUR BRAINWAVES
By rule of thumb, any process that changes your perception changes your brainwaves.
Chemical interventions such as medications or recreational drugs are the most common methods to alter brain function;
however brainwave training is our method of choice.
Over the long term, traditional eastern methods (such as meditation and yoga) train your brainwaves into balance. Of the
newer methods, brainwave entrainment is an easy, low-cost method to temporarily alter your brainwave state. If you are
trying to solve a particular difficulty or fine-tune your brainwave function, state-of-the-art brain training methods like
neurofeedback and pEMF deliver targeted, quick, and lasting results.

How Much
Sleep Do we
Need?
1. Our need for sleep and our sleep patterns change as we age,but this
varies signiﬁcantly across individuals of the same age.
2. There is no magic“number of sleep hours”that works for everybody of
the same age.
3. Babies initially sleep as much as 16 to 18 hours per day,which may
boost growth and development (especially of the brain).
4. School-age children and teens on average need about 9.5 hours of sleep
per night.
5. Most adults need 7-9 hours of sleep a night,but after age 60,nighttime
sleep tends to be shorter,lighter,and interrupted by multiple
awakenings.
6. Elderly people are also more likely to take medications that interfere
with sleep.
7. In general,people are getting less sleep than they need due to longer
work hours and the availability of round-the-clock entertainment and
other activities.
8. Many people feel they can "catch up"on missed sleep during the
weekend but,depending on how sleep-deprived they are,sleeping
longer on the weekends may not be adequate.

Dreaming 1. Everyone dreams.
2. We spend about 2 hours each night
dreaming but may not remember most of our
dreams.
3. Its exact purpose isn’t known, but dreaming
may help us process our emotions.
4. Events from the day often invade our
thoughts during sleep, and people suffering
from stress or anxiety are more likely to have
frightening dreams.
5. Dreams can be experienced in all stages of
sleep but usually are most vivid in REM
sleep.
6. Some people dream in color, while others
only recall dreams in black and white.

The Role of Genes
and
Neurotransmitters

1 2 3 4
Chemical signals to sleep
Clusters of
sleep-promoting neurons
in many parts of the brain
become more active as we
get ready for bed.
Nerve-signaling chemicals
called neurotransmitters
can “switch off” or dampen
the activity of cells that
signal arousal or
relaxation.
GABA is associated with
sleep, muscle relaxation,
and sedation.
Norepinephrine and orexin
(also called hypocretin)
keep some parts of the
brain active while we are
awake.
Other neurotransmitters
that shape sleep and
wakefulness include
acetylcholine, histamine,
adrenaline, cortisol, and
serotonin.

Genes and sleep
1. Genes may play a significant role in how much sleep we need.
2. Scientists have identified several genes involved with sleep
and sleep disorders,including genes that control the
excitability of neurons,and "clock"genes such as Per,tim,and
Cry that influence our circadian rhythms and the timing of
sleep.
3. Genome-wide association studies have identified sites on
various chromosomes that increase our susceptibility to sleep
disorders.
4. Also,different genes have been identified with such sleep
disorders as familial advanced sleep-phase disorder,
narcolepsy,and restless legs syndrome.
5. Some of the genes expressed in the cerebral cortex and other
brain areas change their level of expression between sleep and
wake.
6. Several genetic models–including the worm,fruit fly,and
zebrafish–are helping scientists to identify molecular
mechanisms and genetic variants involved in normal sleep and
sleep disorders.
7. Additional research will provide better understand of inherited
sleep patterns and risks of circadian and sleep disorders.

Sleep studies 1. Our health care provider may recommend a
polysomnogram or other test to diagnose a sleep
disorder.
2. A polysomnogram typically involves spending the
night at a sleep lab or sleep center.
3. It records our breathing, oxygen levels, eye and limb
movements, heart rate, and brain waves throughout
the night.
4. Our sleep is also video and audio recorded.
5. The data can help a sleep specialist determine if we
are reaching and proceeding properly through the
various sleep stages.
6. Results may be used to develop a treatment plan or
determine if further tests are needed.

Tracking Sleep
Through Smart
Technology
Millions of people are using smartphone apps,
bedside monitors, and wearable items (including
bracelets, smart watches, and headbands) to
informally collect and analyze data about their
sleep.
Smart technology can record sounds and
movement during sleep, journal hours slept, and
monitor heartbeat and respiration.
Using a companion app, data from some devices
can be synced to a smartphone or tablet, or
uploaded to a PC. Other apps and devices make
white noise, produce light that stimulates melatonin
production, and use gentle vibrations to help us
sleep and wake.

Tips for Getting a
Good Night's Sleep
1. Set a schedule – go to bed and wake up at the
same time each day.
2. Exercise 20 to 30 minutes a day but no later than a
few hours before going to bed.
3. Avoid caffeine and nicotine late in the day and
alcoholic drinks before bed.
4. Relax before bed – try a warm bath, reading, or
another relaxing routine.
5. Create a room for sleep – avoid bright lights and
loud sounds, keep the room at a comfortable
temperature, and don’t watch TV or have a computer
in your bedroom.
6. Don’t lie in bed awake. If you can’t get to sleep, do
something else, like reading or listening to music,
until you feel tired.
7. Consult Psychologist if you have a problem
sleeping or if you feel unusually tired during the day.
Most sleep disorders can be treated effectively.

Hope
Through
Research
1. Scientists continue to learn about the function and regulation of
sleep.
2. A key focus of research is to understand the risks involved with
being chronically sleep deprived and the relationship between
sleep and disease.
3. People who are chronically sleep deprived are more likely to be
overweight,have strokes and cardiovascular disease,infections,and
certain types of cancer than those who get enough sleep.
4. Sleep disturbances are common among people with age-related
neurological disorders such as Alzheimer’s disease and Parkinson’s
disease.
5. Many mysteries remain about the association between sleep and
these health problems.
6. Does the lack of sleep lead to certain disorders,or do certain
diseases cause a lack of sleep?
7. These,and many other questions about sleep,represent the frontier
of sleep research.

References 1. https://en.wikipedia.org/wiki/Sleep
2. https://www.ninds.nih.gov/Disorders/patient-caregiver-ed
ucation/understanding-sleep
3. https://www.sleepassociation.org/about-sleep/what-is-sl
eep/
4. http://healthysleep.med.harvard.edu/healthy/science/wh
at
5. https://www.mattressclarity.com/blog/sleep-cycle/
6. https://www.verywellhealth.com/the-four-stages-of-sleep
-2795920
7. https://www.sleepfoundation.org/articles/stages-of-sleep
8. https://brainworksneurotherapy.com/what-are-brainwave
s
9.

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