Lecture: Dreaming Flashcards
When does dreaming occur?
Dreaming can occur in REM and non REM (NREM) states
what percentage of our sleep is NREM?
75%
What are NREM dreams like?
tend to be short, dull and undreamlike (e.g., walking, eating, not story like)
What is REM sleep characterized by?
Rem sleep is characterized by rapid eye movement, muscle atonia (temporary paralysis sorta) and often dreaming
What disorders are associated with sleep?
- Muscle atonia is caused by part of the brain called pons
- If you disable the pons in cats, they engage in stalking behaviour during REM.
- REM sleep disorder (paralysis that typically occurs is absent, people act out their dreams)
- Sleepwalking (somnambulism)NREM sleep
What do people who have no dream imagery have?
People who have no dream imagery (visual anoneria) tend to also have a waking deficit in imaging memories (visual irreminisence)
What is our dream recall capability like?
- We typically forget dreams
- Correlates with visuospatial skill and individual differences in working memory
- Animals and infants cannot report dreams
- Commonly people assert that there was much more to their dream than they can report
What are the worst to best ways to record dreams?
- Ask people what their dreams tend to be like
- Ask people to keep a dream diary (a little more systematic)
- Ask people every morning to report their dreams
- Wake people up during sleep at many points during the night and get reports (scientifically best way)
What are dreams like?
- Scene shifts are common
- Tend to be narrative
- Tend to be experienced “first person”
- Dream emotion tends to match content
- Dreams can be bizarre but not often this way
What else are dreams like?
- They are always animated.
- Dreams are rarely bizarre, but when they are we often do not really notice it until we are awake
- Selection bias: bizarre dreams are easier to remember and are more often talked about
What are dreams not like?
- Films, visual images, recent social situations, and pre sleep behaviour are rarely incorporated into dreams
- Recent episodic memories, even salient ones are rarely incorporated
What kind of inferences can dreams get from the world?
- Dreaming you need to urinate
- Dreaming of teeth falling out (which 70% of people do during sleep) caused by dental irritation
How can you affect your dreams?
- Pre-sleep attention to a specific concern
- This is called “dream incubation”
What is threat stimulation theory (TST)?
- By philosopher Antti Revonsuo
- A major function of dreaming is to practice dealing with threats that were common in our ancestral environment
What is the support for TST?
- Animal dreams are highest in kids and decreases with age
- Negative emotions appear twice as often as positive ones in dreams
- The only kind of recurring dream with any frequency is being threatened by animals, monsters, people or natural disasters and the response was watching, Running or hiding.
- Proposed to be for the same reason that children play pretend, to practice for real world situations. It is evolutionary
- Animals dream decrease with age, suggesting its evolutionary. As they learn and get enculturated they stop having these preparation dreams
What is some more support for TST?
-Westerners dream of things we rarely experience -Ancestral threats are overrepresented -People react appropriately to dream threats 94% of the time
Where else are ancient survival behaviours over represented?
- Ancient survival behaviours are also overrepresented in play and in phobias
- Animals play appropriately for what they need to learn to do
What is the dreaming brain like?
- The brainstem is very active, sending information forward
- The DLPFC (involved with executive function) is deactivated
- perhaps explaining our reduced reasoning ability during dreams
- Not noticing what’s weird
- Uninhibited behaviour
- But also our difficulty in remembering dreams
What is the AIM model of conscious state?
- Activation: Basic level of brain activation
- Information flow: Sensory input vs. internal, fictive input
- Model of information processing: Aminergic, cholinergic neuromodulation
- Activation-synthesis hypothesis: Dreams are the cortex trying to make sense of chaotic inputs from the brainstem
What support is there for the activation synthesis hypothesis?
- Dream emotion seems to shape dreams, not the other way around (e.g., an anxiety dream will often shift from one anxiety producing to the other)
- Dream recall cessation is almost always caused by forebrain lesions
What is lucid dreaming?
- When you know you’re dreaming and can control your actions, and sometimes other dream content.
- You can only control your eyes in the real world
- Could be a reactivation of the DLPFC, which allows you to see dream content for what it is, and control yourself.
- Training: dream diaries, reality checks, tech
What is sleep paralysis characterized by?
- You feel awake
- You might feel chest pressure
- You can’t move
- It’s a carryover of muscle atonia from sleep to waking
- You have hallucinations, often of the presence of a malevolent character
- You feel abject terror
