Sleeping and Dreaming

Dreaming

Happens any time during sleep, but the ones you'll remember happen in REM sleep

Regeneration

During sleep, your body regenerates energy, tissues, cells and muscles

Repair

During sleep, your body repairs damaged tissues and cells

Detox

Circadian Rhythm

Internal body clock, regular bodily rhythms that occur on a 24-hour cycle

Endogenous

Internal pacemaker: circadian rhythm

Exogenous

External factors affecting sleep, such as light and time cues, food input, medication, environment

Internal factors of sleep

• Suprachiasmatic nuclei (SCN)

• Hormones

• Melatonin

Suprachiasmatic nucleus (SCN)

Involved in maintaining and synchronising the circadian rhythm and ultradian rhythms, set by external triggers

Hormones

Triggered by darkness, can be found in medication that helps with insomnia and jet lag but may not work on shift workers

Melatonin

Produced when in the dark, helps time circadian rhythms and sleep, when exposed to light at night, production of melatonin is prevented. Produced in the pineal gland.

Pineal Gland

Produces melatonin, maintains circadian rhythm

External factors of sleep

• Environmental stress

• Diet

• Medication

• Zeitgebers

Zeitgeber (Time givers)

Factors outside the organism, such as light exposure, season, food, social interaction, music.

Zeitgeber: Light

Light is the most important zeitgeber, the cells sensitive to light in the retina of the eye lets the internal body clock know if it's day or night, can prevent us from sleeping

Insomnia

Difficulty in falling asleep or staying asleep

Sleep-onset insomnia

Needing at least 30 minutes to fall asleep on average

Sleep-maintenance insomnia

Waking up during the night and staying awake for at least 30 minutes, unable to fall asleep again

Insomnia: Prevalence

One in 3 people, often found in senior citizens

Insomnia: Symptoms

• Difficulty with falling asleep

• Waking up a lot during the night

• Frequently lying awake during the night

• Not feeling refreshed on waking

• Finding it hard to fall asleep in the day when tired

• Feeling irritable and unable to concentrate

Chronic Insomnia

When insomnia happens more than 3 times a week and lasts for 3 months

Insomnia: Causes

• Flying a lot and jet lag that will affect internal body clock

• Mental or physical issues

• Medication, food and drink, influenced by different neurotransmitters and hormones

Sleep Cycle

Progression of sleep stages, takes around 90 - 110 minutes

Sleep Cycle: Stage 1

• Light sleep

• Can be easily woken up

• Muscles are less active

• Slow eye movements

• Sends alpha and theta waves

Sleep Cycle: Stage 2

• Late night stage

• Slower brain waves

• More theta waves

• No eye movements

• Bursts of brain activity (called spindles)

• Body temperature starts to drop and heart rate slows

Sleep Cycle: Stage 3

• Deep sleep

• No eye movements

• Slow delta brainwaves, but there are still fast waves

Sleep Cycle: Stage 4

• Deep sleep

• Mainly slow delta waves

• Hard to be woken up

• No eye movements

• If woken up, people will feel disoriented

• Children can experience sleepwalking or nightmares

Alpha brain waves

Brain-wave pattern associated with relaxed wakefulness and drowsiness.

Theta brain waves

Low frequency, medium amplitude brain waves experienced during sleep

Delta brain waves

Deepest sleep, lowest frequency & highest amplitude.

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at random times.

Narcolepsy: Prevalence

One in every 2000 people, occurs equally in

Narcolepsy: Symptoms

• Excessive daytime sleepless (EDS), they can fall into sleep any time in daytime

• Hallucinations and vivid dreams

• Cataplexy = loss of muscle power

• Sleep paralysis and abnormal REM sleep

Narcolepsy Causes

Siffre's study (1975)

Activation Synthesis Theory (Hobson and McCarley, 1977)

Theory that dreams are formed of random thoughts but made sense

Sensory blockade

During REM sleep, no sensory information (sight, sound, taste, touch, smell) enters the brain

Movement Inhibiton

Where the body is unable to move due to paralysed muscles

Random Activation

During REM sleep, random neurons are being fired instead of deliberately

[Activation] Synthesis

When neurons are sending random thoughts to the brain instead of sensory information

Activation [Synthesis]

When the brain is trying to make sense

Freud's theory of dreaming (1900)

Dreams represent unconscious desires and wishes

Unconscious Mind

Freud's term for the part of our mind that we cannot become aware of

Id

Unconscious wishes and desires, the part of the theory that is demanding for your desires to come true

"I want"

Superego

The moral conscience built around guidance and rules, the part of the theory that prevents you from fulfilling your wishes

"You can't"

Ego

Decisions that balance the Id and Superego's demands, one way of doing so is repression

Repression

Defence mechanism by which anxiety-provoking thoughts and feelings are forced to the unconscious and are forgotten

Manifest content

The storyline of a dream that the dreamer remembers

Latent content

The deeper meaning of the dream that is hidden behind the manifest content

Dreamwork

Refers to how the unconscious transforms desires (latent content), hiding them behind the manifest content as a way of censorship of the real desire

Condensation

Many dream-elements (themes, images, figures, ideas etc) are combined or refined into one thing

Displacement

Replaces latent content with a well-hidden element, so the emphasis of the desire is turned into something less obvious to protect the dreamer

Secondary elaboration

Alters dreams and fills gaps to make them less distorted and more vague