Sleep and Dreaming

To sleep is to reinvigorate yourself. Vital functions are carried out when you sleep, and your brain embeds a lot of the information you have learned throughout the day. Dreams are a chaotic, sometimes fun, sometimes terrifying byproduct of sleep that psychologists have investigated for some time, including famous names like Freud. Sleep and dreaming naturally come hand in hand, and we need to know the different functions, stages, and disorders of sleep.

• First, we will explore the sleep and dreaming meaning.
• We will delve into the world of sleep and dreaming, covering the functions and different stages of sleep and dreams, the internal and external influences on sleep, and the functions and actions of the brain during sleep.
• We will explore the various sleep disorders and how to improve sleep, alongside examining dreaming.
• We will provide various facts about dreams and sleep in psychology, briefly highlighting sleep paralysis and dreaming.

Sleep and dreaming often go hand-in-hand; people sleeping vector created by storyset - www.freepik.com.

Sleep and Dreaming Meaning

Sleep is one of the most fundamental aspects of life. We can define sleep, according to the American Psychological Association (APA)¹ as:

We define dreams as¹:

Sleep and Dreams Psychology: Functions of Sleep

The functions of sleep have been highly discussed and researched by psychologists and medical researchers alike. We spend 230,000 hours, or around 26 years, sleeping in our lifetime. Surely something that takes up that amount of time must be important, right?

What we can say about sleep is that sleep aids brain development. Sleep helps our mental health, physical well-being and health, including supporting our immune systems and weight management in addition to our cognitive functioning, such as language, speech, and memory. Sleep releases growth hormones for bodily repair after a hard day's work, and memories are consolidated so you can remember all of the information you learn during the day.

When we are low on sleep, our cognitive and physical functions decline quite heavily:

• We're grumpy, tired, and irritable
• We struggle to remember things
• We struggle to plan things
• We struggle to use language and speech effectively, amongst other declining cognitive functions.

Full sleep deprivation can result in death, although we still don't know how long people can go without sleep before this occurs.

Although it may seem not much is happening during sleep, it is an important and hard-working function that keeps the brain and body in good shape.

Different Stages of Sleep and Dreams

There are four stages of sleep and REM sleep, although there is some debate on whether there is a proper distinction between the third and fourth stages of sleep. All stages go through around five cycles, each lasting approximately 90 minutes.

1. Stage One: we can define stage one as a period of drowsiness, and we can be woken up fairly quickly. Stage one is where we 'fall asleep', characterised by alpha and theta brain waves on an electroencephalogram (EEG).
2. Stage Two: we can define stage two as a period of light sleep. Theta waves still predominantly dominate this stage of sleep but are interrupted by sleep spindles, or bursts of activity, and K-complexes. Body temperature begins to drop here.
3. Stage Three and Four: both stages three and four are characterised by deep sleep, low frequency, high amplitude delta waves, and it is hard to wake someone up in these stages. Heart and breathing rate slow down, and body temperature drops. During deep sleep, the body releases growth hormones.
4. REM Sleep: Rapid Eye Movement (REM) sleep is where the eyes flicker and move quite quickly beneath the eyelid. During REM sleep, dreams are vivid and memorable, and sensory blockade and movement inhibition occur. Neurotransmitter levels balance here.

Brain wave activity changes in different stages of sleep²

Internal and External Influences on Sleep

Bodily rhythms are where we can see the influences on sleep. The sleep-wake cycle is an example of a circadian rhythm, which occurs once every 24 hours. The sleep cycle of four stages and REM sleep, which we discussed above, is an example of ultradian rhythm, which happens more than once in 24 hours.

Internal influences on sleep are known as endogenous pacemakers, and external influences on sleep are known as exogenous zeitgebers.

Siffre Cave Study

Siffre (1975) spent six months in a cave investigating bodily rhythms and how they proceed when in the absence of natural external cues (exogenous zeitgebers). NASA was invested in this study as they wanted to understand how this would impact astronauts undergoing space travel.

Siffre found that his emotional state declined; he felt lonely and started to entertain thoughts of suicide. Siffre's health was also impacted; his eyesight worsened, and his memory suffered. His sleep-wake cycle changed from the usual 24 hours to between 18 and 52 hours.

When exogenous zeitgebers are no longer able to provide external cues to the body to sleep, the circadian rhythm struggles to keep up, although it was possible to some extent.

Sleep Disorders

Sleep disorders include insomnia and narcolepsy.

Insomnia symptoms include:

• Inability to fall and stay asleep
• Waking up frequently
• Feelings of exhaustion from lack of sleep
• Difficulty with napping despite lack of sleep
• Irritability and declining cognitive function

Narcolepsy symptoms include:

• Excessive Daytime Sleepiness (EDS)
• Cataplexy (loss of muscle control/tone)
• Hallucinations

Insomnia can be explained or affected by lifestyle choices, health conditions, sleep hygiene, food, drinks, or medications. Narcolepsy can be explained or affected by low levels of hypocretin (orexin), a neuropeptide that regulates wakefulness, genetic heritability, and stress. Some suggest an evolutionary advantage to narcolepsy by highlighting the usefulness of muscle tone loss in survival situations.

Improving Sleep

We can improve sleep by focusing on improving our sleep hygiene habits. Sleep hygiene includes:

• Creating a relaxed, dark, and comfortable environment to sleep in
• Removing sources of light and noise that can interrupt sleep or cause issues with the sleep-wake cycle
• Exercise regularly
• Meditate and reduce worrying before sleeping (therapy, if stress and trauma are affecting sleep, is an option)
• Reducing caffeine and alcohol intake

Treatment for insomnia and narcolepsy includes improving sleep hygiene.

Facts About Dreaming

As we defined above, dreaming is a state of unconsciousness characterised by fantastical, nonsensical experiences. There are multiple theories on dreaming, with two fundamental ideas taking centre stage:

1. The Freudian Theory of Dreaming
2. The Activation Synthesis Theory of Dreaming

The Freudian Theory of Dreaming

Freud's theory of dreaming centres around his ideas on the conscious and unconscious mind and how the three factors of our personality (the Id, ego, and superego) interact and suppress one another. The unconscious mind is where our, often secret, desires lie.

Dreaming, according to Freud, is seen as a means to fulfil a person's unconscious desires - wish fulfilment - as the ego, the reality principle suppresses the more primitive urges of the Id, is weakened. The weakened state of the ego allows the unconscious desires to seep through, and our dreams are our desires realised in unconscious form.

Freud described dreams through latent and manifest content:

• Latent content is the actual meaning of the dreams, often disguised by the manifest content
• The manifest content is what we see in our dreams and is a symbolisation of the latent content

However, our desires are sometimes disturbing, so to protect the mind from being bombarded by primitive urges, dreamwork hides the content of our dreams through condensation, displacement, and secondary elaboration.

The Wolfman study is a case that supports Freud's theories. However, many do not consider the Wolfman study to be sufficient evidence. The "wolfman" himself described Freud's views on his dreams as outlandish.

Freud's Wolfman study supported that unconscious, hidden messages manifest in our dreams, vector created by inventorsolutions - www.freepik.com.

The Activation Synthesis Theory of Dreaming

The activation-synthesis theory of dreaming takes a more biological approach to explain why we dream.

According to the activation-synthesis theory of dreaming, dreams are a byproduct of brain activation that occurs when we sleep. It is our mind's way of trying to make sense of these activations and combine them into understandable dreams.

The mind synthesises dreams during the activation of specific regions of the brain during REM sleep, and these areas are often involved in:

• The processing of emotions
• Sensations
• Memories

The activation-synthesis theory can also explain why dreams can be illogical, only make sense to the dreamer, and often are lost when they wake up.