the brain and consciousness consciousness: awareness of ourselves and environment cognitive...
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The Brain and Consciousness
• Consciousness: awareness of ourselves and environment
• Cognitive neuroscience: interdisciplinary study of brain activity with cognition (perception, thinking, memory, language)
• Broca and Wernicke: Language Centers • http://www.learner.org/resources/series142.html#
Dual Processing• If we discuss the biology – where do ideas of the
spirit, conscience, emotion, etc come from?– Conscious left vs. intuitive right– Older brain keeps us alive– Unconscious priming on conscious (explicit) or
unconscious (implicit) memories– Automatic prejudice (unintentional microaggressions)
• Principle that information is simultaneously on conscious and unconscious tracks within the brain/mind
The Two-Track Mind
• Parallel tracks– Visual perception track enables us to create the
world around us– Visual action track guides our moment to
moment actions
What happens when they conflict with each other?
• The Hollow Face Illusion:– http://www.youtube.com/watch?v=Rc6LRxjqzkA– How is this happening?
• Serial conscious processing: slower than parallel processing, but skilled at solving new problems that require attention
So why do we have this parallel process?
• Simply – to keep us from doing everything at once– Abnormal vs. normal
Sleep as a State of Consciousness
• Even when you are deeply asleep, your perceptual window is not completely shut
–What is our evidence of this?
Biological Rhythms and Sleep
• Circadian Rhythm• Body temp rises, peaks, dips, and drops• Thinking is sharpest at peak
• Why is pulling an all-nighter a TERRIBLE idea?
So what’s going on here…• Suprachiasmatic nucleus (SCN) in hypothalamus
– Causes pineal gland to decrease production of melatonin• Pineal gland increases melatonin at night and decreases it during the
day as directed by SCN – Why?
1. Bright light tweaks circadian clock activating light sensitive retinal proteins SCN Pineal Gland Melatonin (increase/decrease by need)
• So why is falling asleep to TV/computer screen/tablet screen a terrible idea?
What has caused us to stay up later and force ourselves awake in the morning?
Sleep Stages
• Considered different state of consciousness because different parts of brain’s cortex stop communicating – While others start communicating
• Still-active sleeping brain has its own biological rhythm
• Which brain scan is used most in sleep studies?
Why do you yawn?
• Is it actually contagious?• Which nervous system is at use when you
yawn?• How is this related to a shiver?
Sleep• Need for sleep varies with
individuals– 20 hours for infants– Roughly 8 for those between– 6 hours for adults in their
70’s
Stage 0: A person is relaxed with eyes closed…
• EEG shows alpha waves– You are not asleep yet
Quiet Sleep: NREM sleep• Stage 1 lasts from 30 secs to 10 min
– “falling asleep” called hypnagogic state• Lucid dreaming
– “waking” period is called hypnopompic state– just ten more minutes…
– Characterized by sensory images and slow rolling eye movements
– Appearance of theta waves on EEG (mixed with alpha)– May experience hallucinations
• Sensation of falling• Most alien abductions happen here
Quiet Sleep cont’d
• Stage 2 lasts 20 minutes – theta waves, sleep spindles, and K-complexes on EEG– Sleep spindles: bursts of rapid, rhythmic brain wave
activity– Sleep talking occurs most here– You are now full on asleep
Quiet Sleep cont’d
• Stage 3– Transition to stage 4– Recognized by the beginning of delta waves on
EEG
Quiet Sleep cont’d• Stage 4
– Deep sleep, night terrors, sleep walking– Lasts 30 min, recognized by 20-50% delta waves in
EEG
**AMOUNT OF TIME SPENT ON STAGES 3 AND 4 VARIES AS NIGHT PROGRESSES**
Active Sleep: REM Sleep (technically stage 5, but not referred to as stage 5)
• Nearly all dreams occur in REM– Dreams are more vivid and story-like than in earlier stages
• REM increases during the night– Less than a minute to over an hour– 25% of the night’s sleep
• Causes atonia which is temporary paralysis of the body
• Brain is active while body shows loss of muscle tone
During REM Sleep
• Heart rate rises• Breathing becomes rapid and irregular• Eyes dart around• Genitals become aroused
– Erections/vaginal lubrication and clitoral engorgement (not dependent on sexual nature of dream)
– Men’s erection upon waking stems from the night’s last REM
– Typical 25 year old male erections happen for half the night
REM Sleep
How are you “active” yet not…
• Brain’s motor cortex is running…• Brainstem blocks the messages
– Muscles relaxed (essentially paralyzed)• REM is called paradoxal sleep
– Internally aroused, externally calm
• So, how is it that arousal happens when we sleep?
Sleep Cycle
• Repeats about every 90 minutes• Night progresses, deep stage 4 gets briefer
and disappears– REM and stage 2 get longer
• By morning, 20 to 25% has been REM– Everyone dreams, we don’t remember most of
what we dream
Why do we sleep?
• Without sleep our bodies deteriorate– Functionality/productivity– Aging– Weight gain and metabolism– Suppress immune cells (infections/cancer)– Memory impairment
Wait… hold up… you said weight gain?
• Sleep deprivations increases hunger-arousing hormone – ghrelin – and decreases hunger-suppressing hormone – leptin– Increases appetite and eating – Also increases stress hormone – cortisol
Sleep Disorders• Insomnia• Narcolepsy
• Lacking Orexin • and hypothalamic links
http://www.youtube.com/watch?v=-zVCYdrw-1o
• Apnea• Parasomnias
– SIDS– Jet lag– Sleepwalking (Somnambulism)– Bruxism
Dream Theories
• Theoretically based• Freud and driven unconscious
1. Freud’s wish-fulfillment
• Psychic safety valve– Safe place to express unacceptable
feelings– Hidden meanings
– On The Interpretation of Dreams• Manifest content – remembered part
of dream• Latent content – underlying meaning
of dream
2. Information-processing
• help sort day’s events and consolidate our memories– That story about the place with the guy that did
the stuff… oh crap I lost it…
– Where else have we discussed information processing?
3. Physiological function
• Brain stimulation during REM = develop and preserve neural pathways
4. Activation-synthesis
• REM triggers neural activity to evoke random memories which our brain weaves into stories– Ever had a dream about the first house you lived
in or a childhood occurrence?– Ever had a dream with people from your past
interacting with people from your present?
5. Cognitive development
• Dreams reflect individual’s knowledge and understanding of the world around them– Some take it WAY to seriously
NOT MAUTHE
HYPNOSIS
Can anyone experience hypnosis?• Yes!
– Well, sort of – it’s called suggestion• Hypnotic suggestion
Can hypnosis be therapeutic?
• Maybe kinda sorta not really but in only in some cases…
– Posthypnotic suggestion has been found to alleviate headaches, asthma, stress-related disorders
• How about pain? Sometimes – Hmmmm that’s up for debate.
How does it work?
• Hypnosis is a divided consciousness– According to some or most or any or none
• Dissociation: a split in consciousness which allows some thoughts and behaviors to occur simultaneously with others– Remember selective attention?
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