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”
