The document discusses various aspects of consciousness, sleep, and dreams. It begins by defining consciousness and describing different levels of consciousness such as waking, subconscious, and unconscious states. It then discusses sleep stages and brain wave patterns associated with each stage. REM sleep is specifically called out as the stage where most vivid dreams occur. The document also covers sleep disorders, the effects of sleep deprivation, and theories about the purpose and meaning of dreams.
4. Integrated Information Theory of
Consciousness
Consciousness can exist to varying
degrees depending on the person, time of
day, distractions, amount of sleep or food,
mental and physical illness, medicine, etc.
In order to be conscious the brain
integrates a complex web of information
from sensory systems and cognitive
processes. Cerebrum, somatosensory,
frontal lobe…what other areas?
7. Introspection
• The only direct way to study consciousness
is to have people look within themselves, or
introspect.
• Introspection is a powerful research tool—
but it is limited.
• People often lack words for
experiences.
• Different individuals may use the same
words to describe different
experiences.
8. Mistaken Introspections
• Introspections are also sometimes mistaken.
• People don’t realize what factor
influenced their thoughts or behavior.
• Or they insist a factor influenced them
even though it didn’t.
• These cases suggest introspection
often is people’s best after-the-fact
estimation of why they acted or felt the
way they did.
9. Brain Areas
The amygdala regulates emotions and fight or
flight type responses. It also helps in the
formation of emotional memories.
The hippocampus helps store (consolidate)
episodic memories meaning your autobiography,
perceptions, and the emotions associated with
these memories.
The exact content of consciousness depends on
diverse brain sites and what a person is
conscious of.
10.
11. Varieties of Consciousness
• Our conscious state changes when we’re
asleep.
• EE`G data allows us to distinguish distinct
stages of sleep.
• People seem to need an adequate amount of
sleep as well as the right amount of both
slow-wave and REM sleep.
12. Sleep
Why do we need to sleep?
Sleep helps our brain consolidate learning and
memories. Our bodies also need to sleep to
rejuvenate, grow muscle, repair, and to pay
attention.
https://www.ted.com/talks/russell_foster_w
hy_do_we_sleep?language=en
13. Figure 4.2
This chart illustrates the circadian change in body temperature over 28 hours in a
group of eight young men. Body temperature rises throughout the waking day,
peaking in the afternoon, and falls during sleep with the lowest point occurring
during the very early morning hours.
14. Figure 4.3
The suprachiasmatic nucleus (SCN) serves as the brain’s clock mechanism. The
clock sets itself with light information received through projections from the retina.
15. Sleep Deprivation and
Consciousness
Sleep deprivation occurs when an individual fails
to get enough sleep. The amount of sleep that a
person needs varies from one person to
another, but on average most adults need about
seven to eight hours of sleep each night to feel
alert and well rested.
https://youtu.be/JWKDgs9bMws
16. Figure 4.4
Devices like this are designed to provide exposure to bright light to help people
maintain a regular circadian cycle. They can be helpful for people working night
shifts or for people affected by seasonal variations in light.
17. Figure 4.5
This figure illustrates some of the negative consequences of sleep deprivation.
While cognitive deficits may be the most obvious, many body systems are
negatively impacted by lack of sleep. (credit: modification of work by Mikael
Häggström)
18. Figure 4.6
This is a segment of a polysonograph (PSG), a recording of several physical variables during
sleep. The x-axis shows passage of time in seconds; this record includes 30 seconds of data.
The location of the sets of electrode that produced each signal is labeled on the y-axis. The red
box encompasses EEG output, and the waveforms are characteristic of a specific stage of
sleep. Other curves show other sleep-related data, such as body temperature, muscle activity,
and heartbeat.
19. Figure 4.7
The pineal and pituitary glands secrete a number of hormones during sleep.
20. Figure 4.8
Brainwave activity changes dramatically across the different stages of sleep. (credit
“sleeping”: modification of work by Ryan Vaarsi)
21. Figure 4.9
Brainwave activity changes dramatically across the different stages of sleep.
22. Figure 4.10
Stage 2 sleep is characterized by the appearance of both sleep spindles and K-
complexes.
23. Sleep Disorders
Nightmares are dreams with vivid and disturbing
content. They are most common
inchildren during REM sleep, but they can
happen to adults as well. They usually involve
and immediate awakening and good recall of the
dream. Sleep terrors, also common in children,
are often described as extreme nightmares that
take place during non-REM sleep.
24. Sleep Disorders
Sleep terrors have common
characteristics. They usually include
arousal, agitation, large pupils, sweating,
and increase blood pressure. Usually the
child screams and appears terrified for
several minutes until they eventually relax
and return to sleep. Sleep terrors usually
take place early in the night and may be
combined with sleepwalking. The child
typically does not remember or only has a
vague memory of their dream.
28. Quiz 4
What are three types of brain waves?
Why do we need REM sleep?
29. Dreams
• Dreams are associated with REM sleep.
• Dream showcase a range of ordinary preoccupations,
but they also include weird elements like being naked
in public.
• Many people propose that dreams have hidden
meaning.
• Most researchers say they are just a hodgepodge
of activated images made into a narrative by the
sleeping brain or the person recalling the dream.
30. Altered States of Consciousness
Sleep and Dreams
Hypnosis
Chemically altered states
31. Sleep and Dreams
Sleep
periodic, natural, reversible loss of
consciousness
Circadian Rhythm
the biological clock
regular bodily rhythms that occur on
a 24-hour cycle, such as of
wakefulness and body temperature
32. Sleep and Dreams
Stage 1
Lasts up to 5 minutes
Hallucinations
Hypnogogic experience
Stage 2
20 minutes
Sleep spindles
Sleep talking may occur
33. Sleep and Dreams
Stage 3
Transitional stage
Lasts only a few minutes
Stage 4
Brain emits delta waves
Lasts 30 minutes
Sleep walking, bed wetting may occur
You can still process the outside world
34. Brain Waves and Sleep
Stages
Alpha Waves
slow waves of a
relaxed, awake
brain
Delta Waves
large, slow waves
of deep sleep
35. Stages in a Typical Night’s
Sleep
0 1 2 3 4 5 6 7
4
3
2
1
Sleep
stages
Awake
Hours of sleep
REM
36. Stages in a Typical Night’s
Sleep
Hours of sleep
Minutes
of
Stage 4
and
REM
1 2 3 4 5 6 7 8
0
10
15
20
25
5
Decreasing
Stage 4
Increasing
REM
37. Sleep and Dreams
REM (Rapid Eye Movement) Sleep
recurring sleep stage
vivid dreams
“paradoxical sleep”
muscles are generally relaxed, but other
body systems are active
38. Sleep Deprivation
Effects of Sleep
Loss
fatigue
impaired
concentration
depressed immune
system
greater vulnerability
to accidents
39. Sleep Disorders
Insomnia
persistent problems in falling or staying
asleep
Narcolepsy
uncontrollable sleep attacks
Sleep Apnea
temporary cessation of breathing
momentary reawakenings
40. Night Terrors and
Nightmares
Night Terrors
occur within 2 or
3 hours of falling
asleep, usually
during Stage 4
high arousal--
appearance of
being terrified
0 1 2 3 4 5 6 7
4
3
2
1
Sleep
stages
Awake
Hours of sleep
REM
42. Dreams: Freud
Sigmund Freud--The Interpretation of
Dreams (1900)
wish fulfillment
discharge otherwise unacceptable
feelings
Manifest Content
remembered story line
Latent Content
underlying meaning
43. Dreams: Freud
Dreams
Dream is a safe outlet for the mind
Deals with unacceptable thoughts and
emotions
Manifest content is the “dressed up”
symbolic version of the unconscious
Most adult dreams have strong sexual
undertones
Dream interpenetration is the “royal road
to the unconscious”
44. Dreams: Information
processing
As Information Processing
Dreams serve to sift and sort
memories of our daily experiences
Helps us to better process and store
memories and learning from the
previous day
45. Dreams: Information
processing
Support for theory
REM sleep increases following a stressful
experience and intense learning experiences
People will perform worse on a memory test if
kept from dreaming the night before
46. Dreams: Activation-synthesis
Neural activity is random and dreams are
your brain’s attempt to make sense of it
Your brain tries to impose meaning on
meaningless stimuli
47. Dreams: Activation-synthesis
Support
Eye movement of REM sleep coincides with
bursts of neural activity in the visual cortex
Would account for random and bizarre
occurrences in dreams
48. Dreams: Physiological Function
Dreams serve to provide neural
stimulation for a sleeping brain
Stimulation of the neural pathways
strengthens connections and makes
processing faster and more efficient
49. Dreams: Physiological Function
Support
Infants and children experience longer
periods of REM sleep than adults.
REM sleep periods decrease as we age