Consciousness
Consciousness- your immediate awareness of thoughts, sensations,
memories, and the world around you
William James (1892) described consciousness as an ongoing river or
stream of mental activity- always changing but perceived as unified and
unbroken.
The first psychologists tried to use introspection to understand the
human mind- verbal self-reports that tried to describe the “structure” of
conscious experiences.
Consciousness was rejected as a source of study early in the 20th
century in favor of studying specific behavior which could be measured
By the 1950s there was a return to study of consciousness as it was
understood that a pure study of behavior was impossible if we didn’t
understand the role conscious mental processes play in behavior. Also better
ways of studying conscious experiences were devised.
Biological Clocks
Circadian rhythms are biological processes that vary predictably
over a 24 hour period. (Circadian- Latin for “about” and “day”
Suprachiasmatic nucleus (SCN) is a cluster of neurons in the
hypothalamus that governs the timing of circadian rhythms. As there is a
decrease in light detected by visual receptors, the SCN triggers an increase
in melatonin which is a hormone produced by the pineal gland. This
produces feelings of sleepiness.
Free-running conditions – 25-hour day- Under conditions marked
by an absence of normal light/darkness cues, people drift toward a 25 hour
day, controlled by the SCN. When returning to regular light conditions, they
reset their biological clock and rhythms become synchronized again.
Jet lag is experienced when your circadian rhythms are out of sync
with daylight and darkness cues. Shift workers often experience fet lag as
they rotate to new shifts.
Sleep
Sleep was better understood with the invention of the
Electroencephalograph scientists were able to measure electrical activity of
the brain- brain waves. (EEG)- electroencephalogram is a graphic record
of these brain waves.
REM sleep – active sleep is associated with higher body and brain activity,
during which dreaming often occurs.
NREM sleep- quiet sleep occurs as the body’s functions and brain activity
slow down- it is divided into 4 stages.
Sleep patterns
Beta brain waves are associated with alert wakefulness
Alpha brain waves are associated with relaxed wakefulness
Hypnagogic hallucinations – vivid sensory phenomena that can
occur at the onset of sleep. One is the vivid sensation of falling- myoclonic
jerk which is also known as the sleep start.
The first 90 minutes of sleep:
Stage 1 NREM-when alpha brain waves are replaced by slower theta
brain waves- only a few minutes.
Stage 2 NREM- onset of true sleep, with short bursts of brain activity
that last a second or two- sleep spindles
Stage 3 and Stage 4 of NREM- characterized by delta brain wavesslow-wave sleep
REM sleep- visual and motor neurons in the sleeper’s brain fire
repeatedly as they do during waking; the sleeper’s eyes dart back and forth
behind the closed eyelids- and voluntary muscle activity is suppressed
(hopefully)
After the first 90 minutes, the periods of REM sleep become longer
and NREM sleep periods become shorter.
Changes in sleep patterns over the lifespan- quantity and quality of sleep
change over the lifespan, with sleep decreasing from birth onward, but the
amount of time in Stage 2 NREM sleep increasing
Purposes of sleep
Sleep deprivation studies – show a biological need for sleep under
deprivation studies, there will be microsleeps that last only a few seconds.
REM deprivation studies-show that when deprived of REM sleep,
the sleeper will experience REM rebound – longer periods of time in REM
stage at the first opportunity to sleep. There is also NREM rebound when
people are deprived of NREM stages 3 & 4
Restorative theory of sleep is the view that sleep promotes
physiological processes that restore the body and mind.
NREM sleep for restoring the body
REM sleep for restoring brain & memory functions
Adaptive theory of sleep- evolutionary theory of sleep says that
different animals’ sleep patterns evolved over time to promote survival.
Sleep disorders- serious disturbances in the normal sleep pattern that cause
distress and impaired function during the day.
Insomnia is the inability to fall asleep, stay asleep, or feel rested by
sleep- most common sleep complaint among adults. Sleep hygiene theories
suggest that a troubled sleeper only associate the bed with sleeping, not other
activities.
Sleep apnea is a sleep disorder in which the person repeatedly stops
breathing during sleep. It can result in danger driving, as well as heart risks.
One cause has been shown to be obesity.
Sleepwalking (somnambulism) is characterized by walking or doing
other acts during stage 3 or 4 NREM sleep. Bedwetting also occurs during
these deep sleep stages.
Night terrors occur during stage 3 or 4 NREM sleep- intense fear,
panic, frightening sensations, but no recall of the episode the next morning.
Most children resolve these by adolescence.
Sleep bruxism is teeth grinding during sleep.
Parasomnias are arousals or activities during sleep- sleepwalking,
night terrors, etc.
REM sleep behavior disorder is a parasomnia in which the dreamer
acts out the dream. There may be inadequate control of activity due to
impairement of the lower brain centers.
Narcolepsy is excessive and inappropriate daytime sleepiness and
lapses into sleep during the day. Modafinil does seem to reduce daytime
sleepiness.
Dreams
Sleep thinking is vague, bland, uncreative, thoughtlike ruminations
about real-life events during sleep.
Dream is a storylike episode of mental imagery during sleep.
Characteristics of dreams:
Intense emotions
Illogical content or organization
Bizarre sensations
Bizarre details
Difficult-to-remember dream images
Brain during REM sleep- brain scans show brain activity during
REM sleep is different from activity during waking or slow wave NREM
sleep.
Primary visual cortex and frontal lobes are shut down during
REM sleep, so the sleeper is cut off from information about the outside
world, and from brain centers involved in rational thought. The amygdala
and hippocampus (located in the limbic system, the emotional brain) are
highly active during REM sleep.
REM and memory consolidation-REM sleep increases after learning a
novel task, and deprivations of REM sleep interrupts new learning.
Themes of dreams- dream themes often reflect daily concerns of the
dreamer. Environmental conditions can affect dream content during the
dream.
Loss of memory for dreams- we are more likely to remember our
dreams if we wake up during them. The more vivid or bizarre or emotionally
intense a dream is, the more likely it is that we would remember it.
Distractions upon waking will destroy our recall. Most experiences
occurring during sleep are not remembered well.
Nightmare is a frightening or unpleasant dream
Lucid dreams are dreams in which the sleeper maintains some
awareness that one is dreaming- even to being able to influence the material
within the dream.
Theories of dreaming
Sigmund Freud was the first to suggest dream content could
be useful in understanding people’s motivation, dreams, and wishes. He
called dreams “the royal road to the unconscious”. He described their
content:
Manifest content- dream imagery itself
Latent content- disguised psychological meaning of the
dreams. Later theorists rebutted his ideas, although Jung built his entire
theory upon dream analysis.
Activation-synthesis model of dreaming says that dreaming is
our subjective awareness of the brain’s internally generated signals during
sleep. Meaning is found as we decode the chaotic dream images. There is
really no difference in waking and dreaming consciousness, only the source
of information differs. So our conscious interpretations of what is occurring
when we are asleep tells us about the interpreter more than about the dream.
Hypnosis is a cooperative social interaction in which a person responds to
suggestions with changes in perception, memory, and behavior. Best
candidates are those who view the process positively, very receptive.
Effects of hypnosis can be as profound as sensory and perceptual
changes, hallucinations, even.
Posthypnotic suggestion is when a suggestion made during
hypnosis for a person to do a specific act is carried out later, outside the
hypnotic state. It can be helpful with cognitive-behavior therapy in weightloss programs.
Posthypnotic amnesia occurs when a hypnotic suggestion
suppresses the ability to recall specific events that occur before or during
hypnosis.
Hypermnesia occurs when a hypnotic suggestion enhances a
person’s memory for past events. Hypnosis does not improve memory
accuracy, though. This can be used to enhance a person’s memory for past
events, but it can increase confidence in memories that are incorrect- false
memories-Pseudomemories. A problem of distorted or contrived memories
occurs in age regression- the use of hypnosis to enable recall for an earlier
developmental period (or a past life, if you want to go there.)
Limits of hypnosis
A person cannot be hypnotized against his will
Hypnosis cannot make you stronger than your actual
capabilities or induce talents not already present
Hypnosis can increase motivation or concentration
Hypnosis cannot make you do things that are against
your morals or values.
Consciousness divided
Neodissociation theory of hypnosis says that a hypnotized person
consciously experiences one stream of mental activity that is responding to
the hypnotist’s suggestions, while a second, dissociated stream of mental
activity is also operating- the hidden observer.
Meditation- techniques that induce an altered state of focused attention and
heightened awareness.
Concentration techniques involve focusing awareness on a visual
image, breathing, a word – mantra that is mentally repeated.
Opening-up techniques- present-centered awareness of the passing
moment without judgment.
Transcendental meditation- sitting in a comfortable position with
eyes closed, silently focusing attention on a mantra. Done twice daily for
about 20 minutes to quiet the mind and produce an altered state of pure
consciousness.
Effects of meditation- lowered physiological arousal, lowered blood
pressure, decrease in heart rate, and changes in brain waves.
Psychoactive drugs are chemical substances that alter normal
consciousness, perception, mood or behavior.
Addiction- condition in which a person feels compelled to take a
specific drug.
Physical dependence- condition in which a person’s body and brain
chemistry have physically adapted to a drug
Tolerance- a condition in which increasing amounts of a physically
addictive drug are needed to produce the original, desired effect.
Withdrawal symptoms – unpleasant physical reactions to the lack of
the drug, plus an intense craving for it. Drug rebound effect is withdrawal
symptoms that are opposite to the drug’s action (withdrawal from heroin
produces diarrhea, as the normal function of heroin is to slow GI
contractions, producing constipation)
Effects within the synapses-drugs influence brain activity by
increasing or decreasing neurotransmitter amounts or by blocking,
mimicking, or influencing a particular neurotransmitter’s effects.
Drug abuse is recurrent drug use that results in disruptions in academic,
social or occupational functioning, or legal or psychological problems.
Factors involved in drug abuse:
Social norms favorable toward drug use
Availability and cost of the drug
Drug-taking behavior of role models
Occupational, social & academic problems
Association with drug-using peers
Rebelliousness and alienation
Depressants are psychoactive drugs that depress or inhibit CNS activity.
Their effects are additive.
Alcohol can be used in small amounts to reduce tension or anxiety.
But people who succumb to alcohol’s allure no longer use in small amounts.
14 million Americans have serious alcohol problems- half are considered
alcoholics- physically addicted to alcohol. There is a genetic tendency to
abuse alcohol. Alcohol depresses the activity of neurons throughout the
brain and impairs cognitive abilities- concentration, memory, speech,
balance and coordination. If the alcoholic quits drinking, s/he will
experience physical withdrawal symptoms- the shakes, DTs- delirium
tremens. Alcohol lessens inhibitions by depressing brain centers that govern
judgment and self-control- so it is not thought of as a depressant, but that is
the ultimate effect. Also, because of the inhibiting effect on the frontal lobes,
most criminals in prison report their crimes were committed under the
influence.
Barbiturates depress activity in the brain centers that control arousal,
wakefulness, and alertness. They can depress the respiratory centers,
resulting in death after overuse. Barbiturates include Seconal, Nembutal, &
Quaalude.
Tranquilizers are depressants that relieve anxiety- Xanax, Valium
Inhalants (white out, glue, solvents, whipping creams under pressurewhippets) are inhaled to produce alteration in consciousness- can act to
dissolve the thin protective tissue between the brain and sinuses- literally
dissolving brain tissue.
Opiates (narcotics) are addictive drugs that relieve pain and produce
euphoria. Natural opiates include opium, derived from the opium poppy,
morphine, and codeine. Synthetic opiates are heroin, methadone, and
Percodan, and Demerol. Opiates mimic the brain’s natural painkillersendorphins. Most frequently abused opiate is heroin.
Stimulants are mildly addicting, as they increase brain activity
Caffeine found in coffee, tea, cola drinks, chocolate, and some
medications, increases mental alertness and wakefulness- most widely used
psychoactive drug in the world.
Nicotine is extremely addictive, found in tobacco products.
Amphetamines stimulate brain activity, increase alertness, and
reduce fatigue. They elevate mood and suppress appetite. Benzedrine &
Dexedrine are prescription amphetamines. Methamphetamines are illegal,
but flooding the US, as they can easily be made in homemade labs. Injected
or smoked.
Cocaine is an illegal stimulant derived from the coca tree- snorted in
purified, powdered form. Crack is a more concentrated form, smoked rather
than inhaled. Produces intense euphoria, mental alertness, self-confidence.
Stimulant-induced psychosis is a schizophrenia-like symptom set
that results from prolonged use of amphetamines or cocaine.
Psychedelics drugs create perceptual distortions, alter mood, and affect
thinking. Psychedelic means “mind-manifesting”
Mescaline naturally occurs in peyote cactus. Psilocybin is derived
from the Psilocybe mushroom- magic mushrooms.
LSD is a synthetic psychedelic drug. LSD and psilocybin are similar
chemically to serotonin, which regulates mood and sensations.
Marijuana is derived from the help plant, and is one of the most
widely used illegal drugs. THC is the active ingredient in marijuana.
Hashish is made from the resin of the hemp plant and is particularly potent.
Receptor sites in the brain that are triggered by THC also work for the
natural brain chemical called anandamide- it reduces pain sensations.