Consciousness
the awareness people have of themselves and the environment around them.
• The level and state of consciousness vary. Different states of consciousness are associated with different brain wave patterns.
Brain waves
tracings that show the kind of electrical activity going on in the brain. Scientists use an electroencephalograph, or EEG, to record these waves.
Main types of brain waves
alpha, beta, theta, and delta.
explaining waking consciousness
- Stream of information resulting from the activity of the thalamus which analyses and interprets information.
- Consciousness may only be the ‘tip of the icebergs’ that includes unconscious mental activities
- Consciousness is also viewed as an adaption allowing us to get along with others in our group (humans).
The rhythms of sleep
Stage 1 Stage 2 Stage 3 Stage 4 REM Sleep NREM Sleep
REM
Brain/psychological, repair, brain growth, neurotransmitters, memory
NREM
body/physiological, repair, immune system, growth hormone
Circadian rhythms
biological cycles that occur about every twenty-four hours. Sleep follows a circadian rhythm. Hormone secretion, blood pressure, body temperature, hunger and urine production also have circadian rhythms. Is governed by an area of the hypothalamus. Jet lag is the result of desynchronization of the circadian rhythm.
Infradian rhythms
biological cycles that take longer than twenty-four hours. For example, women’s menstrual cycles occur about every twenty-eight days.
Ultradian rhythms
biological cycles that occur more than once a day. Sleep follows an ultradian rhythm of about ninety minutes as well as a circadian rhythm. Alertness and hormone levels also follow ultradian rhythms.
Sleep
- Endogenous biological rhythms originate from inside the body rather than from the outside environment.
- Biological clocks in the body regulate the sense of time.
- The suprachiasmatic nucleus regulates circadian rhythms of sleep.
- Researchers use EEGs, EMGs, EOGs, and EKGs to record sleep patterns.
- There are five stages of sleep. At each stage, different types of brain waves function, and heart rate, breathing, and temperature vary.
- During REM sleep, heart rate and breathing become irregular, eyes move rapidly, and muscles relax. Dreams are most vivid during REM sleep.
- Sleep patterns change as people age, with most people needing less sleep as they get older.
- Sleep disorders include insomnia, narcolepsy, and sleep apnoea.
Restoration theory of why we sleep
- We sleep so that physiological and biological repairs can be made
- Without sleep health deteriorates
Evolutionary theory of why we sleep
- Energy conservation
- Predator avoidance
- Foraging requirements
- To waste time
Dreams
- Sigmund Freud believed that dreams allow people to express unconscious wishes. He said the manifest content of dreams, or the dream’s plot, symbolizes the latent content, or hidden meaning.
- The activation-synthesis theory proposes that neurons in the brain randomly activate during REM sleep. Dreams arise when the cortex tries to make sense of these impulses.
- Some researchers think dreams express people’s most pressing concerns, while others think dreams arise during the brain’s routine housekeeping chores such as eliminating or strengthening neural connections.
Altered states on consciousness
• Altered states are induced states of consciousness and include hypnotic states, meditative states, and drug-induced states.
Hypsosis
• In hypnosis, a hypnotist makes suggestions to a person. One theory states that people in hypnosis divide their consciousness into two parts. Other theories say that people merely play a role when hypnotized.
Meditation
the practice of focusing attention.
drugs
- Psychoactive drugs are usually used for recreational rather than medical purposes, though some have legitimate medical uses. These drugs change sensory experience, perception, mood, thinking, and behaviour.
- Recreational drugs include stimulants, sedatives, narcotics, and hallucinogens.
- Drugs work by affecting neurotransmitter function in various ways.
- The effect of any drug depends on many factors such as the amount of the drug, how the drug is administered, and the user’s mood, personality, and motivation.
- Chronic use of drugs can result in tolerance, withdrawal symptoms, physical dependence, or psychological dependence.
Day dreaming and fantasy
- Spontaneous shifts of attention away from the here and now into a make-believe world.
- Urge to daydream peaks about every 90 minutes
- Day dreams may provide stress relief and encourage creativity
