Chapter 6 Flashcards
The Aware Mind: Elements of Consciousness
addiction
- a compulsive physical or psychological dependence on a substance or activity that continues in spite of negative consequences
- choices are made on the basis of short-term outcomes (getting high) rather than long-term outcomes (staying out of jail)
circadian rhythms
a daily biological rhythm
consciousness
a state of awareness to ongoing experiences occuring internally and externally in the world around us
dreaming
a mental state that usually occurs during sleep that features visual imagery
hallucinogen
a drug that stimulates the experience of false perceptions
lucid dreaming
- a conscious awareness of dreaming accompanied by the ability to control the content of the dream
- the result of the the dorsolateral prefrontal cortex (involved in higher-order executive functions and voluntary behaviour) “waking up” during a dream
psychoactive drugs
any drug with the capability of altering a person’s state of consciousness
seizure
an abnormal level of brain activation with a sudden onset
self-awareness
the special understanding of the self, as distinct from other stimuli
sleep
a normal state of consciousness characterized by reduced awareness of external stimuli
stimulant
any drug that increases the activity of the nervous system
tolerance
the need to administer greater quantities of a drug to achieve the same subjective effect
waking
a normal state of consciousness characterized by alertness and awareness of external stimuli
withdrawal
physical responses to the removal of some habitually administered drugs
the meaning of consciousness according to William James vs. Sigmund Freud
- James coined the term “stream of consciousness” to capture the unbroken flow of conscious awareness
- Freud used the term “consciousness” to refer to the aspect of the mind that could be retrieved voluntarily
benefits of varying states of awareness
- allows animals to repair their bodies and conserve energy
- maximizes safety (e.g. horses sleep in the open, but for only 1-2 hours daily, whereas rabbits sleep in burrows and sleep for at least 8 hours daily)
advantage to consciousness as an awareness of ongoing sensations
the ability to choose responses rather than to respond instinctively (e.g. when hearing a sound, a conscious animal can choose whether to ignore, flee, or pause to obtain more information)
the rouge test and its significance (Lewis & Brooks-Gunn, 1979)
A dot of rouge is placed on a child’s forehead, and the child looks in the mirror. Before the age of 18 months, children don’t seem to understand the mirror image as their own. At 18 months, children rub the spot of dye off or turn their bodies to get a better look.
This experiment demonstrates self-awareness.
animals that demonstrate self-awareness (via the rouge test)
- primates (chimpanzees, orangutans, human-raised gorillas)
- bottle-nosed dolphins
- Asian elephants
- magpies
- parrots
examples of social animals
- dolphins
- chimpanzees
- elephants
The brain uses only _ % more energy when people are focused, compared to when they are unfocused.
5%
default mode network (DMN)
a state in which the brain maintains a high level of unconscious, background activity as it helps prepare the brain for conscious thought
People spend about _ % of their waking hours in a DMN state.
50%
two examples of how brain damage relates to consciousness
- prosopagnosia: a condition in which patients are unable to recognize faces, despite having no difficulty naming other objects; it is the result of damage to the fusiform face area (FFA)
- Capgras syndrome: a condition in which patients are convinced that imposters have taken the place of familiar people; it is probably the result of damage to visual areas of the brain and the amygdala
epilepsy
a condition related to recurring seizures
three causes of seizures
- brain injury
- infection
- inhibition of the neurotransmitter GABA
two types of seizures
- Partial seizures originate in the focal area of the brain, and spread to cortical and subcortical structures. They are accompanied by an “aura” (premonition) that a seizure is about to occur, and can produce distortions of consciousness (i.e. feelings of déjà vu or jamais vu).
- Generalized seizures are characterized by abnormal activation of circuits connecting the cerebral cortex and the thalamus. They are not accompanied by an aura, and consciousness is lost during an episode.
two major categories of generalized seizures
- Tonic-clonic seizures begin with a loss of consciousness, the inability to breathe, and intense, violent muscular contractions that may result in physical injuries (i.e. broken bones). These phases are then followed by a period of coma that last about 5 minutes.
- Absence seizures begin with a loss of consciousness, and limited motor movements (i.e. blinking and head/eye movements), however, an awareness of sourroundings is still present.
three examples of circadian rhythms
- birth seasons
- migration patterns
- menstrual cycles
Circadian rhythms respond to a combination of…
- internal biological clocks controlled by the hypothalamus, that provide an approximate schedule for sleep/waking, body temperature, and hunger
- external zeitgebers (zeit means “time” and geber means “to give” in German)
examples of zeitgebers
- light: exposure to the rising sun resets internal biological clocks to the correct time
- eating patterns
circadian desynchrony
a condition that occurs when the body’s internal rhythms are out of sync with the daily light-dark cycle; can lead to poor sleep, problems with alertness, and is a risk factor for major diseases
the effect of technology on circadian rhythms
artificial lighting from devices breaks down melatonin and affects sleep; children and adolescents who spend more time on screens sleep fewer hours
disruptions to circadian rhythms
- working around the clock/graveyard shifts (e.g. hospital and public safety jobs) can lead to maladaptation syndrome, characterized by health, personality, mood, and interpersonal problems
- when time zones are crossed (it is worst when travelling eastward), jet lag symptoms produce (i.e. fatigue, irritability, and sleepiness)
- daylight saving time is an abrupt change to our daily schedules (especially the setting of clocks forward one hour in the spring)
- 4-6% of the population experience major depressive disorder with seasonal pattern; a mood disorder in which depression occurs regularly at the same time each year, usually during the winter months when less light is available
individual variations in circadian rhythms
- chronotypes are an individual’s natural tendency concerning preferred time to sleep and when they feel most energetic throughout the day
- most people during adolescence and young adulthood show more nocturnal traits, whereas older adults prefer to be active in the morning
the three patterns of waking activity described using EEG recordings
- alpha waves are a waveform of 9-12 cycles/second that usually indicates relaxed waking
- beta waves are a waveform of 15-30 cycles/second that usually indicates alert waking
- gamma waves are a waveform of > 30 cycles/second that usually indicates attention to sensory input
daydreaming (a.k.a. mind wandering)
- spontaneous, subjective experiences in a no-task, no-stimulus, no-response situation; is correlated with activity in the default mode network (DMN)
- is most closely correlated with alpha waves
- are often social in nature, involving imagined interactions with other people
the amount of time in our lives we spend sleeping
1/3 of our lives are spent asleep
two types of sleep
- rapid eye movement (REM) sleep: the components of sleep characterized by waveforms resembling waking, accompanied by rapid eye motion, muscular paralysis, and sympathetic nervous system activation
- non-rapid eye movement (N-REM) sleep: the components of sleep characterized by theta and delta wave activity, and deep physical relaxation
four stages of N-REM
Stage 1: When we first go to sleep, theta waves are observed in the EEG, a waveform of 4-7 cycles/second.
Stage 2: After 10-15 minutes, the person is fully asleep. Heart rate and muscle tension are reduced, and the EEG begins to show K complexes and sleep spindles; waveforms that reflect the brain’s efforts to keep us asleep while continuing to monitor the external environment (we sleep through familiar stimuli).
Stages 3-4: After 15 more minutes, delta waves are observed in the EEG, a waveform of 1-4 cycles/second, that is more prevalent in stage 4. Awakening from stage 4 is difficult, and induces considerable disorientation before the person is fully awake.
paradoxical sleep
the first episode of REM sleep that occurs 90-120 minutes after the onset of sleep
- the EEG shows activity similar to waking activity
- the eyes make periodic back and forth movements
- the sympathetic nervous system becomes very active; heart rate, blood pressure, and breathing become rapid of irregular
- males experience erections; females experience increased vaginal blood flow
- when awakened in this states, most people report vivid dreams
REM sleep paralysis
major postural muscles are inactive during REM sleep as a protective mechanism to prevent people from acting out of your dreams
REM sleep behaviour disorder
a condition in which postural muscles are active during REM sleep, resulting in people injuring themselves or their sleeping partners
timing of sleepwalking and sleeptalking
- sleepwalking occurs in stages 3-4 of N-REM sleep
- sleep talking is most common during lighter stages of N-REM sleep, but may also occur during REM sleep
both phenomena become less common with age
sleep cycles
the cycling of REM and N-REM sleep in humans follow a pattern over an eight hour period
- The first four hours of sleep are characterized by longer periods of N-REM sleep (especially stages 3-4) and briefer periods of REM sleep.
- The last four hours of sleep are characteried by longer periods of REM sleep and briefer periods of N-REM sleep (stages 3-4 become less common or virtually absent).
- The last half hour of sleep is in REM sleep (we often wake up with the awareness that we have been dreaming).
benefits of sleep
- plays an important role in growth and repair of the body
- human growth hormone released during stages 3-4 of N-REM sleep
- during N-REM sleep, memories are reactivated and stored in long-term memory
- during REM sleep, newly transformed memories are stabilized
consequences of sleep deprivation
- obesity
- risk for type 2 diabetes
- poor memory performance
- poor reaction time (staying awake for 17-19 hours straight produces worse reaction time than being legally drunk)
- muscle and joint pain
REM rebound
after being sleep deprived, people spend an unusually large amount of their sleep time in REM sleep to make up for it
possible functions of REM sleep
- wires the developing brain; infants spend greater amount of their sleep in REM sleep than adults
- interwoven with mood; individuals with bipolar disorder experience a low need for sleep
this person argued that the unconscious mind expressed itself symbolically through dreams
Sigmund Freud (1900/1953)
two views about dreams
- the activation-synthesis theory of dreaming: the content of dreams reflects ongoing neural activity (e.g. dreams of being unable to move mirrors muscle paralysis during the REM state)
- the dream continuum: dreaming behaviour correlates with activity in circuits that overlap with the DMN; daydreaming and dreaming during sleep are on a continuum, due to simultaneous changes in brainstem activity resulting in lower sensitivity to outside stimuli and a loss of self-awareness and logical thought
nightmares
unpleasant dreams that occur during REM sleep
sleep terrors
- occurs when the usually smooth transition from stage 4 N-REM sleep to REM sleep goes awry; the sleeper becomes very distressed dispite being asleep
- if awakened, the person shows disorientation and confusion
- there is usually no memory of the sleep terror
two types of insomnia
- onset insomnia is the inability to go to sleep
- maintenance insomnia is when sleep is frequently interrupted, or the person wakes up earlier than intended
narcolepsy
- consists of “sleep attacks”, in which REM sleep occurs during wakefulness
- cataplexy is a symptom in which the muscle paralysis normally associated with REM sleep occurs during wakefulness, without loss of consciousness; simply touching the person is enough to end the paralysis
- cells in the hypothalamus that normally secrete orexins are missing or damaged
sleep apnea
- breathing can stop for a minute or two during sleep; the sleeper awakens abruptly gasping for air
- increases the risk for heart disease
- occurs mostly in people who are obese and who snore
sudden infant death syndrome (SIDS)
approximately 1/3,000 Canadian live births result in a SIDS mortality, in which an otherwise healthy infant unexplainably dies while asleep
restless legs syndrome (RLS)
occurs when one of a person’s limbs, usually a leg, experiences a tingling feeling and moves at regular intervals
the disruption in normal logical decision-making that drives addiction is due to distortion in one or more of these three related neural systems
- an impulsive system involving dopamine pathways connecting the midbrain and the basal ganglia
- a reflective system in the frontal lobes that weigh the pros and the cons of a decision, and controls impulses
- the craving system involving the insula
cannabis
- a psychoactive drug that produces excitation, vivid imagery, mild euphoria, depression, social withdrawal, and hallucinations at higher doses
- contains more than 50 cannabinoids (psychoactive compounds), including THC and anandamide
LSD
a psychoactive drug that interacts with serotonin receptors to produce hallucinations
caffeine
- a stimulant found in coffee, teas, cocoa products, soft drinks, energy drinks, and over-the-counter pain relievers that inhibits adenosine
- produces a withdrawal syndrome characterized by headaches and fatigue
nicotine
a stimulant that mimics the action of acetylcholine; increasing heart rate and blood pressure, reducing fatigue, improving cognitive performance, and producing muscular relaxation
cocaine and amphetamines
- psychoactive drugs that produce alertness, elevated mood, confidence, a sense of well-being, and schizophrenic-like symptoms at higher doses (e.g. hallucinations, delusional fears)
- cocaine blocks dopamine transporters, keeping all previously released dopamine active, whereas methamphetamine mimics dopamine, leading it to be moved out of the cell
- due to their direct actions on the dopamine reward systems in the brain, these drugs are the most addictive
Ritalin and Adderall
- psychoactive drugs that boost the activity of dopamine and norepinephrine, allowing users to stay alert and concentrate
- misuse can lead to psychosis, heart troubles, and sudden death
- used to treat children with ADHD
ecstasy
- a psychoactive drug that increases heart rate, blood pressure, body temperature, and sociability by stimulating the activity of serotonin and oxytocin
- side effects include dehydration, exhaustion, hyperthermia, convulsions, and death
alcohol
- a psychoactive drug that depresses brain activity and releases dopamine
- at low doses, blood vessels dilate, giving people a warm, flushed feeling
- at higher doses, symptoms include aggression, risky behaviours, and poor motor coordination
- at very high doses, alcohol can produce coma and death
opioids
- psychoactive drugs including morphine, codeine, and heroin that release large amounts of dopamine, leading to feelings of well-being and reduction of pain
- at low doses (i.e. medical practice), opioids produce a sense of euphoria, pain relief, reduced anxiety, muscle relaxation, and sleep
- at higher doses, consciousness is affected by producing a strong, rapid onset of euphoria (a “rush”)
- at very high doses, breathing slows down a lot, occassionally leading to death
non-drug methods for altering consciousness
- hypnosis: an altered state of consciousness characterized by relaxation and increased suggestibility
- meditation: a voluntary alteration of consciousness characterized by positive emotion and absence of thought
- environmental conditions: exposure to high altitudes, starvation, sleep deprivation, sensory deprivation, twirling, and rhythm-induced trance may lead to hallucination, and consistent changes in cognition and emotion
the Stroop test and hypnosis
In the test, participants are asked to respond to the colours of the letters they are shown. When the ink colour matched the word, the reaction time was significantly faster than when they didn’t. Nearly everyone who can read shows a strong “Stroop effect”, in which a well-practised skill (reading) takes precedence over a less practiced skill (naming the colours of letters). However, hynoptized participants who were told that they were reading nonsense words instead of real words didn’t show a Stroop effect; their reaction time was the same no matter what.
