Zusammenfassung der Ressource
Chapter Five: Variations
in Consciousness
- Nature of Consciousness
- Variations in Awareness & Control
- Consciousness is the
awareness of internal
and external stimuli.
- STREAM OF CONSCIOUSNESS
Anmerkungen:
- -William James (1902) named it
-consciousness is in constant flux
-continually changing stream of mental activity
- Attention and Consciousness are clearly closely
related, they are NOT identical.
- MIND WANDERING
Anmerkungen:
- -refers to people's experience of task-unrelated thoughts.
-thoughts that are not related to what they are intentionally trying to do at a given moment.
- CONTROLLED PROCESSES
Anmerkungen:
- -judgements or thoughts that we exert some control over
- AUTOMATIC PROCESSES
Anmerkungen:
- -automatic processing and it's effects happen without our intentional control or effort.
- Unconscious Thought Effects
- If people are distracted or diverted from
"conscious Deliberation", some decisions may
actually be enhanced.
- Conscious thought is constrained by capacity
limitations. Advantage of unconscious thought it does
not have the same capacity constraints.
- Consciousness & Brain Activity
- Consciousness doesn't arise from any distinct
structure in the brain but rather from activity
in distributed networks of neural pathways.
- Most commonly used indicator of variations in consciousness has
been the EEG-ELECTROENCEPHALOGRAPH
Anmerkungen:
- -EEG is a device that monitors the electrical activity of the brain over time by means of recording electrodes attached to the surface of the scalp.
-records activity from broad swaths of the cortex
-
- EEG summarizes the rhythm of cortical activity in the brain in terms of
line tracings called BRAIN WAVES.
Anmerkungen:
- changes in EEG activity are closely related to variations in consciousness
- Brain wave tracings vary in amplitude (height) and frequency
(cycles per second cps)
- Brain-wave activity divided into 4 principal bands
- BETA (13-24 cps)
- Normal waking thought,
alert problem solving
- ALPHA (8-12 cps)
- Deep relaxation, blank
mind, meditation
- THETA (4-7 cps)
- Light sleep
- DELTA (under 4 cps)
- Deep sleep
- Biological Rhythms & Sleep
- Variations in consciousness are shaped in part by
biological rhythms.
- Organisms have internal "biological clocks" that some how monitor
the passage of time.
- BIOLOGICAL RHYTHMS are periodic fluctuations in physiological
functioning
- CIRCADIAN RHYTHMS are the 24-hour biological cycles found in humans
and many other species. Particularly influential in the regulation of sleep.
- Circadian rhythms can leave individuals physiologically primed to fall
asleep most easily at a particular time of day.
- Circadian rhythms generally persist even when external time cues are
eliminated.
- SUPRACHIASMATIC NUCLEUS (SCN) sends signals to the pineal gland, whose
secretion of the hormone melatonin plays a key role in adjusting biological
clocks.
Anmerkungen:
- When exposed to light, some receptors in the retina send direct inputs to a small structure in the hypothalamus called suprachiamatic nucleus(SCN)
- Ignoring Circadian Rhythms
- Sleep Debt - accumulates, and must be paid back by
getting extra sleep
Anmerkungen:
- If you get less than the amount of sleep that you need, you accumulate sleep debit.
- Jet Lag
Anmerkungen:
- flying across several time zones, your body keeps time as usual, even though the official clock time changes.
- Shift Work
Anmerkungen:
- affects worker's mental and physical health
- Realigning Circadian Rhythms
- can give small doses of melatonin
- Circadian friendly rotation schedules for shift work
- bright light administration
- Sleep & Wake Cycle
- Theorists agree that sleep must be adaptive
- Devices used to monitor sleep
- Electroencephalograph -
EEG
Anmerkungen:
- monitors electrical activity of the brain
- Electromyograph -
EMG
Anmerkungen:
- records muscular activity and tension
- Electrooculograph - EOG
Anmerkungen:
- Other instruments for
heart rate,breathing,
pulse rate,& body
temperature
- Stages of Sleep
- Stage 1
- Brief, transitional (1-7 min)
- Alpha waves give way to lower
frequency Theta waves
- Hypnic Jerks
Anmerkungen:
- those brief muscular contractions that occur as people fall asleep
- Stage 2
- Lasts 10-25 min
- Brief bursts of higher-frequency
brain waves, called SLEEP
SPINDLES appear
- Stages 3&4
- 30 min
- Slow-Wave Sleep
(SWS)
Anmerkungen:
- -during which high amplitude, low frequency delta waves become prominent in EEG recordings
- Delta waves
- Stage 5:REM
Anmerkungen:
- REM sleep is a relatively deep stage of sleep marked by rapid eye movements;high frequency, low-amplitude brain waves; and vivid dreaming
- REM -rapid eye movements
- use electooculograph to monitor lateral (side to
side) movements that occur beneath the sleeping
person's closed eyelids
- Deep stage of sleep, people are relatively hard to
awaken from it.
- marked by irregular breathing and pulse rate.
- body movements are minimal
- EEG activity is dominated by high-frequency Beta waves that
resemble those observed when people are alert and awake
- Rem dreams may be more frequent, vivid and memorable
- First REM period is short lasting only a few minutes. Each
cycle they get longer peaking at 40-60 min
- Non-REM Sleep (NREM)
Anmerkungen:
- Non-REM sleep consists of sleep stages 1through, which are marked by an absence of rapid eye movements, relatively little dreaming, and varied EEG activity.
- NREM intervals tend to get shorter, and
descents into NREM stages usually become
more shallow each time people cycle
through
- Age Trends in Sleep
- Age alters the sleep cycle
- Babies
- Spend much more time in
the REM stage than adults
- Newborns only have REM
and NREM sleep types
- Adults
- average amount of total
sleep time also declines
with advancing age.
- Older adults tolerate sleep
deprivation with less
impairment than younger
adults
- Doing without: Sleep Deprivation
- Sleep Restriction or Partial
Sleep Deprivation
Anmerkungen:
- Occurs when people make do with substantially less sleep than normal over a period of time.
- More negative effects than we assume
- can impair attention, reaction time, cognitive speed and
accuracy, motor coordination and decision making.
- Sleep loss can affect physiological processes in ways that may
undermine physical health.
- Selective Deprivation
- Effects of REM deprivation
- little impact on daytime functioning and task
performance
- It is necessary to awaken subjects more and more often to deprive them
of REM sleep because they spontaneously shift into REM more and more
frequently as the nights go by
- When REM deprivation comes to an end and subjects are allowed to sleep without
interruption, they experience a rebound effect. They spend extra time in REM to make
up for the deprivation.
- Why do we need REM? for memory consolidation
Anmerkungen:
- -REM and slow-wave sleep contribute to firming up learning that takes place during the day.
REM sleep and slow-wave sleep each promote different types of memory.
- The length of time spent in REM and SWS correlates with subject's
increments in learning
- Sound sleep habits should facilitate learning.
- REM sleep appears to foster the process of NEUROGENESIS
Anmerkungen:
- -Neurogenesis refers to the formation of new neurons.
-neurogenesis contributes to learning
- Neural & Evolutionary Bases of Sleep
- important to sleep & wakefulness is
the RETICULAR FORMATION
- ASCENDING RETICULAR ACTIVATING
SYSTEM (ARAS)
Anmerkungen:
- consists of the fibres running through the reticular formation that influence physiological arousal.
- Activity in the PONS and adjacent areas in the
midbrain seems to be critical to the generation of
REM sleep
- The ebb & flow of sleep and waking is regulated
through activity in a constellation of interacting brain
centres.
- Evolutionary significance of sleep hypothesis
- 1. Sleep evolved to
conserve energy
- 2.The inactivity of sleep is adaptive
because it reduces exposure to
predators and the consumption of
precious resources
- 3. Sleep is adaptive because it helps animals restore bodily
resources depleted by waking activities
- Sleep Disorders
- 78 types of sleep disorders
- Insomnia
Anmerkungen:
- -refers to chronic problems in getting adequate sleep.
- Insomnia increases with age and is
about 50% more common in women
than men.
- most common sleep disorder, occurs in
3 basic patterns
- 1.)difficulty in falling asleep initially
- 2.) difficulty in remaining asleep
- 3.)persistent early morning awakening
- Has many causes
- Is frequently a side effect of
emotional problems such as
depression, or of significant stress
- recent research has suggested that the primary
cause of insomnia may be that some people are
predisposed to insomnia because they have a
higher level of physiological arousal than the
average person. this is the HYPERAROUSAL
MODEL
- Treatment
- most common medical treatment is the prescription of 2 classes of drugs
- BENZODIAZEPINE SEDATIVES (Dalmane,
Halcion, and Restoril)
- originally developed to relieve anxiety
- NONBENZODIAZEPINE SEDATIVES
(Ambien, Sonata, Lunesta)
- newer and designed primarily for sleep problems
- Sedatives can be a poor long term solution because of carry over effects and can
cause overdose in combination with alcohol or opiate drugs
- Sedatives gradually become less effective and need to be used cautiously and
conservatively.
- Relaxation procedures and behavioural interventions can be helpful
for many.
- Narcolepsy
Anmerkungen:
- is a disease marked by sudden and irresistible onsets of sleep during normal waking periods
- is relatively infrequent (0.05% of
population)
- appears to be genetically predisposed to
disease
- goes directly from wakefulness into REM
sleep usually for a short period of
time(10-20 min)
- Sleep Apnea
Anmerkungen:
- -involves frequent, reflexive gasping for air that awakens a person and disrupts sleep
- Occurs when a person stops breathing for 10
seconds and at least 5 such events per hour of sleep
- may be treated via lifestyle modifications
- generally, sleep disordered breathing that goes
untreated may interfere with memory consolidation
associated with sleep
- Nightmares
Anmerkungen:
- -are anxiety-arousing dreams that lead to awakening, usually from REM sleep
- occur during REM sleep
- Mainly a problem among children
- Night or Sleep Terrors
Anmerkungen:
- -are abrupt awakenings from NREM sleep, accompanied by intense autonomic arousal and feelings of panic
- usually occurs during stage 4 sleep early in the night
- don't usually recall a coherent dream, may remember a simple
frightening image
- occur in adults but especially common in children age 3-8
- Somnambulism or Sleep walking
Anmerkungen:
- - occurs when a person arises and wanders about while remaining asleep
- tends to occur in the first 2 hours of sleep
- causes of this disorder are unknown and appears to have a genetic
predisposition
- contrary to popular myth, it is safe to wake people
- REM Sleep Behaviour Disorder(RBD)
Anmerkungen:
- -is marked by potentially troublesome dream enactments during REM sleep
- occurs mostly in men who typically begin
experiencing this in their 50-60's
- they may talk, yell, flail,gesture
- could hurt themselves or bed partner
- cause appears to be some sort of deterioration in the
brainstem structure
- treatment is difficult and co-exist with other
sleep disorders
- World of Dreams
- Conventional view - dreams are mental
experiences during REM sleep that have
storey like quality with vivid visual imagery,
often bizarre and are regaurded as
perceptually real by the dreamer
- dreams are not the exclusive property
of REM Sleep
- non-REM dreams appear to be less
vivid, visual and story like than REM
dreams
- Contents of Dreams
- most dreams are relatively
mundane
- One nearly universal element of dreams is a
coherent sense of self- we almost always experience
dreams from a first person perspective.
Anmerkungen:
- typically dreams are self centred.
- contents of dreams vary because people in
different societies deal with different worlds
while awake
- Links between Dreams & Waking Life
- DAY RESIDUE
Anmerkungen:
- - Coined by Freud
-contents of waking life often tended to spill into dreams.
- LUCID DREAMS
Anmerkungen:
- - are dreams in which people can think clearly about the circumstances of waking life and the fact that they are dreaming, yet they remain asleep in the midst of a vivid dream.
-in some cases dreamer may be able to exert some control over the dream
- Theories of Dreaming
- Freud believed that the principle
purpose of dreams is wish
fulfillment.
- Manifest Content
Anmerkungen:
- consists of the plot of a dream at the surface level
- Latent Content
Anmerkungen:
- refers to the hidden or disguised meaning of the events in the plot
- Rosalind Cartwright proposed that
dreams provide an opportunity to work
through everyday problems.
- Cognitive problem solving view
Anmerkungen:
- there is considerable continuity between waking and sleeping thought.
- Hobson & McCarley argue dreams are simply
the by-product of bursts of activity
emanating from subcortical areas
- Activation-synthesis model
Anmerkungen:
- -propose that dreams are side effects of the neural activation that produces"wide-awake" brain waves during REM sleep
-Does NOT assume dreams are meaningless.
- Hypnosis: Altered Consciousness or Role Playing?
- James Braid who popularized the term HYPNOTISM in 1843
- Hypnotic Induction & Susceptibility
- Hypnosis is a systematic procedure that typically produces
a heightened state of suggestibility
- Hypnotic Induction
Anmerkungen:
- -many techniques can be used. Swinging pendulum, suggestion of relaxation etc.
- Gradually most subjects succumb and become
hypnotized
- Hypnotic Suceptibility
Anmerkungen:
- -Responsiveness to hypnosis is a stable, measurable trait.
-people who are responsive to suggestion under hypnosis are just as responsive to suggestion without being hypnotized
- is NOT unique to hypnosis and is part of a broader
trait characterized as IMAGINATIVE
SUGGESTIBILITY
- Hypnotic Phenomena
- Anesthesia
Anmerkungen:
- Under the influence of hypnosis some participants can withstand treatments that would normally cause considerable pain. some doctors and dentists have used hypnosis as a substitute for anesthetic drugs
- Sensory Distortions &
Hallucinations
Anmerkungen:
- hypnotized participants may be led to experience auditory or visual halluncinations
- Disinhibition
Anmerkungen:
- -hypnosis can sometimes reduce inhibitions that would normally prevent subjects from acting in ways that they would see as socially undesirable.
- Theories of Hypnosis
- Social-Cognitive Theory of
Hypnosis:Hypnosis as Role
Playing
- The view that hypnosis produces a normal mental state in which
suggestible people act out the role of a hypnotized subject and behave
as they think hypnotized people are suppose to act.
- Hypnosis is not the result of a person being in a "trance" but
rather results from normal everyday processes including an
individual's expectations and attitudes
- hypnosis may facilitate recall, some studies have tended to find hypnotized
participants make more memory errors than nonhypnotized participants, even though
they often feel more confident about their recollections.
- Hypnosis as an Altered State of
Consciousness
- hypnosis creates a dissociation in consciousness
- DISSOCIATION is a splitting off of mental processes into 2
seperate simultaneous streams of awareness
- One stream is in communication with the
hypnotist and the external world, while the other
is a difficult to detect "hidden observer"
- Appealing aspect of this theory is that divided consciousness is a
common, normal experience. ie highway hypnosis
- Meditation: Pure Consciousness or Relaxation?
- Meditation refers to a family of practices that train attention to heighten
awareness & bring mental processes under greater voluntary control
- In North America, most widely practised are yoga, Zen, and transcendental meditation(TM)
- two main styles of of meditation
- Focused Attention
- attention is concentrated on a specific object,
image, sound or bodily sensation such as
breathing
- The intent in narrowing attention is to clear the mind
of its clutter
- Open Monitoring
- attention is directed to the contents of
one'smoment-to-moment experience in a nonjudgmental
and nonreactive way
- The intent in expanding attention is to become a
detached observer of the flow of one's own sensations,
thoughts and feelings
- Both seek to achieve a"higher" form of consciousness than people normally
experience
- Long Term Benefits
- may have some value in reducing the effects of stress
- Research suggests that meditation can improve mental health while
reducing anxiety and drug abuse
- recent studies suggest meditation may have the potential to modify brain
structure
- Critics wonder about placebo effects, sampling bias and other
methodological problems may contribute to some of the
reported benefits
- Altering Consciousness with Drugs
- Principal Abused Drugs
- Psychoactive drugs are chemical substances that
modify mental, emotional, or behavioural
functioning
- Narcotics/Opiates
Anmerkungen:
- are drugs derived from opium that are capable of relieving pain
common side effects lethargy nausea impaired mental and motor functioning
- Sedatives
Anmerkungen:
- are sleep inducing drugs that tend to decrease central nervous system activation and behavioural activity
side effects drowsiness, unpredictable emotional swings, severe impairments in motor coordination and mental functioning
- Stimulants
Anmerkungen:
- -are drugs that tend to increase central nervous system(CNS) activation and behavioural activity
-side effects restlessness,anxiety, paranoia and insomnia
- Hallucinogens
Anmerkungen:
- - are a diverse group of drugs that have a powerful effect on mental and emotional functioning, marked most prominently by distortions in sensory and perceptual experiences
-
- Cannabis
Anmerkungen:
- - is the hemp plant from which marijuana, hashish and THC are derived
-side effects may include anxiety, sluggish mental functioning and impaired memory.
-recent studies have reported an unexpected link between cannabis use and severe psychotic disorders, including schizophrenia
-
- Alcohol
Anmerkungen:
- -encompasses a variety of beverages containing ethyl alcohol
-side effects include severe impairment in mental and motor functioning, mood swings, and quarrelsomeness
- MDMA 'Ecstasy"
Anmerkungen:
- is a compound drug related to both amphetamines and hallucinogens, especially mescaline
-side effects include increased blood pressure, muscle tension, sweating, blurred vision, insomnia, and transient anxiety
-research is in its infancy, so conclusions about its risks are still ongoing
- does not appear to be especially addictive, but pychological dependence clearly can become a problem for some
- may have subtle long term effects on cognitive functioning
- concerns that recently ecstasy pills that are laced with crystal meth
- Drug effects vary from person to
person, frequency of use, and
quantity consumed.
Multifactorial causation applies
to drug effects
- Tolerance refers to a
progressive decrease
in a person's
responsiveness to a
drug.
- Psychoactive drugs work primarily
by altering neurotransmitter activity
in the brain at the synapses.
- Drug Dependance
- people can become either physically or
psychologically dependent on a drug
- Physical dependance
Anmerkungen:
- -exists when a person must continue to take a drug to avoid withdrawal illness
-
- conditioning is implicated in
dependency in many ways
- Psychological dependance
Anmerkungen:
- -exists when a person must continue to take a drug to satisfy intense mental and emotional craving for the drug.
- is possible with all
recreational drugs, it
seems rare for
hallucinogens
- both types of dependancy are established gradually
with repeated use and reflect alterations in synaptic
transmission
- Drugs & Health
- Overdose
- any drug can be fatal if a
person takes enough of it
- Sedatives, narcotics and alcohol
carry the greatest risk
- these drugs are synergistic with each other
- respiratory system grinds to a halt
causing death within a brief period
- Direct Effects
Anmerkungen:
- - are physiological damage
- Drugs cause tissue
damage directly
- Indirect Effects
Anmerkungen:
- health impairing behaviour
Negative effects of drugs on physical health are often indirect results of the drug's impact on attitudes, intentions, and behaviour.
ie not eating or sleeping, impaired motor coordination etc