Sleep and Dreaming

REM sleep

a part of the sleep cycle with rapid eye movements caused by eyes moving a lot behind the eyelids when dreaming occurs

Sleep cycle

a nightly pattern of deep sleep, light sleep and dreaming

NREM sleep

non-rapid eye movement sleep (rapid eye movement does not occur)

Sensory blockade

In REM sleep, all incoming sensory information is stopped.

Neuron

A nerve cell that transmits information

Movement inhibition

In REM sleep, when movement is prevented

Stage 1 (sleep onset)

Theta waves- light sleep and you easily wake up during this stage. Muscles are less active, eye movements slow and you can twitch suddenly.

Stage 2 (late night stage)

Theta waves and bursts of activity (spindle)- your brain waves are slow, eye movement stops, temperature drops, heart rate slows.

Stage 3 ( Deep sleep)

Slow delta waves (20%-50% of the time)- but also some faster waves. Transition between light and deep sleep.

Stage 4 ( deep sleep)

Slow delta waves (more than 50% of the time)- very deep sleep, hard to wake up, no eye movement, disorientation if woke up. Sleepwalking & night terrors occur.

REM sleep

Difficult to awaken, associated with vivid dreams. High level of mixed wave activity. Muscles are virtually paralyzed.

Facts (AO1) about REM sleep

• Rapid eye movements, flickering eyelids

• Dreaming occurs (we dream for about 2 hours per night)

• Sensory blockade- no sensory input received (all senses blocked)

• Movement Inhibition- The pons shuts off spinal cord neurons, preventing movement

• Irregular breathing, increased heart rate and blood pressure.

The sleep cycle

• Lasts 90 mintues

• As cycle progresses, REM sleep loinger and there is less deep sleep.

• Towards morning we are mostly in stages 1 and 2 and REM sleep.

Functions and benefits of sleep (1)

• Adults need 7-8 hours of sleep, teenagers need around 9

• 65+, deep sleep stop, possible due to age or medication

• If people sleep during the day or immediately when they go to bed, this suggests that they are sleep deprived.

• Sleep deprivation means that a person will not function as well at a high level, which may affect weight and brain functioning.

• Animal studies suggest that sleep=survival

Functions and benefits of sleep (2)

• 20% of our sleep is REM sleep.

• For infants= 50%

• REM sleep stimulates learning+increase of protein

• Dement and Kleitman (1957)- found that people tended to report dreaming when woken up in REM sleep-dreaming takes place during REM sleep

• Other have reported dreaming during NREM sleep, so cannot draw definitve conclusions.

Endogenoous

internal pacemakers/ our biological clock

Hormones

chemical messengers taking messages through the bloodstream

Melatonin

a hormone involved in setting a circadian rhythms, including the sleep-wake cycle and blood pressure.

Pineal gland

a small gland that produces a hormone that is secreted into the bloodstream

Exogenous

external cues in the environment that affect our biological clock

Zeitgebers

external cues that synchronize our biological rhythms

Circadian rhythms (1/2)

• Circadian= 24 hour cycle

• The Suprachaismatic Nucleus (SCN)

• SCN set by triggers e.g. light

• during circadian rhythms- body temp changes and hormonal changes

Circadian rhythms- how does it affect our body temp and the sleep-wake cycle

• body temp-rises-end of sleep

• body temp-drops-ready to sleep

• Jet-lag: affects sleep-wake cycle. Sleep- wake cycle affected by time cues. Different time zones have different light and time cues (sunset is different)

• Shift work- affects sleep-wake cycle. You work at odd times like through the night. These different time and light cues affect your sleep-wake cycle.

Ultradian Rhythms

• rhythms that occur in a period of less then 24 hours.

• Sleep cycle consists of about 5 cycles of 90 minutes periods of different stages of sleep.

• Heart rate, blood circulation and appetite are also ultradian bodily rhythms.

Internal influences on sleep- hormones

• The SCN is affected by internal and external influences.

• Sleep helps to reset hormones and what we do affects our hormone level. Hormones send chemical messages around the body using the blood stream.

• Hormones can affect sleep because of stress

• Stress- the ACTH hormones releases cortisol- cause alertness and effects sleep.

• Research= insomnia people- higher ACTH level than those who sleep normally.

Internal influences - pineal gland and melatonin

• Melatonin is triggered by darkness- helps regulate circadian rhythms

• Melatonin helps with - insomnia treatment, adjusting to jet lag.

• Pineal gland regulates sleep-wake cycles.

Strengths of internal influences on sleep

• Hamster study (SCN removal)- when SCN removed, biological rhythms stopped. When SCN was transplanted back, sleep cycle returned.

• Blind person (Miles et al.) - found circadain rhythm was closer to 25 hours.

• Melatonin study (Li-you Chen et al,2015) - sleep deprivation in rats reduced melatonin levels, proving melatonin’s role in sleep.

Weaknessess of internal influences of sleep

• Animal studies- hard to generalize findings to humans.

• Blindness Study limilation- not all blind people have the same experience (some can dectect light)

External influences

• external influences= environmental features

• includes stress, what we eat and drink, medication.

external influences on sleep

• Zeitgebers- time givers

• Includes light-dark cycle and the 12 month cycle of seasons.

• Duffy & Czeisler (2009)- Entrainment- when biological rhythms are matched to their environmental triggers such as circadian rhythms being set in response to external cues.

Primary sleep disorders

The disorder itself is the main problem (insomnia)

Secondary sleep disorders

Sleep problems are caused by another condition (depression)

Insomnia

Difficulty sleeping at night, leading to problems during the day

Acute insomnia

Short-term sleep problems

Chronic insomnia

Sleep issues occuring 3+ nights per week for at least 3 months

Symptoms of Insomnia

• Trouble falling asleep

• Waking up frequently during the night

• Lying awake for long periods

• Not feeling rested after sleep

• Daytime tiredness and difficulty sleeping even when exhausted

• Irritability and difficulty concentrating.

Causes of Insomnia

1) Lifestyle factors- jet lag, shift work disrupt bodily rhythms

2) health conditions- mental/physical illenesses

3) Medication, Food and drink

• caffeine, diet pills, and smoking- disrupt sleep

• Alcohol- keeps people in light sleep, making them wake up easily

• antidepressants- supports REM sleep

Narcolepsy

A neurological disorder causing uncontrollable daytime sleep episodes

Symptoms of Narcolepsy

• Excessive Daytime sleepiness (EDS)

• Hallucinations & vivid dreams

• Cataplexy (70% of cases)

• Sleep paralysis & abnormal REM sleep

Causes of Narcolepsy

• Genetic Factors- family history of narcolepsy

• Neurotransmitter imbalance- low levels of hyprcretin a neurotransmitter regulating wakefulness

Importance of the unconcious

• unconcious mind- hidden part of the mind that influences behaviour

• Dreams are symbols of unconcious thoughts

• Psychoanalysts analyze dreams to uncover hidden meanings

• the unconscious mind stores repressed thoughts

Id?

‘ i want’ (instincts & desires)

Superego

‘you can’t have’ (moral conscience)

Ego

Balances the id and the superego (reality principle)

Manifest Content

The dream’s story

Lantent Content

The hidden meaning behind the dream

Lost in woods/maze

feelings emotionally lost or stressed

Car problems

Lack of control in life

Being chased

avoiding a difficult emotion

Dreamwork

the transformation of unconcious thoughts into dream content

condensation

1. Multiple ideas combine into one.

   • (e.g., Feeling ugly, fat, and lonely → Dreaming of a hippo).

Displacement

1. Unimportant details seem important.

   • (e.g., Dreaming about bees, but the real issue is tripping over).

Secondary elaboration

1. The mind adds details to make a dream make sense.

   • (e.g., Dreaming of falling, then driving → The brain adds a parachute to connect events).

 

Strengths of Freud’s Dream theory

✅ Qualitative Data → Detailed, real-life cases increase validity.
✅ Recognized the power of the unconscious → Provided a way to study it.
✅ Supporting evidence → Guenole et al. (2013) found that dreams help "guard" sleep.

Weaknesses of freud’s dream theory

❌ Cannot be scientifically tested → Dreams cannot be proven true or false.
❌ Unscientific → No objective way to measure dreams.
❌ Not generalizable → Based on case studies (e.g., Little Hans), so results don’t apply to everyone.

Aim of little hans

To describe the course of an illness and the subsequent recovery of a five-year-old boy.

Procedure

His parents logged Little Hans's development since age 3. Freud, meeting Hans a few times, studied him, aware of being observed. Three focus areas: studying dreams, analyzing Hans's statements, and examining his phobia of horses through psychoanalysis.

Findings of Little Hans

• Phobia of horses

  • hans phobia of horses- links it to when a horse fell and died infront of him.

  • horse is hans’s father, black bits around the mouth represents father’s moustache- supports Odeipus complex.

• Early dreams

  • hans dreamt of no mother- caused anxiety- unconscious desire for his mother

• Giraffe Dream- dream featuring giraffe shouting at hans for taking away a crumple giraffe.

Conclusion of Little Hans

The findings support Freud’s theory, particularly the Oedipus complex during the phallic stages.

Strengths of Little Hans

Validity: Qualitative data offers rich detail, enhancing result validity.

Real-world application: Findings can be applied, for example, in psychoanalysis to treat phobias.

Weaknesses

Generalizability: Being a case study, results may not represent the wider population.

Validity: Interpretation by Freud and Hans's father introduces potential bias, reducing result validity.

Ethics: Little Hans may have experienced psychological harm in discussing his phobias.

Activation synthesis theory

The brain randomly activates neurons, and the mind tries to create a story from them.

Key features of the activation synthesis theory

• Movement inhibition

• Sensory blockade- Brain is working with internal signals rather than real world stimuli

• Random activation- Neurochemicals cross synapses, sending messages → creates random thoughts.

• Synthesis- The brain tries to make sense of the random signals by creating a story.

Strengths- Activation synthesis theory

• Scientific evidence

  • REM sleep = muscle paralysis + no sensory input,

    supporting the idea that the brain is creating dreams internally.

• High reliability

  • Use of brain scans, which is an objective measure

Aims of Siffre

1. To investigate how the body clock works without external time cues (zeitgebers).

2. To see if his natural body cycle would change (24 vs. 48 hours).

3. To apply findings to astronauts in space.

Procedure- Siffre

• Location: Midnight Cave, Texas, USA.

• Time: 6 months with no natural daylight or time cues.

• Tasks:

  • Conducted blood pressure tests, memory tests, and physical tests.

  • Practiced shooting accuracy.

  • Wrote in a diary to record his thoughts and experiences.

• Daily Routine:

  • Woke up → Called the team → They turned on the lights.

  • Did daily tests and activities.

  • When sleepy → Called the team → They turned off the lights.

(Results) Psychological effects- Siffre

• Desperate for companionship

• Record player and books got ruined- Suicidal thoughts

• STM declined- Similar to astronauts in space

(Results) Circadian rhythm effects- Siffre

• Sleep-wake cycles varied unpredictably between 24 to 52 hours.

• His body clock did not stay consistent (was neither 24 nor 48 hours).

(Results) Physical effects

• Eyesight worsened.

• Psychological health deteriorated.

Conclusion- Siffre

1. Circadian Rhythms are not fixed → His sleep-wake cycle varied significantly without time cues.

2. Astronauts may experience body clock changes but can adapt to new cycles.

3. Social isolation is the biggest problem → Lack of interaction can lead to severe psychological effects (e.g., suicidal thoughts).

Strengths- Siffre

• Use of Qualitative data

  • This is rich in detail & depth

• Longitudinal study

  • A lot of information was gathered regarding the sleep-wake cycle

Weaknesses- Siffre

• Case study- Not generalisable

• Use of Artificial Light- Can influence body clock- external cue