DREAMS
Dream Facts:
• 25% of your night’s sleep or 2 hours is spent dreaming.
• Sleep Thinking – Vague, uncreative, bland thoughts about
real-life events that take place in NREM. Occur more than
dreams.
• Dreams have 5 basic characteristics:
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Emotions can be intense
Content & Organization are usually illogical
Bizarre details are uncritically accepted
Sensations are sometimes bizarre
Dream images are difficult to remember
• Dreams occur in both NREM and REM sleep however they
are more frequent and last longer in REM.
• People usually have 4-5 episodes of dreaming a night.
Dreams happen in real time.
Brain During REM Sleep
•PET scans reveal that brain activity is much different in REM
sleep than when you’re awake.
•Frontal Lobe and Primary Visual Cortex (registers visual info
from retinas) are essentially shut down during REM meaning
you are shut out from the external world and rational thought
so you accept your dreams no matter how bizarre they are.
•Amygdala & hippocampus of the limbic system which deal
with emotion and memory are highly active as are the brain’s
visual areas.
What do we Dream About?
• Most dreams are about everyday life.
• Some themes are found across cultures. (See
Common Dream Themes Table 4.3 pg. 155)
• Aggression is more common than friendliness in
dreams.
• Environmental cues during dreaming may be
incorporated into the dream.
• What you really want to know about dreams? (Read
more - In Focus 4.4, pg. 157)
Why don’t we remember our dreams?
• Areas of the brain used in forming memories (frontal
lobe) are shut down during REM sleep and
neurotransmitters that are used to make memories are
greatly reduced.
• More likely to remember a dream if you wake up
during it.
• Visual encoders tend to be better at remembering
dreams.
• Vivid dreams are more likely to be recalled.
• Distractions when you awaken can cause problems
with remembering dreams.
• Brain seems programmed to forget most of what
occurs during sleep.
Types of Dreams
•True dream—vivid, detailed dreams
consisting of sensory and motor sensations
experienced during REM
• Sleep thought—lacks vivid sensory and
motor sensations, is more similar to daytime
thinking, and occurs during slow-wave
sleep
• Lucid dreaming- dreamer controls what
happens in the dream. Learn how here (2 min)
Dream Theories
Psychoanalytic Interpretation
• Sigmund Freud – Dreams are the fulfillment of
wishes. Unacceptable thoughts of sex & aggression
are repressed when you are conscious but come forth
when you are asleep in the form of dreams.
• Dreams were “the royal road to the unconsciousness”
and a “safety valve” that allowed for the release of
unconscious and unacceptable urges.
• Two components of Dreams
• Manifest Content – actual dream images themselves
• Latent Content – Disguised psychological meaning of
the dream.
• Research does not support his theories.
Physiological Function Theory
• Neural activity during REM sleep
provides periodic stimulation of the
brain.
• Helps with neural development &
preserving neural pathways.
Activation Synthesis Model
• Brain activity during sleep produces dream images
(activation) which are combined by the brain into a
dream story (synthesis).
• Meaning is to be found by analyzing the way the
dreamer makes sense of the progression of chaotic
dream images.
OR, to put it another way:
• Activation of brain stem area (Pons) arouse other
brain areas including visual and auditory and limbic
systems.
• Brain responds to these internally created signals and
assigns them meaning using memories, emotions and
sensations.
Activation-Synthesis Theory
• Dreams are
the mind’s
attempt to
make sense
of random
neural firings
in the brain as
one sleeps.
Information-Processing Theory
• Dreams serve an important memory- related
function by sorting and sifting through the
day’s experiences
• Helps with learning NEW info
• Research suggests REM sleep helps
memory storage.
Cognitive Development Theory
• Dreams draw upon a person’s knowledge
and understanding of their experiences and
are useful for cognitive development
REM & Memory Consolidation
• Memory Consolidation – converting new
memories into a long-term, relatively permanent
form.
• REM seems to help with procedural memories
(skills like riding a bike).
• REM seems to improve performance on learned
tasks.
• Brain areas activated during training on a task
actually are reactivated during REM sleep perhaps
stabilizing the neural connections formed in the
recent training experience.
• This has been studies with Rats in a Maze (4 min)
Dream Research
• Play “What’s in a Dream?” (13:00) Segment #14 from
Scientific American Frontiers: Video Collection for
Introductory Psychology (2nd edition).
• Dream research with Alan Alda.
• What happens biologically when we dream during REM
sleep?
• Where do stories of our dreams come from?
• How brains try to make sense of nonsense.
• What kind of tasks are more difficult if you have random
sleep loss?
• Can dreaming help us learn?