1. By Avinash Ambati
ECE- III year
VNR Vignana Jyothi Inst & Tech

2. Sleep is the regular state of
SLEEP
natural rest observed in all
mammals, birds and
fish. Sleep is not actually "
unconsciousness," but
rather, it is a natural state of
rest characterized by a
reduction in voluntary body
movement and decreased
awareness of the
surroundings. Therefore,
since consciousness is
literally the awareness of the
surroundings, being asleep is
just an altered state of
consciousness, as opposed
to being unconscious. It is
heavily influenced by
circadian rhythms.

3. HORMONES CAUSING SLEEP
The cycle of sleep and wakefulness is regulated by the brain stem, external
stimuli, and various hormones produced by the hypothalamus.
Some neurohormones and neurotransmitters are highly correlated with
sleep and wake states. For example, melatonin levels are highest during
the night, and this hormone appears to promote sleep. Adenosine,
a nucleoside involved in generating energy for biochemical processes,
gradually accumulates in the human brain during wakefulness but
decreases during sleep.

4. Electroencephalogram (EEG)

5. Electrodes placed on the
scalp provide a gross record
of the electrical activity of the
brain
EEG recordings are a
rough index of psychological
states

6. Awake, but non-attentive - Awake, non attentive 1 second
large, regular alpha waves
Alpha waves
Awake and attentive - low
Awake, attentive 1secon
amplitude, fast, irregular beta d
wave
Beta waves

7. Sleep stage 1
Sleep stage 1 - brief transition
stage when first falling asleep
Stages 2 through 4 (slow- Sleep stage 2-4
Sleep stage 2
wave sleep) - successively
deeper stages of sleep
Characterized by an Spindles (bursts of activity
Spindles occur
increasing percentage of slow,
irregular, high-amplitude delta Sleep stage 4
waves
Delta waves

8. Once you have entered Stage 4th stage, your muscles
will be most relaxed and your eyes will begin to move
rapidly. You have entered your most active type of sleep
This Active Sleep is called REM Sleep
Pulse rate and breathing become irregular
This is period of intensely emotional or physical
demanding activity (face and fingers twitch, large
muscles will become paralyzed) Your brain waves are
similar to those of when you are awake Almost all normal
dreaming takes place during REM sleep

9. REM sleep will last from 15 minutes
early in the night to 45 minutes late at
night
You will go through the stages into REM
sleep and then reverse backwards
You go through the cycles about every
90 minutes
At no point is your brain totally inactive
REM sleep seems to serve the functions
of building efficient learning and
memory processing

10. Dreaming: the mental activity that
takes place during sleep
Everybody dreams, but most people are
only able to recall a few, if any, of their
dreams
In some cultures, dreams are highly
valued and frequently discussed so
people will begin to remember them most
mornings

11. As the night continues on,
dreams become longer and
more vivid and dramatic
especially those during REM
sleep
Because of the sleep cycle
usually ends in REM sleep, the
last dream is likely to be the
longest and the one most
people remember when they
wake up

12. when, for instance, the
hungry man dreams he is
eating a wonderful meal, or
the thirsty that they see
sparkling water.
As for example that of the mountain
climber who dreamt he was climbing
higher and higher and gaily stepping
off into space…

13. According to Freud,
dreams were
disguised,
hallucinatory
fulfilment of
repressed wishes.

14. He also asserted that dreams not
only represented current wishes ,

15. but were also invariably
expressions of wish-fulfilments
dating from early childhood .

16. Freud described the
mental processes, or
“dream-work”, by
which the dream was
modified and
rendered less
disturbing.

17. Condensation, the fusing
together of different ideas and
images into a single image;

18. Representation, the
process by which thoughts
are converted into visual
images;

19. Displacement, in
which a potentially
disturbing image or
idea is replaced by
something
connected but less
disturbing;

20. Dreams are not
symptomatic, but
symbolic. The deeper
layers speak in images.

21. UNDERSTANDING UR DREAM
The first step in understanding a
dream is to establish its context. This
means unraveling its network of
relationships with the dreamer and his
or her life, and discovering the
significance of various images it
presents;
e.g., one’s
mother
might
appear in a
dream:

22. Now, everyone
has a concept of
what mother
means, but for
each person the
image of the
mother is
different, and the
significance of
this image will
even vary from
time to time.

23. •Somnambulism - sleepwalking
•Nightmares - frightening dreams that wake a sleeper
from REM
•Night terrors - sudden arousal from sleep and intense
fear accompanied by physiological reactions (e.g., rapid
heart rate, perspiration) that occur during slow-wave sleep
•Narcolepsy - overpowering urge to fall asleep that may
occur while talking or standing up
Sleep apnea - failure to breathe when asleep

24. Hence sleep occurs due to the tiredness of the body and to
relax the stressed body
The Dreams which come in the sleep are due the
sequence of random images which occur during the deep
sleep