Consciousness
Stages of Sleep
Stage 1
Lasts for 5 or 10 minutes
Light state of sleep - brains powered down by 50% or more
Stage 2
Occupies 65% of the sleep cycle
Brain activity decelerates, heart rate slows, muscles relax
Stage 3 & 4
Occurs after about 10 to 30 minutes
In stage 3, delta waves appear 20-50% of the time; in stage 4 they appear more than half the time
Stage 5
REM Sleep - eyes move rapidly; brain is most active and vivid dreaming occurs
Lasts about 10/20 minutes; REM stages last progressively longer throughout sleep
Sleep Disorders
Insomnia
Difficulty falling or staying asleep
The most common sleep disorder
Narcolepsy
Rapid and unexpected onset of sleep
Some experience cataplexy - remain alert even if they can't move
Sleep Apnea
Blockage of the airway during sleep which results in daytime fatigue
People snore loudly, gasp, and sometimes stop breathing for about 20 seconds
Night Terrors
Sudden waking episodes characterized by screaming, perspiring, and confusion, followed by a return to deep sleep
Usually only last a few minutes and is typically harmless
Sleepwalking
Walking while fully asleep
Almost always occurs during non-REM sleep
Dreams
Process emotional memories, integrate new memories with established memories, stimulate threatening event, and recognize and consolidate memories
There are two general agreements about dreams:
1) Acetylcholine turns on REM sleep
2) The forebrain plays an important role in dreams
Dream Protection Theory
Created by Sigmund Freud
Dreams are the guardians of sleep; the ego is less able to keep sexual and aggressive instincts at bay than when awake
Dreamwork disguises sexual and aggressive impulses as symbols that represent wish fulfilment
Manifest Content: The details of the dream itself
Latent Content: The true, hidden meaning
Activation-Synthesis Theory
Dreams reflect inputs from brain activation origination in the pons, and the forebrain attempts to create a story
Dreams reflect the brain's attempt to make sense of random internal neural signals during REM sleep
Neurocognitive Theory
Dreams are a meaningful product of our cognitive capacities which shape what we dream about
Dreams often dramatize concerns that are important to us - implies they reflect more than just random neural impulses
Dream Continuity Hypothesis
There is continuity between sleeping and waking experiences; dreams can mirror life circumstances
Circadian Rhythm
Biological Clock
Term for the suprachiasmatic nucleus (SCN) in the hypothalamus that's responsible for controlling our levels of alertness
When it is disrupted it disturbs sleep and increases the risk of injuries, fatal accidents, and health problems
Cyclical changes that occur on a roughly 24-hour basis in many biological processes
People need about 7 to 10 hours of sleep a day
Multiple nights of sleep deprivation can cause a "sleep debt" which can require multiple nights to pay off
Sleep deprivation can cause depression, difficulties in learning new information and paying attention, and slowed reaction times
Hypnosis
Set of techniques that provide people with suggestions for alterations in their perceptions, thoughts, feelings, and behaviours
Enhances the effectiveness of psychodynamic and cognitive behavioural psychotherapies and treats pain, medical conditions, and habit disorders
Past Life Regression Theory
Therapeutic approach that hypnotizes and age-regresses patients to a previous life to the identify the source of a present-day problem
Sociocognitive Theory
Explains hypnosis based on people's attitudes, beliefs, and expectations
Dissociation Theory
Explains hypnosis based on a separation between personality functions that are normally well integrated
The hidden observer describes the dissociated, un-hypnotized part of the mind that hypnotists can access
The flexible observer is the phenomenon where the hidden observers report what the hypnotists suggest they report
Hallucinations
Thought of by some non-Western cultures as gifts of wisdom
from the gods and incorporate them into their religious rituals
Visual hallucinations can be caused by oxygen and sensory deprivation, epilepsy, fever, dementia, and migraine headaches
Auditory hallucinations can occur when patients mistakenly attribute their thoughts or inner speech to an external source
Mystical Experiences
Feelings of unity or oneness with the world, transcendence of space and time, feelings of wonder and awe, often with strong spiritual overtones
Psychoactive Drugs
Depressants
Alcohol is the most common depressant, and
also the most widely used and abused drug
overall
Sedative-hypnotics exert a calming,
sleep-inducing effect
At high doses can produce unconsciousness,
coma, and death
Grouped into three categories: barbiturates,
non-barbiturates, and benzodiazepines
Depress the effects of the central nervous system
Stimulants
Increase activity in the central nervous system;
heart rate, respiration, and blood pressure
Nicotine enhances positive emotions and
minimizes negative emotions
Cocaine is the most powerful natural
stimulant
Narcotics
Relieves pain, creates a sense of euphoria,
and induces sleep
Types of narcotics
Heroine
Morphine
Codeine
Psychadelics
Causing dramatic alterations of perception, mood, and thought
Can produce typically short-lived panic, paranoid delusions, confusion, depression, and bodily discomfort
Includes marijuana, LSD, and ecstasy
Out-of-Body Experiences
Individuals sense they are floating above their bodies and observing from above
Experienced when a person is medicated, using drugs, experiencing migraines or seizures, or when either extremely relaxed or extremely stressed
The sense of our consciousness leaving our body
Near-Death Experience
Reported by people who nearly died or thought they were going to die
Classical elements of NDE include passing through a dark tunnel, experiencing a bright light, a "life review", meeting spiritual beings, and then coming back to the body
The peace that accompanies an NDE may result from the massive release of endorphins
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