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.
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.
– Dream more about failures than successes
– Aggression is more common than friendliness in dreams.
– (See Common Dream Themes Table 4.3 pg. 155)
• Environmental cues during dreaming may be
incorporated into the dream.
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.
– “safety valve” that allowed for the release of unconscious
and unacceptable urges.
• Dreams were “the royal road to the unconsciousness”
• Two components of Dreams
1. Manifest Content – actual dream images themselves
2. Latent Content – Disguised psychological meaning of the
dream.
• Research does not support his theories.
Information-Processing
Theory
• Dreams serve an important memory- related
function by sorting and sifting through the
day’s experiences
• Rehearse Stressful Situations
• Helps with learning NEW info
• Research suggests REM sleep helps memory
storage.
– Areas active during learning also active during dream
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)
Physiological Function Theory
• Neural activity during REM sleep provides
periodic stimulation of the brain.
– Helps with neural development & preserving neural
pathways.
Physiological Function Theory
• Neural activity during REM sleep provides periodic
stimulation of the brain.
Activation Synthesis Model
• Brain activity during sleep produces
dream images (activation) which are
combined by the brain into a dream
story (synthesis). – Bottom-Up
• 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
• Neural
Activation
Theory
• Dreams are
the mind’s
attempt to
make sense
of random
neural firings
in the brain as
one sleeps.
Cognitive Development Theory
• Dreams draw upon a person’s knowledge and
understanding of their experiences and are useful
for cognitive development
• Children dream in pictures while adults dream
with language & conversation being more of a
focal point
• A Top-Down way of dreaming where our concepts
and knowledge simulate our current reality in our
dream
• Our dreams become more mature as we mature.
Dream Research
• Play “What’s in a Dream?” (13:00)
– Segment #14 from Scientific American Frontiers DVD
– 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?