Psychology. Tutorial
4. Consciousness and its Variations
1. The concept of consciousness.
2. Theories of sleep: repair theory, ecological theory, information consolidation theory.
3. Stages of sleep.
4. Sleep disorders. Dreams. Theories of dreams interpretation.
1. Consciousness.
Along with the development of sciences, especially history, philosophy, biology, the views on human origin and consciousness formed gradually.
The most important precondition for the emergence of human consciousness was a peculiar life conditions complication, in which anthropoid creatures lived. Under the influence of life conditions (social way of life, labor, climate) their central nervous system became more complicated structurally and functionally. In the cerebral hemispheres parietal, temporal and especially frontal lobes developed gradually that improved adaptive functions of organism. These lobes were developed extremely noticeably under the labor influence. So in the process of biological development appeared the preconditions for the origin of the higher specifically human psyche form – consciousness.
During historical development in different specifically human activity types, consciously directed cognitive activity, imagination, human senses and will qualities, various psychic properties, which essentially differ from instinctive psychic animal activity were formed gradually.
Labor, social way of life are the basic preconditions for historical development of human consciousness as the higher psyche form, in which reveals human attitude towards the environment, ability to change the nature and to fit it to one's needs become obvious. These psyche peculiarities are not typical of animals. They do not discern themselves from the environment, adjust to it passively.
The consciousness is the highest period of psychic development and the product of the social and historical development.
Consciousness is awareness of both external and internal stimuli or events. The external events include what you attend to as you go through your day – the comment your best friend just made about your hairstyle, the car in front of you that just swerved to miss a dog, the music you are listening to on your Walkman, for example. Internal events include your awareness of sensations, thoughts and feelings – headache just returned, too fast breathing, stomach's rumbling, and anxiousness about the exam.
The contents of our awareness may change from one moment to the next, since information can move rapidly in and out of consciousness. Many years ago, William James (1890) described the mind as a stream of consciousness – a continuous flow of changing sensations, images, thoughts, and feelings. Our minds race from one topic to the next – from thinking about the person who is approaching us, to how well we feel, to what we are going to do tomorrow.
While William James was interested in charting the shifting nature of our stream of consciousness, Sigmund Freud (1900-1953) believed that most of our thoughts are unconscious. Unconscious thought, according to Freud, is a reservoir of unacceptable wishes, feelings, and thoughts that are beyond conscious awareness. Unconscious thought has nothing to do with being unconscious after being knocked out by a blow on the head in a boxing match, being anesthetized, or falling into coma.
According to Freud, unconscious thoughts are too laden with sexual and aggressive meaning for consciousness to admit them. Freud believed that one of the psychotherapy's main goals was to bring unconscious thoughts into conscious awareness so they can be addressed and dealt with.
Freud accurately recognized the complexity of consciousness. It is not simply a matter of being aware or unaware. Consciousness comes in different forms and levels. Sometimes consciousness is highly focused and alert (controlled processes, focus attention required), at other times it is more passive (automatic processes, minimal attention required).
Daydreaming is another form of consciousness that involves a low level of conscious effort. An altered state of consciousness occurs when a person is in a mental state that noticeably differs from normal awareness. Drugs, meditation, traumas, fatigue, hypnosis, and sensory deprivation produce altered states of consciousness.
2. Theories of sleep.
There are three main theories about why we sleep – repair theory, ecological theory and information consolidation theory. Repair theory states that sleep restores, replenishes, and rebuilds our brains and bodies, which somehow are worn out or used up by the day's waking activities. This idea fits with the feeling of being "worn out" before we sleep and "restored" when we wake. Aristotle proposed a repair theory of sleep centuries ago, and most experts today believe in some version of repair.
This theory also suggests that NREM sleep is important for restoring physiological functions, while REM sleep is essential in restoring mental functions.
Support for this theory is provided by research that shows periods of REM sleep increase following periods of sleep deprivation and strenuous physical activity. During sleep, the body also increases its rate of cell division and protein synthesis, further suggesting that repair and restoration occurs during sleeping periods.
Ecological theory is a relatively recent view of why we sleep. This evolutionary-based approach argues that the main purpose of sleep is to prevent animals from wasting their energy and harming themselves during those parts of the day or night to which they have not adapted. For example, it was not adaptive for our ancestors to fumble around in the dark, risking accidents or attack by large predators such as lions or bears. So, like the chimpanzees who slept safely in treetops, our ancestors presumably hid and slept through the night.
So, according to this theory, all species have adapted to sleep during periods of time when wakefulness would be the most hazardous.
Support for this theory comes from comparative research of different animal species. Animals that have few natural predators, such as bears and lions, often sleep between 12 to 15 hours each day. On the other hand, animals that have many natural predators have only short periods of sleep, usually getting no more than 4 or 5 hours of sleep each day.
Information consolidation theory. The information consolidation theory of sleep is based on cognitive research and suggests that people sleep in order to process information that has been acquired during the day. In addition to processing information from the day prior, this theory also argues that sleep allows the brain to prepare for the day to come. Some research also suggests that sleep helps cement the things we have learned during the day into long-term memory. Support for this idea stems from a number of sleep deprivation studied demonstrating that a lack of sleep has a serious impact on the ability to recall and remember information.
While there is research and evidence to support each of these theories of sleep, there is still no clear-cut support for any one theory. It is also possible that each of these theories can be used to explain why we sleep. Sleeping impacts many physiological processes, so it is very possible that sleep occurs for many reasons and purposes.
3. Stages of sleep.
The invention of the electroencephalograph led to some major breakthroughs in understanding sleep by revealing how the brain's electrical activity changes during sleep.
The Beginnings of Sleep
During the earliest phases of sleep, you are still relatively awake and alert. The brain produces what are known as beta waves, which are small and fast. As the brain begins to relax and slow down, slower waves known as alpha waves are produced. During this time when you are not quite asleep, you may experience strange and extremely vivid sensations known as hypnagogic hallucinations. Common examples of this phenomenon include feeling like you are falling or hearing someone call your name.
Another very common event during this period is known as a myoclonic jerk. If you've ever startled suddenly for seemingly no reason at all, then you have experienced this odd phenomenon. While it may seem unusual, these myoclonic jerks are actually quite common.
Stage 1
Stage 1 is the beginning of the sleep cycle, and is a relatively light stage of sleep. Stage 1 can be considered a transition period between wakefulness and sleep. In Stage 1, the brain produces high amplitude theta waves, which are very slow brain waves. This period of sleep lasts only a brief time (around 5-10 minutes). If you awaken someone during this stage, they might report that they weren't really asleep.
Stage 2
Stage 2 is the second stage of sleep and lasts for approximately 20 minutes. The brain begins to produce bursts of rapid, rhythmic brain wave activity known as sleep spindles. Body temperature starts to decrease and heart rate begins to slow.
Stage 3
Deep, slow brain waves known as delta waves begin to emerge during stage 3 sleep. Stage 3 is a transitional period between light sleep and a very deep sleep.
Stage 4
Stage 4 is sometimes referred to as delta sleep because of the slow brain waves known as delta waves that occur during this time. Stage 4 is a deep sleep that lasts for approximately 30 minutes. Bed-wetting and sleepwalking are most likely to occur at the end of stage 4 sleep.
Stage 5
Most dreaming occurs during the fifth stage of sleep, known as rapid eye movement (REM) sleep. REM sleep is characterized by eye movement, increased respiration rate and increased brain activity. REM sleep is also referred to as paradoxical sleep because while the brain and other body systems become more active, muscles become more relaxed. Dreaming occurs due because of increased brain activity, but voluntary muscles become paralyzed.
The Sequence of Sleep Stages
It is important to realize, however, that sleep does not progress through these stages in sequence. Sleep begins in stage 1 and progresses into stages 2, 3 and 4. After stage 4 sleep, stage 3 and then stage 2 sleep are repeated before entering REM sleep. Once REM sleep is over, the body usually returns to stage 2 sleep. Sleep cycles through these stages approximately four or five times throughout the night.
4. Sleep disorders. Theories of dreams interpretation.
Insomnia – is a common sleep problem; put simply, it is the inability to sleep.
Somnambulism – is the formal term for sleepwalking, which occurs during the deepest stages of sleep (3 &4).
A nightmare is a frightening dream that awakens the sleeper from REM sleep.
Night terrors occur in slow wave, non-REM sleep. Night terrors are characterized by sudden arousal from sleep and intense fear, usually accompanied by a number of physiological reactions such as rapid heart rate and breathing, loud screams, heavy perspiration, and physical movement.
Narcolepsy – is the overpowering urge to fall asleep.
Sleep apnea is a sleep disorder in which individuals stop breathing because the windpipe fails to open or brain processes involved to respiration fail to work properly.
The interpretation of dreams.
1) Freud's theory – the reason we dream is wish fulfillment. Our dreams contain a great deal of symbolism.
2) Problem solving theory – dream is a mental realm where we can solve problems and think creatively (Dmitriy Mendeleev's periodic table, Robert Louis Stevenson's Dr.Jekyll and Mr.Hyde and others).
3) Activation-Synthesis theory – dreams have no inherent meaning. Rather, they reflect the brains' efforts to make sense out of or find meaning in the neural activity that takes place during REM sleep. In this view, the brain's activity involves a great deal of random activity during REM sleep and dreams are an attempt to synthesize this chaos.