ECC Chapter 4 Consciousness PSY 100 Fall 2012 9.18.14.pptx

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Objectives for 9/18

• _{Describe the importance of external cues to}

our circadian rhythms.

• _{Identify the stages of sleep.}

• _{Identify the general brain activity associated}

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Consciousness

• _{What is consciousness?}

• _{Take a second to experience your}

consciousness.

• _{How does consciousness help us?}

• _{Is “consciousness” the same thing as “waking}

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Attention

• _{Our ability to focus our awareness and senses}

on particular aspects of stimuli.

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Characteristics of Attention

• _{1. Has limited capacity}

• _{2. Is selective in nature}

• _{3. Can be blind}

• _http

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What about splitting our attention?

• _{Multi-tasking}

– _{Involves a}_{division of attention}

– _{Less similar tasks are less likely to interfere with}

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Clocks and Consciousness

• _{Think about your day, does your consciousness}

change?

• _{How about your ability to focus attention?}

• _{The nature and quality of our consciousness relies}

on numerous biological and environmental

“clocks”.

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Clocks and Consciousness

• _{These are examples of Circadian Rhythms.}

– _{Biological and psychological processes that change}

systematically throughout the day/night.

• _{Many different types of circadian rhythms, not}

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The Body’s Clock

• _{What controls our circadian rhythms?}

• _{Suprachiasmatic Nucleus (SCN)}

• _{Relies on a combination of our biology/psychology}

with the environment.

– _{I.e. as the sun sets, less light enters our eyes to be sent to}

the SCN and visual system.

• _{This triggers the production of Melatonin, which reduces}

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The 24.2 Hour Day

• _{What would happen if we had no external}

time cues (sunlight, clocks, etc…)?

• _{We would eventually drift back to our natural,}

intrinsic, circadian rhythm.

– _{This rhythm is about 24.2 hours}_or_{a little bit}

longer than a day.

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The 24.2 Hour Day

• _{Thus, external cues are}

_extremely

_important

for regulating our synchronized 24 hour day

rhythms.

• _{Ever had jet lag?}

– _{Your body thinks it is a different time than the}

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Sleep

• _{Electroencephalograph (EEG)}

– _{Measures electrical activity on scalp}

– _{Brain waves are patterns in voltage fluctuations}

• _{The brain is active during sleep}

– _{Characteristic patterns of brain waves occur during}

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Sleep

Stages

• _Onset

– _{Short and fast waves are replaced with slow and long} waves.

• _{Non-rapid-eye-movement sleep (NREM)}

– _{Slowed brain activity}

• _{Rapid-eye-movement sleep (REM)}

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The Sleep Cycle

• _{Stage 2 NREM}

– _{Sleep spindles &} K-complexes appear – _{Brain activity slows,}

breathing is more regular

– _{15-20 minutes}

• _{Stage 1 NREM}

– _{Slow alpha and theta brain waves}

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The Sleep Cycle

• _{Stage 3 NREM}

– _{Theta (slow) and delta (very slow) brain waves} – _{Delta waves are >20% brain activity}

– _{15-20 minutes}

• _{Stage 4 NREM}

– _{Delta waves are >50% brain activity} – _{Deep sleep, difficult to waken}

– _{Physiological functions at lowest level} – _Sleepwalking

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The Sleep Cycle

• _{REM sleep}

– _{Brain is highly active}

– _{Short, fast brain waves (“Paradoxical Sleep”)} – _Dreaming

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The Sleep Cycle

• _{Each cycle from Stage 1 NREM to REM takes}

about 90 minutes to complete.

• _{Progressive cycles spend less time in deep}

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The Sleep Cycle

• _{Usually, we have four or more 90 minute cycles}

throughout the night.

• _{As the night progresses, we spend longer in REM}

sleep and less time in NREM.

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Summary

• _{Our circadian rhythms are a result of the}

combination of internal and external factors.

• _{Sleep is divided into multiple stages of sleep:}

– _{Onset, 4 stages of NREM Sleep, REM sleep}

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Question

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Why Do We Sleep

• _{Provides rest to our muscles and body.}

• _{Maintains immune system.}

• _{Enhances learning and memory consolidation.}

• _{Improve brain function.}

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What Happens If We Can’t Sleep?

• _Microsleep

• _{All of the advantages of sleep are decreased}

with lack of sleep.

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What Happens If We Can’t Sleep?

• _{REM Rebound – when deprived of REM sleep}

for long periods, our body gets to REM faster

and spends more time in REM sleep.

• _{NREM Rebound – same as above but with}

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Question

• _{If we have both REM and NREM Rebounds,}

what does this tell us about the importance of

these sleep stages?

– _{We need to experience the full cycle of sleep}

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Sleep Thinking and Dreams

• _{During sleep, dreams are interesting but not}

the most common brain production.

– _{More common is Sleep Thinking.}

• _{NREM sleep, vague and bland ruminations about} real-life events.

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Sleep Thinking and Dreams

• _{Dreams are less common but provide a much}

more vivid sequence of perceptions, thoughts,

and emotions than Sleep Thinking.

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The Significance of Dreams

• _{Psychoanalytic Model (}

_{Sigmund Freud}

₎

– _{Created one of the first theories of dream}

significance.

– _{Suggested that dreams are made up of two parts:}

• _{Manifest Content – The actual images of the dream} themselves.

• _{Latent Content – The disguised meaning of the dream.}

– _{Dreams have important meaning to us beyond}

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The Significance of Dreams

• _{The Activation-Synthesis Model}

– _{Dreaming is our subjective awareness of the}

brain’s internally generated signals during sleep.

– _{This means that brain activity that occurs naturally}

during sleep is causing multiple parts of the brain to be activated, resulting in dream like states.

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The Significance of Dreams

• _{Neurocognitive Model}

– _{Suggests that dreams represent our interest,}

personality, and individual worries.

– _{Gives two reasons for dreams during sleep:}

• _{1. We have no sensory stimuli so we generate our own} sensory data.

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Sleep Disorders

• _Insomnia

– _{(a) Complain about quality or duration of sleep.} – _{(b) Have difficulty going to sleep or staying asleep.} – _{(c) Wake before it is time to get up}

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Sleep Disorders

• _Insomnia

– _{Many causes – generally a result of stress.}

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Sleep Disorders

• _{- Obstructive Sleep Apnea – Sleeper’s airway}

becomes narrowed or blocked, sending signals

to the brain to wake us up.

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Sleep Disorders

• _{Narcolepsy – Overwhelming daytime}

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Sleep Disorders

• _{Sleep Terrors (Night Terrors)}

– _{Generally in the first few hours of sleep (stages 3}

and 4).

– _{Usually a single sensation (i.e. being crushed)}

rather than a whole story like in a dream.

– _{Not necessarily awake even though they are}

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Sleep Disorders

• _{REM Sleep Behavior Disorder}

– _{Failure of the brain to induce muscle paralysis}

during REM sleep leading to the person acting out the dream sequence.

• _{Gets progressively worse once it emerges.}

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Hypnosis

• _{Hypnosis – Cooperative social interaction in}

which the hypnotized person response to

suggestions with changes in perception,

memory, and behavior.

– _{So does this mean that hypnosis is real?}

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Hypnosis

• _{It is easier to understand hypnosis when we}

know the limits of hypnosis:

– _{Can’t be hypnotized against your will.}

– _{Can’t make you perform behaviors that are contrary}

to your moral values.

– _{Can’t make you stronger than your physical}

capabilities or bestow new talents.

• _{(However it}_can_{enhance already existing skills and abilities}

by increasing self-confidence and concentration)

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Hypnosis

• _{So what}

_can

_{hypnosis do?}

– _{Sensory and perceptual change}

• _{I.e. temporary blindness or paralysis (Conversion} Disorder)

– _{Can have an effect on our memory}

• _{Hypnotic Amnesia – inability to remember events} before or during hypnosis

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Hypnosis

• _{Hypnotist acts as a}

_coach

_{to enhance or}

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What are psychoactive drugs?

• _{Chemical substances that alter various aspects}

of consciousness.

• _{Four Categories as we will discuss them:}

– _{Depressants – Inhibit brain activity}

– _{Opiates – Relieve pain, produce euphoria} – _{Stimulants – Increase brain activity}

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Depressants

• _{Decrease the functioning of the central nervous}

system.

– _{Drowsiness, decreased anxiety and inhibitions}

• _{All depressants are potentially physically}

addictive

and

additive

in nature.

• _Types:

– _Alcohol – _Inhalants

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Opiates

• _{Relieve pain and produce feelings of euphoria.}

– _{Includes morphine and codeine, as well as heroin,}

methadone, vicodin, etc…

• _{Alter an individual's reaction to pain by}

reducing the brain’s perception of pain.

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Stimulants

• _{Increases central nervous system functioning.}

• _{All stimulants are at least mildly addicting and}

tend to increase brain activity.

• _Includes:

– _{Caffeine and Nicotine}

• _{Caffeine works by blocking chemicals that signal sleep.}

– _{Amphetamines and Cocaine}

• _{Prolonged use of these can result in}_{stimulant-induced}

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Psychadelic Drugs

• _{Distorts perception, mood, and thinking.} • _Includes:

– _Mescaline

• _{Naturally occuring in the Peyote plant}

– _LSD

• _{Synthetic (1930s)}

– _Marijuana

• _{We have naturally occurring receptor sites for THC, as well as}

a naturally occurring agonist for THC receptors (anandamide).