Lecture: Dreaming

Dreaming can occur in REM and non REM (NREM) states

75%

tend to be short, dull and undreamlike (e.g., walking, eating, not story like)

Rem sleep is characterized by rapid eye movement, muscle atonia (temporary paralysis sorta) and often dreaming

• 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

People who have no dream imagery (visual anoneria) tend to also have a waking deficit in imaging memories (visual irreminisence)

• 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

• 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)

• 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

• 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

• Films, visual images, recent social situations, and pre sleep behaviour are rarely incorporated into dreams • Recent episodic memories, even salient ones are rarely incorporated

• Dreaming you need to urinate - Dreaming of teeth falling out (which 70% of people do during sleep) caused by dental irritation

• Pre-sleep attention to a specific concern - This is called “dream incubation”

• By philosopher Antti Revonsuo - A major function of dreaming is to practice dealing with threats that were common in our ancestral environment

• 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

-Westerners dream of things we rarely experience -Ancestral threats are overrepresented -People react appropriately to dream threats 94% of the time

• Ancient survival behaviours are also overrepresented in play and in phobias • Animals play appropriately for what they need to learn to do

• 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

• 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

• 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

• 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

• 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