Sleep and Dreams

Question 1

Sigmund Freud and Dreams
(The Interpretation of Dreams, published in 1899)
- what content
- according to freud, what 2 functions do dreams have?

Answer 1

– Manifest and latent content (the actual meaning that needed interpretation by a psychoanalyst, through sessions involving free association)
– According to Freud dreams have two functions:
a) to let repressed desires and conflicts be expressed
b) to protect sleep from being disturbed (in dreams, the truth is distorted, so dreams are the ‘guardians’ of sleep)
– Rather poorly received by the medical, scientific and psychiatric community

Question 2

Freud- 2 types of content of dreams

Answer 2

1- manifest content- the one we describe to others and what we experience in dreams
2- latent- behind the secret meaning of the dreams

Question 3

Freud’s Predecessors (2)

Answer 3

Alfred Maury (1817-1892) – ‘Sleep and Dreams’, 1861
- Conducted a series of experiments using himself as the subject
- Concluded that we incorporate into our dreams sensory information, i.e. sirens, alarm clock, feeling wet, etc.

Mary Whiton Calkins (1863-1930) – ‘Statistics of Dreams’, 1893
- Took dream reports and saw that there was congruity and continuity, in that elements of waking life are integrated into our dreams which became known as the continuity hypothesis

Question 4

Sante de Sanctis (1862-1935)
What did they do and find?

Answer 4

Used electrophysiological instruments such as the esthesiometer to measure sleep depth through the presentation of tactile stimulation and the thoracic pneumonograph to check on breathing patterns

Noticed that:
— Dreaming was less common during deep sleep compared to light sleep
— Dreams were more vivid in the lighter sleep (end of the night) and during bouts of irregular breathing

Question 5

Sante de Sanctis (1862-1935)
Formula he came up with

Answer 5

To understand a dream, one has to regard it as the sum of certain factors

The fundamental state of the dreamer (past experiences, intelligence, character, old habits)
+
The state of the moment (aspirations, passions, state of health conditions of the organs and devices)
+
Immediate experiences provoked by extrinsic conditions (during sleep)

Question 6

Santiago Ramon y Cajal

Answer 6

Very eager to prove Freud wrong, he kept a dream journal for 16 years (1918-1934)

He said brains made up of distinct neurons and they are not interconnected

He was more focused on creating sensational theory rather than an evidenced based, scientific theory about dreams

Question 7

What is a dream?

Answer 7

Any mental experience that occurs during sleep, thoughts, feelings or images (sensations) that come into our awareness while we sleep, and which arise internally

Dreams can be complex or really simple- a continuum ranging from isolated sensations or thoughts to wild and complex plots

Question 8

Where does the content come from?
- what are dreams made up from?
- what do we tend to do?
- what are more likely to be incorporated into our dreams
- what did Mark Blagrove do and find?

Answer 8

• Dreams seem to incorporate events from a couple of days before (day-residue) or from several (5-7) days before the dream (dream-lag) (Eichenlaub et al, 2019)
• We tend to incorporate certain aspects of our experiences, objects, people, settings etc and these are combined with older memories, weakly related memories
• The most emotionally salient elements are more likely to be incorporated into our dreams
• Mark Blagrove (Swansea) asked participants to rate the emotional intensity of the main events in their day and later found that the most emotional events tended to be incorporated in REM dreams more than those less emotional (Eichenlaub et al, 2018)

Dream lag: could be recent but also could be from 5-7 days back

Question 9

Three ways of responding when waking?

Answer 9

a) They do not remember dreaming

b) They know they were dreaming but they don’t remember the content (‘white dream’)

c) They remember both (dreaming and the dream)

• It may be that what/how we ask influences the answer we get. May be useful to use specific probes
• i.e. specific instructions, about smell and taste, because we generally do not talk in terms of these senses

Question 10

When do we dream?
1- What did Aserinksi and Kleitman (1953) report
2- What did Dement and Kleitman (1957) report
3- dreaming during NREM N2
4- dreaming during NREM N1
5- dreaming during NREM N3
6- shortness of reports N1/N2/N3

Answer 10

1- Aserinksi and Kleitman (1953) - reported the discovery of dreaming during REM and its cyclical nature of ~90m
2- Dement and Kleitman (1957) reported that dreaming occurred more during REM compared to NREM (80% vs 7%) (When we wake up ppl from rem 80% report they are dreaming but waking them up during non rem only 7% report they are dreaming)
3- Gradually, dreaming during NREM 2 increased from 7% in the original report to 50-70%
4- During NREM N1 rates are even higher (~75%) dreams in the first minutes of sleep, known as ‘hypnagogic’ dreams (hypnagogic = hypnos + agogos)
5- During NREM N3 dreaming occurs ~ 50% of the time
6- N1 reports are shorter than N2 reports, which are shorter than REM. Most of our dreams occur during REM and NREM1 and less during NREM2 and NREM3

Question 11

Do all humans dream?

Answer 11

• At least 85-90% of adults say that they dream
  – The average person recalls about 4-6 dreams a month.
• Most of those who say that they never dream, actually do when they are studied in a sleep lab and are awakened from REM sleep.
  – They just don’t remember their dreams after waking up
• Jim Pagel (U of Colorado) studies non-dreamers and over a period of 5 years he found 16 patients (1:200 patients) who reported that they never dream
  – So maybe 0.5% of adults cannot remember their dreams or may never dream

Question 12

Dream Content Scales

Answer 12

Calvin Hall and Robert Van de Castle created the HVC Scale (1966) which is the best validated dream-scoring system

• analyzed 1000 dreams: 5 dream reports collected from 100 men and 100 women college students in great detail
• Hall’s findings also supported the ‘continuity hypothesis’ of dreams
• Based on patterns of dream content tried to infer dreamer’s personality, conflict, concerns ect.

Question 13

Strauch and Meier, 1996: summarised their findings on 500 REM awakening reports with a morning follow-up from 44 young adults

What did they find on average and secondary

Answer 13

On average:
- 2.6 characters
- 4.8 activities
- 1.4 social interactions
- 1.3 settings
- 75% contained emotions and negative aspects
- Less than half had misfortunes
- 10% failure, success or good fortune

The setting is secondary:
- 44% unknown settings (unsure where they were)
- 26% familiar settings
- 19% vague and non-specific settings
- 11% distorted
- 1% fictional or fantasy

in 25% the setting changed before the end of the dream

Question 14

Characters in Dreams
- what is the dreamer often?
- animals appearing in adult/ children’s dreams
- male vs female characters appearing in mens vs women’s dreams

Answer 14

• The dreamer is often an active character rather than a passive observer in their dream, but not the central focus
  — Characters are adults, mostly from our present life
  — Strangers are often present in a role or function, i.e. teacher etc
  — Acquaintances and colleagues are more common than family members
  — Dreaming about prominent people or fictional characters is rarer
• Animals appear in 40% of children’s dreams vs 5% in adult dreams (In pre-industrial and hunter-gatherer societies adult dreams feature animals 5x more than those in urban societies)
• Women’s dreams contain an equal proportion of male and female characters, whereas men’s dreams contain twice as many male characters as female, and this is true cross-culturally and in children

Question 15

Social Interactions in Dreams

Answer 15

• Neutral interactions although they tend to be more negative than in waking life
• Aggressive or friendly interactions are mainly through words and gestures rather than physical contact
• Aggression occurs with those that we clash with during our waking lives
• Interactions that are sexual occur ~12% for men and ~4% for women
  – In women the sexual interaction is with familiar characters more often than in males

Question 16

Sensory Imagery in Dreams
- what are dreams typically
- % of REM and NREM dreams lacking sensory imagery
- what are prevalent
- who don’t dream with visual imagery, what do they have instead?
- visual imagery in those blind after 5-7y
- those deaf report…

Answer 16

• Dreams are typically very vivid and intense, with several sensory aspects, visual, auditory, tactile etc
• 10% of all REM dreams and 30% of NREM dreams lack any sensory imagery – they are just thoughts
• Visual images are prevalent. Sounds are reported in 50% of the time, whereas smells, tastes and pain are reported in less than 1% of the reports
• Those born blind and those that became blind before the age of 4-5y do not dream with visual imagery but include detail on other sensations.
• If blind after 5-7y initially dream with visual imagery but this diminishes over time
• Those deaf report intense visual dreams

Question 17

Bizarreness in Dreams
- occurs in how many actions?
- can also be?
- may include?
the degree of bizarreness varies across… explain

Answer 17

• Bizarreness primarily occurs in actions (43%), such as things that are impossible (flying or walking through walls), or improbable (being hit by a tsunami)
• Can also be subtler i.e. the pen you are holding becomes a spoon
• May include uncertainties, incongruities and scene shifts
• The degree of bizarreness varies across sleep stages with most occurring in REM

— 75% of REM reports contain at least one feature of bizarreness (10-20% contain 3+)
— 60% of NREM dreams contain bizarreness
— 33% of N1 dreams contain bizarreness

Question 18

Bizarreness in Dreams
- dreams vary depending on…
- when do the longest and most vivid, intense dreams take place
- in Wamsley et al 2007…

Answer 18

• Dreams vary depending on circadian time
• Longest and most vivid, intense dreams take place when we wake up late in the morning on a weekend following REM.
• In Wamsley et al 2007, participants were:
  – Awakened participants 4 times during the night to collect dream reports
  – Twice from REM sleep – once early in the night and once late in the night
  – Twice from NREM sleep once early and once late
  – Analyzed three dream features: length, bizarreness and emotionality – all were greater in REM vs NREM and all were greater later in the night vs earlier
• Asked subjects to delay their sleep because they wanted to look at the circadian effect
• He would wake them up at diff points and collect a report about what they were dreaming
• Because they went to bed later they woke up later than their habitual time
  Closer to waking up he got another report

Question 19

Typical Dreams

Answer 19

• Common across people. People report having these at least once – being chased, falling, losing one’s tooth etc
• Griffith Miyaki and Tago, 1958 - first major scientific study of dreams of American and Japanese students:

— Americans reported fewer dreams of fire and of more nudity but there were some common themes in both samples:
- Being attacked or pursued
- Falling
- Trying to do something over and over again
- Teachers, school or studying
- Sexual experiences

Question 20

Based on the 1958 study, Nielsen et al (2003) developed a 55-item Typical Dreams Questionnaire and used it to investigate typical dreams in Canadian students and people with sleep disorders

What are the key findings?

Answer 20

a) Consistency in prevalence of typical dream profiles across time and regions of Canada
b) Stability in the typical dream profiles, over four decades after the initial study in 1958
c) Studies in other countries (Germany and Hong Kong) have revealed remarkable similarities in the rank order of themes

Question 21

Nightmares
- occur in?
- % of adults having a nightmare at least once per month
- % of adults reporting at least one nightmare per year

Answer 21

• Occur in people of all ages with a lifetime prevalence, ~100%
• 10-30% of adults have a nightmare at least once per month
• 85% of adults report at least one nightmare per year

*if once a week may be of clinical importance, ~4% of the population

Question 22

Nightmares
1- what are they?
2- occur usually during?
3- what are bad dreams?
4- trauma-related nightmares?
5- sleep terrors?

Answer 22

1- Highly disturbing dreams that seem to awaken the sleeper
2- Nightmares occur usually during REM in the second half of the night and upon waking from a nightmare, people are quickly orientated, realise that it was a dream, and remember what had happened.
3- Bad dreams are negatively toned dreams that do not awaken the sleeper
4- Trauma-related nightmares – tend to accurately replay elements from the traumatic event (vs idiopathic nightmares where there is no apparent reason)
5- Sleep terrors – a distinct sleep disorder taking place in N3- a person is having a bad dream. They may be disturbed and they are not aware this dream is taking place- they are in their deep phase of sleep.

Question 23

Frequency of Themes in Nightmares and Bad Dreams
(Robert & Zadra, 2014)

Answer 23

Physical aggression is highest % (especially for nightmares), followed by interpersonal contacts, failure or helplessness, health-related concerns and then apprehension/worry.

Question 24

Recurrent Dreams
- what are they?
- % of adults reporting at least one recurrent dream
- % negative, mixed and positive
- % of dreams having the dreamer deal with a challenge or threat
- hostile agents in children vs adults dreams?

Answer 24

• Some dreams tend to re-occur i.e. going to school in our pyjamas, falling teeth, forgotten plane tickets or passports - same theme and content
• 70% of adults report having had at least one recurrent dream during their life
• 75% tend to be negative, 10% mixed and 10% positive
• 60% of recurrent dreams have the dreamer deal with a challenge or threat, that is either psychological or physical.
• In children’s dreams, the hostile agents are usually fictional whereas in adult dreams, they are usually human characters

Question 25

Lucid Dreaming
- what is it?
- how can the experience vary?
- is it difficult to have this lucidity?
- _______ vs ________
- Keith Hearne and Stephen LaBerge:

Answer 25

• Knowing that we dream while in a dream – heightened public interest
• The experience can vary from being pre-lucid (when people question whether they are lucid dreaming or not and then they wake up), to having short-lived lucidity, to being lucid and maintaining mental abilities as if awake
• Having this lucidity is not that difficult, but staying in this mode is tricky
• Lucid dreaming vs lucid control – most prefer to go with the flow and there are still not any documented benefits of this
• Keith Hearne and Stephen LaBerge: recorded from Alan Worsley, a skilled lucid dreamer to signal lucid dreaming by moving his eyes far to the left and then far to the right. His EEG and EMG are at the London Science Museum (1975)
• Stephen LaBerge – Exploring the World of Lucid Dreaming etc

Question 26

What is the function of dreams?
Francis Crick and other theories which have been postulated

Answer 26

Francis Crick: REM sleep likely serves the function of reverse learning, whereby the brain erases memories replayed in the dreams we never remember – “we dream in order to forget” (Crick and Mitchison, 1983, Nature)

Following this publication, several theories have been postulated:
- Dreams have no adaptive or biological function
- Dreams help us solve problems
- Dreams have an evolutionary function
- Dreams play a role in emotional regulation
- Dreams have a memory function

Question 27

Activation-Synthesis Hypothesis Hobson & McCarley (1977)

Answer 27

• Simply a phenomenon which is a consequence of the neurophysiology of REM sleep (bottom-up view on dreams)
• Dreaming is dismissed as unimportant

— The brainstem is activated during REM and sends signals to the cortex which creates images with actions and emotions from memory
— The frontal cortex is less activated during dreaming, so there is no logic in the timing or the sequence of events, although the person tries to organise the content into a logical story when awake
— There is no meaning in dreaming although dreams are based on each person’s experiences (meaningless activation)

Question 28

Maquet et al 1996: The pattern of brain activation during dreaming may explain why dreams are the way they are- HOW

Answer 28

• Activation of the limbic system
• Decreases in activity of the dl PFC (executive functions)
• Activation of the motor cortex

Question 29

Can we read people’s dreams?

Answer 29

• fMRI allows for multivoxel pattern analysis

Horikawa et al., 2013 Science
- Able to match activation of the brain when participants were exposed to certain stimuli with activity in the brain during dreaming. Thus, the pattern of activity could be matched to the content of dream reports
- Potential to objectively study dreams via the neural pattern of brain activity

• However, we know that many of us dream about things or beings that are not based on real/existing stimuli

They could see similar activity patterns in their brains

Question 30

Dreams, Problem Solving and Creativity
1- examples
2- what does dreaming facilitate?
3- examples of dreams leading to solutions

Answer 30

1:
- Mary Shelley – Frankenstein
- Paul McCartney Yesterday
- Tartini – violinist who dreamed of the devil playing a tune on his violin and composed the “The Devil’s Trill Sonata”

2:
- Dreaming facilitates our waking creativity by helping us problem-solve, in a not-so-explicit way

3:
- Some examples of dreams that lead to solutions to a scientific question:
- Dimitri Mendeleyev 1869 had a dream about the periodic table – “I saw a dream, a table, where all the elements fell into place as required. Awakening I immediately wrote it down on a piece of paper” Zadra and Stickgold, 2021, p.177.
- Otto Lowei 1921 dreamed of an experiment (Nobel Prize, 1936)- Acetylcholine

Question 31

Problem Solving and Creativity

Answer 31

• August Kekule, a German chemist in 1865 was struggling to decipher the structure of the chemical benzene which was known to contain 6 carbon atoms, but all atoms behaved the same way, which could not be explained by serial sorts of arrangements. There had to be a different way.
• He had a dream:
  “I was sitting writing at my textbook but the work did not progress… I turned my chair to the fire and dozed…the atoms were gamboling before my eyes…My mental eye, rendered more acute by the repeated visions of this kind, could now distinguish larger structures of manifold conformation: long rows sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke…I spent the rest of the night in working out the consequences of the hypothesis”(Zadra and Stickgold, 2021, p. 178)

Trying different assortments of carbon molecules.

Question 32

Problem Solving and Creativity
Elias Howe and James Watt

Answer 32

Elias Howe – spent years trying to invent the mechanical sewing machine

He had a dream of ‘natives’ throwing spears at him. These spears had holes just below the sharp point at the front and they kept bouncing in and out of the ground.

James Watt - lead pellets for guns
- Lead pieces were not formed into a perfect sphere
- He dreamed on three different occasions that he was caught in a rainstorm of molten lead. He created a tower from which splattered molten lead was dropped. As the drops fell, they assumed a spherical shape and cooled before hitting the floor

Question 33

Problem Solving and Creativity
- when did many of these come from?
- who took advantage of this

Answer 33

Many of these came from the hypnagogic period after thinking about solutions to a problem shortly before sleep

Some have taken advantage of this, like Thomas Edison (Fort Myers, Florida) where he would sit on his armchair with a tin plate on the floor placed on the side of the chair. He would sit on his armchair with a metal spoon on top of the plate.

Hypnagogic period- Period where we go from wakefulness to sleep- NREM1 stage where a lot of dreaming takes place

Question 34

However… (in relation to creative breakthroughs)

Answer 34

Such creative breakthroughs are rare and they tend to happen to those that spend a lot of time working on something

Dormio- - an electronic version of Edison’s technique and records the dreams created by Adam Horowitz at MIT (part of a new wave of dream-engineering technology)

Still not clear what happens with dreams later in the night (like Otto Lowei’s dream). Most of these are not remembered well, and they seem to be quite rare

Question 35

2000 - Finnish philosopher and cognitive neuroscientist Antii Revonsuo proposed an evolutionary model of dreaming- EXPLAIN

Answer 35

• Dreaming evolved as a mechanism for simulating threatening events and rehearsing possible means of avoiding or surviving them
• Known as “threat simulating theory” (TST)- testing different solutions to threats whilst we are dreaming
• Empirical evidence has been mixed – only a small percentage of dreams with threats contain effective avoidance responses
• Closer examination of such dreams revealed that 80% of those dreams were fictional and the threats were unlikely to occur in waking life

Question 36

Dreaming is adaptive
- what did Valli and Revonsuo (2009) argue?
- hypothesis?

Answer 36

• Valli and Revonsuo (2009) – argued that dreams are biologically adaptive and they lead to enhanced coping strategies

— Coping Hypothesis (also known as ClinicoAnatomical Hypothesis) (top-down view on dreams) :

• People dream about events in their lives that they find threatening
• Problem-solving occurs during sleep (“sleep on it”)

Question 37

Emotional Regulation: Nighttime Therapy

Answer 37

• Ernest Hartmann (Tufts U) worked with trauma victims
• Proposed that dreaming is a form of nighttime therapy that helps integrate emotional concerns and even traumatic events into existing memory systems (all within the safety of sleep)
• Dreams create connections between new and old memories that are broader and looser than connections made during wakefulness

Question 38

Rosalind Cartwright

Answer 38

• Emotion-regulating function of dreaming in her studies of recently divorced men and women
• Dreaming or at least REM sleep dreaming, plays a role in regulating negative emotions
• Could it be that sometimes dreams help us solve problems and other times they provide a unique environment in which to rehearse social interactions, learn to avoid threatening situations or process emotions?

Question 39

Dreams and Emotional Regulation
- consistent across?
- Cartwright, 1979: Three phases in the dreams of a single night- list these
- the result is…
- when stress is too high or too low…

Answer 39

• Consistent across decades (Domhoff, 1996)
• Cartwright, 1979: Three phases in the dreams of a single night
  – 1st REM period - sets the theme on an emotional level
  – 2 & 3rd periods - past experiences related to that theme are brought up
  – 4 and 5th REM Periods – the theme is extended into possibilities for the future
• The result is the progression which is beneficial to the dreamer.
• When stress is too high or too low, there is very little progress

More distress in beginning of night compared to end of night- emotional stress -> dealing with emotions

Question 40

Memory function- what experiment and explain

Answer 40

• Tetris experiment Stickgold et al (2000) showed that the participants were clearly dreaming about the game at sleep onset, reporting unambiguous descriptions of the game:

“Tetris shapes floating around in my head like they would in the game, falling down, sort of putting them together in my mind”

• Interestingly, patients with amnesia (damage to the hippocampus) had no recollection of playing the game even though they played for 7h over 3 days-they but also had dreams of blocks turned on their side
• Known as the “Tetris Effect”

Spending a lot of time playing tetris -> when going to sleep they ‘continue playing it’- by processing what we experienced during wakefulness (seeing blocks in sleep)

Question 41

Abstract exploration?
Wamsley et al 2007

Answer 41

Study on virtual maze where participants explored it and then took a 90m-nap.
- After their nap they were asked whether they dreamed about the task and then they were tested in the maze
– Those who reported not dreaming about the task took longer to find their way out

• Repeated the experiment but this time waking them up during their naps and asked about any dreams
  – Those who reported dreaming of the task showed 10x more improvement after their naps compared to those who reported unrelated dreams

“I was thinking about the maze and kinda having people at checkpoints, I guess and then that led me to think about when I went on this trip a few years ago and we went to see these bat caves and they’re like, maze-like”

Question 42

So what do dreams do then?

Answer 42

• Dreams create narratives that unfold in our minds and allow us to experience thoughts, sensations and emotions
• Narratives allow the brain to imagine and explore possibilities, the ‘what ifs’
• Proposed as the NEXTUP model by Antonio Zandra and Robert Stickgold, 2021

Question 43

Semantic Priming and Dreaming
James Neely, Yale U.

Answer 43

• Evidence that during REM sleep, the brain preferentially strengthens weak associations (Stickgold et al., 1999)
• Series of words and non-words were presented, and participants responded by pressing a key labelled “word” or “non-word” and measured speed and accuracy

– Before the targets were displayed, another word was flashed on the screen for a few ms – the “prime”.
– The relationship between the prime and the word affected the speed and accuracy of the response i.e. target word “wrong” leads to a faster response when the prime preceded was the word “right” than when it was preceded by the word “thief”, but still faster in both, compared to an unrelated prime such as “prune”

• During the day, strong primes (right/ wrong) resulted in 3x faster responses compared to weak primes (wrong/ thief)– Priming effect
  – Testing in just 2-3 min upon waking also yielded the same findings

Priming- prepares our brain, may respond faster to stimuli with is relevant
Either saw a related or non-related word
They responded faster to related word

Question 44

Semantic priming and Dreaming

Answer 44

But there was a different outcome when testing was done in the middle of the night after waking them from REM sleep:
- priming produced by strongly associated words dropped by 90% while priming produced by weak primes increased more than two-fold
- their brains were activating weakly related words (ie. “theif”) 8x more effectively than strongly related words (ie “right”)

When we dream, weak associations are tried out

• NEXTUP predicts that weak associations are explored to understand possibilities, supported by changes in neurochemistry
  – close concept to divergent or creative thinking, free-flowing thinking to generate a number of insights and potential answers to an initial question
  – dreams allow us to explore network connections to understand possibilities (synthesis of information rather than rote memory of learning)

Question 45

NEXTUP

Answer 45

“Proposes that dreaming is a unique form of sleep-dependent memory processing, that extracts new knowledge from existing memories through the discovery and strengthening of previously unexplored weak associations”, pg 108, When Brains Dream 2021

• During dreaming we search and strengthen novel, creative, insightful and useful associations

Question 46

The function of NEXTUP by stage

Answer 46

Hypnagogia (N1) “What ongoing concerns was I just thinking about?” →
N2 Dreams: “What associated recent memories can I find?” →
REM Dreams: “What remote, weak associations can I find?”