【4】States of Consciousness

Consciousness - state of being aware of internal and external stimuli

Sleep - decreased levels of physical activity; reduced sensory awareness

Wakefulness - high sensory awareness, thought, and behavior

Biological rhythms - cycle of bodily change that maintains homeostasis in the body

•  Circadian rhythms -  takes place over 24 hours

Sleep regulation - how the brain switches between sleep and wakefulness

Sleep

• - sleep rebound - when someone falls asleep faster after being sleep deprived; 1 type of homeostatic regulation

• - can be tracked using EEG (electroencephalography) which measures brain waves

• - sleep-wake cycles are controlled by the thalamus, hypothalamus, (for slow wave sleep) and the pons (for REM sleep)
• is regulated by melatonin which is secreted by the pineal gland

• - regulates and secretes hormones eg. melatonin, luteinizing hormone

• - stimulates growth and follicles

Disruptions of Normal Sleep

Jet lag - when a person's internal circadian rhythm and their environment are misaligned

• Symptoms - fatigue, sluggishness, irritability, insomnia (difficulty in falling/staying asleep)

Sleep Debt - leads to decreased levels of alertness and mental efficiency; caused by sleep deprivation

Hypotheses on why we Sleep

Adaptive

• for us to restore resources that were used during the day
• to avoid predators in the dark
• evolutionary pressure
• maintaining healthy weight, decreasing stress, increasing mood, coordination, cognition, and memory formation

Cognitive

• insufficient sleep disrupts cognitive functions
• benefits: improved creative thinking, language, judgement, and processing emotional information
• Sleeping after learning a new task can improve performance

4 Stages of Sleep

• differentiated by brain wave activity
• divided into 2 categories 
• Non-REM sleep - made up of 3 stages
• REM sleep - aka rapid-eye movement sleep; your eyes dart around while your eyes are closed; brain waves are similar to those that are awake

Non-REM

Stage 1 (drifting to sleep)

• heart rate and respiration slows down
• muscles become less tense
• core body temperature drops slightly

• Early - produces alpha waves (8-13 Hz)
• Late -  produces theta waves (4-7 Hz) 

Stage 2 (going into a state of deep relaxation)

• theta waves are produced
• waves are sometimes interrupted by sleep spindles
• Sleep spindles - random bursts of higher frequency brain waves; important for learning and memory
• K-complexes - spikes of high amplitude patterns; also appears as a response to external stimuli

Stage 3 (deep-sleep)

• produces delta waves (less than 3 Hz)
• heart rate and respiration slows down more
• If the person has increased alpha waves during stage 3, the person will not feel refreshed when waking up

Stage 4 (REM Sleep)

• brainwaves become similar to those observed when a person is awake
• when dreams happen
• muscles get paralyzed

Sleep cycles (~90 minutes long)

• An average night has 5 cycles (~7.5 hours)
• As we go though each cycle, stage 3 will shorten and REM sleep lasts longer
• stage 1: 5 mins
• stage 2: 20 mins
• stage 3: 10 mins
• stage 4: 30 mins
• REM rebound - when REM sleep is interrupted

Dreams

Sigmund Freud believed that dreams can give insight for dealing with problems in our unconscious mind

• Manifest content - storyline of a dream
• Latent content - hidden meaning of a dream

Collective unconscious - theoretical repository of information that is shared by everyone; certain symbols in dreams reflect universal ideas with meanings that are similar for all people regardless of culture or location

Problem-solving theory of dreaming - mind tries to solve issues that exist while you're awake while you're unconscious.

Sleep Disorders

• 30-50% of the population experiences some type of sleep disorder in their lifetime

Dyssomnias - abnormalities in the amount, quality, or timing of sleep 

        Insomnia - inability to sleep/can't maintain sleep

        Narcolepsy - inability to stay awake; random periods where a person enters REM 

        sleep for a few minutes; might be caused by irregularity in the production of orexin 

        in the hypothalamus

        Sleep Apnea - repeated stops in breathing while sleeping; associated with obesity 

        and alcohol consumption

                                - people wake up after 1-2 mins of not breathing

                                - SIDS (sudden infant death syndrome) - fatal for babies

        Somnambulism - sleepwalking (+ sleeptalking); does not occur during REM sleep

        Night terrors - screaming, crying, jerky movements while in deep sleep

                               - overlaps with somnambulism; can create motions of being attacked; 

                                  the person who experiences these will not have memories of it

Substance Abuse

dependence - happens when the person keeps using a substance to avoid unpleasant feelings associating with not taking it

                        - caused by not wanting experience withdrawal symptoms

tolerance - over time, more of a substance is needed to get desired effect; doesn't always lead to dependency on that substance

withdrawal - causes symptoms from not taking from not taking a substance someone's dependent on

psychoactive drugs - chemicals that change perceptions and mood; stimulates release of dopamine; 3 types

• depressants - calms down neural activity and slows down body functions

• Ex. alcohol (not a stimulant or disinhibitor though it acts like one)
• brain activity that controls judgement and inhibition slows down
• the urges you would feel while sober are more likely to be acted upon when drunk
• alcoholism - alcohol -> tolerance -> withdrawal -> problematic use; can cause brain shrinkage
• women have less digestive enzymes for alcohol than men
• consequences: impaired judgement, alcohol poisoning, blackouts, lowered self-awareness/zoning out, slowed nerve regeneration, nerve death
• expectancy effects - believing in the effects of alcohol can cause us to act in ways we believe we would when drunk; expectation of its effects influence behavior

• barbiturates (tranquilizers) - commonly used as sleep and anti-anxiety meds
• this plus alcohol results in a lethal depressant 
• consequences - lowered nervous system activity, memory and judgement

• opiates - (opium/narcotics) - depress neural activity, reduces pain and anxiety
• Ex. morphine, heroine, codeine, methadone
• Side effects: increased feelings of pleasure, constricting of pupils, slowed breathing, lethargy
• Repeated use can cause the brain to stop producing endorphins and withdrawal symptoms are intense can lead to an overdose (lethal)

• stimulants - excite neural activity and speeds up functions
• addiction causes a crash when withdrawal sets in
• Side effects: pupils dilate, breathing rate increases, blood sugar levels rise, reduced appetite, increase in energy and self-confidence
• Ex. caffeine, nicotine, cocaine, methamphetamine, amphetamine, ecstasy

• nicotine - in tobacco
• E-cigs - can make regular smoking more addictive + toxic chemicals; does NOT help people quit smoking
• 1/7 smokers who try to stop, will.
• Withdrawal symptoms - craving, insomnia, anxiety, irritability, distractibility

• cocaine - stimulant that temporarily increases alertness and a euphoria rush (depletes brain's supply of NT, dopamine, serotonin, and norepinephrine)
• After 1 hour of taking, a crash occurs; increase in agitation and depression when drug wears off
• Effects of cocaine are dependent on dosage and the user's expectations of taking it

• Amphetamine -  speeds up neural activity, body functions; causes mood changes
• Methamphetamine - stronger variant; reduces base levels of dopamine over time

• hallucinogens - psychedelic; distort perceptions, make up sensory images
• visual cortex and emotional centers are stimulated
• hallucinations range from simple shapes to dream-like experiences
• creates symptoms similar to near death experience
• seeing a bright light, replaying old memories, out of body experiences
• Ex. synthetic (LSD, ecstasy) or natural (marijuana)

• Ecstasy - synthetic halllucinogen that blocks serotonin reuptake which produces feelings of euphoria and social intimacy 
• Side effects: dehydration, increased blood pressure, decreased sleep, immunity, and memory
• LSD - aka acid; causes feelings of euphoria, detachment, and panic
• user's mood and expectations can affect experience
• Marijuana - contains THC; heightened sensitivity to colors, sounds, tastes, and smells
• ranges from producing a relaxing effect to a euphoric high
• impairs motor and coordination skills
• Side effects: agitation, psychosis, chronic bronchitis, social anxiety, suicidal thoughts, depression, impaired memory

Altered States of Consciousness

hypnosis - makes a person relax and open to suggestion; might experience seeing things that aren't there; able to unlock repressed memories

        posthypnotic suggestion - instructions given to hypnotized people after they wake 

        up

• Neodissociative theory - hypnosis splits the mind into 2 parts
• 1st part obeys the hypnotist
• 2nd parts acts as a hidden observer

meditation - techniques that train attention

        MSBR (mindfulness-based stress reduction) - tool used in medical settings to help 

        alleviate stress, pain and anxiety; increases alpha and theta brain wave activity