Post on 16-Dec-2015
transcript
What is consciousness?
Consciousness is the awareness of ourselves and our environments
Attentional spotlight: what are you focusing on (foot, breathing)
Studying consciousness
In the early days of psychology, consciousness was considered the main substance of psychology (just like life to biology, matter and energy to physics)
Because it could not be observed, psychology focused on behavior Mental concepts began to reenter psychology in 60s and
70s with renewed emphasis on cognitive psychology and neuroscience (also access to computers to model mental processes)
Subconsciousness
Much brain activity occurs outside of our awareness parallel processing
For example we are not conscious of brain processing color, depth, motion, and form all at the same time
Well-learned tasks require little conscious attention, we can do them automatically (riding a bike)
Conscious awareness
Mental activity that we are aware of Serial Processing: Attend to one thing at
a time
enables us to exert voluntary control and communicate our mental states to others
keeps us from doing and thinking everything at once
novel tasks require conscious attention
Daydreams and fantasies
nearly everyone has daydreams or fantasies every day daydream (re-live, embellish previous
experiences) fantasy (imagine novel experiences)
young adults spend more time daydreaming than older adults
Functions of daydreams
Help young people explore and develop identities; feeds social and cognitive development TV, video games, fast-food jobs reduce
opportunities to daydream & fantasies Enhance creativity
Scientists, artists, writers the shape of the double helix of DNA occurred to
Crick during a daydream while he was sick in bed with a cold
Substitute for impulsive behavior delinquents have fewer daydreams
Fantasy-prone personality
spend half of their time daydreaminghave trouble distinguishing
memories of imagined events from those of actual experience
Circadian rhythms
Our bodies synchronize with the 24-hour cycle of the day and night through a biological clock called circadian rhythm
Body temp. rises in morning, peaks during day, dips in early afternoon
Thinking sharpest and memory most accurate when people are at their daily peak in circadian arousal for adults, usually in morning; for young adults, usually in
evening results of study on circadian rhythms and problem solving
Stages of sleep
awake, relaxed (meditating)--alpha waves
stage 1 (2 minutes) light sleep sensation of falling or floating (hypnogogic sensations),
sudden jerk
stage 2 (next 20 minutes) sleep spindles (bursts of rapid, rhythmic brain wave activity)
stage 3 transitional stage to deep sleep (several minutes) beginning of delta waves
stage 4 (about 30 minutes) deep sleep,very hard to awaken (except to name,
baby's cry) at end of deep sleep is when children tend to wet the
bed or sleepwalk “sleep like a baby"--infants and children
REM sleep after an hour of sleep, you pass back through stage 3
and 2 sleep and enter REM sleep for about 10 minutes.
Characteristics of REM sleep
Paradoxical sleep: internally, body is aroused, but externally appears calm (brainstem blocks messages from active motor cortex, leaving muscles relaxed)
increased heart rate rapid breathing genital arousal beginning of dreams muscle twitches (watch dogs dreaming) relaxed muscles
Dreams and REM sleep
If people are awakened during REM sleep 80% of the time, they will recall dream even people who say the "never dream" REM dreams are emotional and story like
Eye movement, why does it occur? watching dream "movies” overflow of dreamer's active nervous system
The sleep cycle
sleep cycle repeats itself about every 90 minutes
stage 4 sleep gets briefer and disappears
20-25% of night's sleep is in REM sleep
Why do we sleep?
We spend about one third of our life sleeping 1. to rest: so we will not feel tired the next day
lowered body temp. conserves energy for daytime hours
2. ecological niche (stay immobile during night, out of harm's way)Paradox with children (why they do not want to
go to bed?) (most vulnerable to harm)Symon's theory: dreams are visual, not vocal or
olfactory--thus, we could sill be awakened by creatures with harmful intent or who needed help
3. Helps us recuperate restores body tissues ("beauty rest"); esp.
brain tissues brain actively repairing and reorganizing itself,
consolidating memories (like defrag program on personal computers)
4. Aids in growth during sleep, pituitary gland releases a growth
hormone (may help to explain why children sleep so much more than adults)
Sleep disorders
Sleep deprivation most adults need 8-10 hrs. sleep per
day (children, more) varies with agegenetic dispositions
with less than 7 hours, most people show signs of sleep deprivation
causes of sleep deprivationmodern life (TV, lights, shift work)
effects of sleep loss and deprivationsleepiness and general malaiseirritability poor judgmentsincreased accidents (rest requirements for pilots)loss of creativity and lack of concentration(expert performers sleep most, take most naps; also
practice the most)suppression of disease fighting immune systemslowed performance (however, not highly motivating tasks)
Insomnia: problems falling asleep 10-15% of adults complain of insomnia due to excitement or anxiety (for
stressed organism, alertness is normal) best cures: exercise regularly (late
afternoon, not late evening, regular sleeping schedule, relax before bedtime
Narcolepsy: periodic overwhelming sleepiness 1 in 2,000 people suffer from this live with extra caution (e.g., traffic menace)
Sleep apnea: people intermittently stop breathing during sleep
mostly overweight menafter an airless minute or so decreased blood oxygen
arouses the sleeper to awaken and snort in air for few seconds
can occur as much as 400 times a night, depriving person of stage 4 sleep
night terrors sit up talk, appear terrified (but rarely
remember it the next day occur during stage 4 sleep most common with children
not nightmares which occur during REM sleep
Why do we dream?
dreams help us to process information they help sift, sort, and fix into memory our day's
experiencesas we sleep, our bodies are consolidating the days
important memories • following stressful experiences or intense learning
periods, REM sleep increases• memory experiments: if awakened during REM sleep,
people remembered less the next morning what they had learned the previous day
• studies of expert violinists (sleep more (60 [8.6 hrs. day] vs 54 [717] hr.s per week than violin teachers and they nap more 2.8 hrs. per week vs 0.9 hours)
physiological function by providing brain with periodic
stimulation, they help to develop and preserve the brains neural pathwaysinfants, whose neural networks are just
developing, spend a great deal of time in REM sleep
studies of experts (nap more)
dreams spring from the mind's effort to make sense of unrelated, random bursts of neural activity
they are triggered by random bursts of neural activity
all 3 theories may have some validity; may not be mutually exclusive
Need for dreams
Although disagreement on exact function of dreams, scientists agree that we need REM sleep if deprived of REM sleep, we return
more quickly to the REM stages after falling asleep"REM rebound"
Do cats and fish dream?
Cats, yes; fish, noOther mammals experience REM
sleep and REM rebound this suggests that its causes and functions are
deeply biological that mammals (whose behavior involves more
learning than instinct) experience REM and not fish, supports information processing theory of dreams