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?