Consciousness - Chapter 6 Flashcards
The Biology of Sleep
CIRCADIAN RHYTHM
A term for changes that occur on a roughly 24hr basis in many of our biological processes, including hormone release, brainwaves, body temp, and drowsiness
- Sleep regulated by a specific part of the hypothalamus is called the SUPRACHIASMATIC NUCLEUS (SCN)
- SCN signals the PINEAL GLAN to release MELATONIN
-Hormone MELATONIN is important for the regulation of people biological clock.
(Can be used to reduce jet lag if the timing of the dose is correct)
Amount of Sleep
Most people need about 7-8 hrs of sleep
-Rare genetic mutation in DEC2 can cause a person to need less sleep
College students need about 9 hr of sleep
-Otherwise naps may result
SLEEP DEPRIVATION
Involves missing a period of restful sleep over one or more days
-Accumulated sleep loss is known as SLEEP DEBT
Stages of Sleep
STAGE 1
- Brief transitional stage of light sleep. Lasts 1-10 Min
- Changes from alpha/beta waves (during wakefulness) to theta waves (when you fall asleep)
- Hypnic/myoclonic jerks and hypnagogic imagery occur
STAGE 2
- 10 to 25 min
- Sleep spindles and k-complexes
- As brain waves decelerate, heart rate slows, body temp decreases, muscles relax even more, and eye movements cease
STAGES 3-4
- Enter into this after 10-30 min
- Called “slow-wave” sleep. Very deep sleep bc of DELTA WAVES
- Important for us to feel rested
STAGE 5
-Characterized by REM SLEEP
-20 to 25% of our nights sleep
-Cycles of REM last between 20 min - 1 hr
(Your body slowly starts to regress, 4,3,2,5 BUT NEVER GOES BACK TO STAGE 1)
Difference between 3 and 4 is how much you spend in the DELTA WAVE activity. For every hour that adults spend in sleep they stay more in stage 3 and 4.
AWAKE: Beta Waves
RELAXED: Alpha Waves
REM sleep
We dream during most stages of sleep
Most of our dreaming occurs during REM sleep
- REM dreams are often emotional, illogical, and prone to sudden shifts in “plot”
- Non REM dreams are shorter, more thought-like and repetitive, and deal with everyday topic of current concern to us
Our eyes dart around during REM sleep
Middle ear muscle activity (MEMA) also occurs during REM
-Bodies are paralyzed during REM sleep
Dreaming
LUCID DREAMING
The experience of becoming aware that you are dreaming while asleep
Dolphins and ducks sleep with half of their brains turned off so they are aware of possible threats
Why we dream?
Scientists don’t know why exactly, some posib. are…
Help us process emotional memories
Learn new strategies or ways of doing things
Theories of Dreaming
- Dreaming is a near universal experience
- When awaked during REM, people report vivid dreaming
- Blind people dream
- Some constants across cultures in dream content
- Content of dreams also differ across sex and culture too
FREUDS DREAM PROTECTION THEORY
- Described dreams as the guardians of sleep
- During sleep, the ego, which acts as a sort of mental censor, is less able than when awake to keep sexual and aggressive instincts at bay by repressing them
- If not for dreams, these instincts would bubble up, disturbing sleep
- the DREAM-WORK disguises and contains the pesky sexual and aggressive impulses by transforming them into symbols that represent WISH FULFILLMENT (how we wish things could be)
ACTIVATION-SYNTHESIS THEORY
- AST proposes that dreams reflect brain activation in sleep, rather than a repressed unconscious wish
- Throughout the day and night, the balance of neurotransmitters in the brain shifts continually
- The process of these shifts during the night activates/depresses different brain areas, leading to a haphazard and chaotic pattern of neural firing
- This firing is then translated by the forebrain as effectively as possible (sometimes leading to strange and disordered experiences during dreams)
Disorders of Sleep
30-50% of people report some sort of sleep problem
INSOMNIA
- Most common
- 9-15% of people have long-standing problems
1. People falling sleep, usually taking more than 30 min
2. Waking up too early in the morning
3. Waking up during the night and not being able to fall back asleep - Going to bed habits help, as well as pills and psychotherapy
NARCOLEPSY
-A sleep disorder in which people experience episodes of sudden sleep
(Cataplexy (complete loss of muscle tone))
-Causes include genetic factors, brain damage, and lack of hormone OREXIN
-Drug MODAFINIL is treatment
SLEEP APNEA
- Disorder caused by a blockage of the airway during sleep, resulting in daytime fatigue
- Struggling to breath causes a person to rouse from deeper levels of sleep
- Struggling for breath can occur 100, 1000s of times per night
- Treatment depends on the cause. Weight Loss can help, and surgically remove tonsils in children
- Alternatively, a CPAP machine can be worn during the night
NIGHT TERRORS
- Sudden waking episodes characterized by screaming, perspiring, and confusion, followed by a return to deep sleep
- Occurs mainly in children
- Lasts a few min
SLEEP WALKING
- 15 30% of children and 4 to 5% of adults sleepwalk occasionally
- People deprived of sleep are more likely to exhibit sleepwalking when they do fall asleep
Hallucinations
Are realistic perceptual experiences in the absence of external stimuli
Common misconception that hallucinations occur only in psychologically disturbed people. They are more common than that
Out-of-Body and Near-Death Experiences
Out-of-Body (OBE)
- is a sense of consciousness leaving our body
- About 25% of uni students and 10% of the gen pop report having experienced one or more OBE
- No good scientific evidence that OBEs are a true perceptual experience
Near-Death experience (NDE)
is an OBE reported by people who’ve nearly died or thought they were going to die
-Classic elements of NDE are people passing through a dark tunnel, experiencing a bright light. or seeing our lives pass before our eyes. Meeting spiritual people or long dead relatives
-No scientific evidence that these are real
Deja Vu
Feeling of reliving an experience that new
The frequency of deja vu experiences tends to decline with age
What causes a deja vu?
- Excess dopamine in the temporal lobes
- Abnormal electrical activity in the right temporal lobe
Mystical Experiences
Feelings of unity or oneness with the world, often with strong spiritual overtones
Experiences reported differ between individuals of different religions
Hypnosis
Set of techniques that provides people with suggestions for alternations in their perceptions, thoughts, feelings, and behaviours
Based on standardized scales, scientists have established that
- 15 20 % of ppl are “highly suggestibles”
- 60 70% of ppl are “medium suggestibles”
- 15 20% of people are “low suggestibles”
Hypnosis has a wide range of clinical applications for high and medium suggestibles
Myths regarding hypnosis
6 Myths
- Hypnosis produces a trance state in which “amazing” things can happen
- Hyp. phenomena are unique
- Hyp. is a sleeplike state
- Hypnotized people are unaware of their surroundings
- Hypnotized people forget what happened during hypnosis
- Hyp. enhances memory
Theories of Hypnosis
SOCIAL-COGNITIVE THEORY
an approach to explaining hypnosis based on people attitudes, beliefs, and expectations
- Peoples expectations of whether theyll respond to hypnotic suggestions are correlated ith how they respond
- Theory holds that attitudes, beliefs, and motivations influence people’s suggestibility
DISSOCIATION THEORY
is an approach to explaining hypnosis based on a separation between personality functions that are normally well integrated
- When hypnotized, part of the mind is subject to suggestion, but other parts (known as hidden observers) remain awake/aware
- More modern research has suggested that observer is actually a “flexible observer”
Psychoactive drugs
contain chemicals similar to those found naturally in our brains and that their molecules alter consciousness by changing chemical processes in Neuron’s
-While the chemical properties of drugs can change their effects, ones MENTAL SET, or beliefs and expectancies about the effects of the drugs, can also influence their effect
Substance Abuse vs Dependence
People qualify for a diagnosis of SUBSTANCE ABUSE when they experience recurrent problems associate with the drug
SUBSTANCE DEPENDENCE is a more serious pattern of use, leading to clinically significant impairment, distress, or both
-TOLERANCE is a key feature in dependence. Occurs when people need to consume an increased amount of a drug to achieve its intoxication
Depressants
Alcohol and sedative-hypnotics (barbiturates and benzodiazepines) are depressant drugs
- depress the effects of the CNS
- Sedative means “calming”, hypnotic means “sleep inducing”
What is Consciousness?
the awareness of internal and external stimuli. It is our subjective awareness of the world and ourselves.
Alcohol (Depressant)
Most widely used and abused drug
Small doses of alcohol can promote feelings of relaxation, elevate mood, increase talkativeness and activity, lower inhibitions, and impair judgement
Larder doses, when blood alcohol content (BAC) reaches .05 to .10, the sedating and depressant effects of alcohol generally become more apparent
-Brain centres become depressed, slowly thinking and impairing concentration, walking and muscular coordination
Short term effects are directly related w BAC
Women absorb alcohol faster than men, leading to a higher BAC when other factors are controlled
Hypnotics (Sedative)
Used for treatment of acute anxiety and insomnia
Dangerous at high doses because of their strong depressant effects. Can produce unconsciousness, coma, even death
THREE CATEGORIES
- Barbiturates (Nembutal, secondal)
- Non-barbiturates (Sopor, qualaludes)
- Benzodiazepines (Valium, Xanax)
Stimulants
They rev up your CNS
Popular ones are…
NICOTINE
-An addictive drug
- Activates receptors sensitive to the neurotransmitter ACETYLCHOLINE. Smokers often report feelings of stimulation as well as relaxation and alertness.
- Has ADJUSTIVE VALUE - it can enhance positive emotional reactions and minimize negative emotional reactions
COCAINE
Cocaine is the most powerful natural stimulant
Users report euphoria, enhanced mental and physical capacity, stimulation, decrease in hunger, indifference to pain, sense of well-being and diminished
-These feelings usually peak quickly and fade within 30 min
Cocaine increases the activity of the neurotransmitters DOPAMINE and perhaps SEROTONIN
AMPHETAMINES
Different patterns of use can produce different effects
1: occasional legal use
2. Legal use and dependence
3. Street-drug use and dependence
Narcotics
OPIATES, often called narcotics, relieve pain and induce sleep
HEROINE conveys a sense of euphoria. The pleasurable effects are limited to 3 4hr that the dose lasts
-If a person is addicted to heroine and don’t take the needed doses, they suffer from HEROINE WITHRAW SYNDROME
Psychedelics / Hallucinogens
LSD, mescaline, PCP, Exstasy are hallucinogenic (or psychedelic) because they produce dramatic alterations in perception, mood, and thought
Some researchers classify marijuana as a mild hallucinogen as well
Marijuana
Most freq. used drug in Canada
Effects of pot are produced by THC
Users report sense of time slowing down, enhanced sensations of touch, increased appreciation for sounds, hunger, feelings of well-being, and a tendency to giggle
Higher doses, symptoms much more unpleasant
Can last for 2 to 3 hrs
Although pot produces more damage to cells than tobacco smoke, scientists haven’t found consistent evidence for serious physical health or fertility consequences from marijuana use
Chronic use can impair attention and memory
LSD and other Hallucinogens
LSD
Acid is a common hallucinogen
-Approx 11% of Canadians have tried LSD
-Interferes with serotonin at the synapse
-Associated with areas of the brain rich in receptors for the neurotransmitter dopamine
Small amounts of LSD can produce dramatic shifts in our perceptions and consciousness
- Clearing of thoughts, changes in sensations and perceptions, and mythical experiences common
- Can also produce panic, paranoia, confusion, depression, and bodily discomfort
OTHER HALLUCINOGENS
Ecstasy (MDMA) has a stimulant and hallucinogic properties
Produces cascades of the neurotransmitter serotonin in the brain
Side effects include
- High blood pressure
- liver problems
- memory loss and damage to neurons that rely on serotonin
- depression
