States of Consciousness

THE PUZZLE OF CONSCIOUSNESS

Characteristics of Consciousness

• Consciousness – our moment-to-moment awareness of ourselves & our environment

• Characteristics of csness– Subjective & private– Dynamic (ever-changing)– Self-reflective & central to our sense of self– Intimately connected with the process of selective

attention: the process that focuses awareness on some stimuli to the exclusion of others

Measuring States of Csness

• Self-report measures• Behavioral measures• Physiological measures– EEG– MRI– CT scan

Levels of Csness

• The Freudian viewpoint– Cs mind– Precs mind– Uncs

• repression

• The Cognitive viewpoint– Controlled (cs) processing – the conscious use of

attention & effort– Automatic (uncs) processing – without conscious

awareness or effort• Routine actions• Divided attention – the capacity to attend to & perform

more than one activity at the same time

Unconscious Perception & Influence

• Visual agnosia– prosopagnosia

• Blindsight – blind in part of their visual field yet in special tests respond to stimuli in that field despite reporting that they can’t see those stimuli

• Priming – exposure to a stimulus influences how you subsequently respond to that same or another stimulus

• Emotional uncs

Why Do We Have Csness?

• How does csness help us adapt to and survive in our env’t?– Planning function of csness – csness goes hand-

in-hand with the ability to plan, to reflect upon many possible courses of action & to choose one

– Summarizing function – summary or single mental representation

– Override potentially dangerous behaviors governed by automatic processing

– Deal flexibly with novel situations– Self-awareness + communication

The Neural Basis of Csness

• Multiple brain pathways for visual info processing– Primary visual cortex parietal lobe – uncs

guidance of movement– PVC temporal lobe – cs recognition of objects

Csness as a Global Workspace

• There appears to be no single place in the brain that gives rise to csness.

• A collection of largely separate but interacting info-processing modules that perform tasks

• Csness is a global workspace – represents the unified activity of multiple modules in different areas of the brain

• Subjectively, we experience csness as unitary, rather than as a collection of modules & circuits

CIRCADIAN RHYTHMS: OUR DAILY BIOLOGICAL CLOCKS

Keeping Time: Brain & Env’t

• Suprachiasmatic nuclei (SCN) – a part of the hypothalamus that regulate most circadian rhythms pineal gland – gland that secretes melatonin – a hormone that has a relaxing effect on the body (derived from serotonin)

• Daytime: active SCN neurons reduction of melatonin release raising body temp & alertness

• Night: inactive SCN neurons increase in melatonin levels relaxation & sleepiness

• Day light increases SCN activity (env’t cues)

Early Birds vs Night Owls

• Circadian rhythms influence our tendency to be either a morning person or a night person but cultural factors may also play a role.

Environmental Disruptions of Circadian Rhythms

• Jet lag• Night-shift work• Seasonal affective disorder – cyclic tendency to

become psychologically depressed during certain seasons of the year

• Treatments:– Controlling one’s exposure to light– Oral melatonin– Daily activity regulation

SLEEP AND DREAMING

Circadian Rhythm & Sleep

• Circadian rhythm promotes readiness for sleep but not the regulation of sleep

• Beta waves – high frequency (15-30 cps) but low amplitude brain-wave activity present during awake/alert state

• Alpha waves – 8-12 cps brain wave activity occurring in a relaxed/drowsy state

Stages of Sleep

• Stage 1 – a form of sleep from which you can easily be awakened, theta waves (3.5-7.5 cps) increase during this stage– Dreams, vivid images & sudden body jerks

• Stage 2 – a form of sleep in which there are sleep spindles – periodic 1- to 2-second bursts of brain wave activity (12-15 cps)– More relaxed, slower breathing & heart rate,

occurrence of dream

Stages of Sleep

• Slow wave sleep– Stage 3 – regular appearance of slow and large

delta waves (0.5-2 cps)– Stage 4 – dominance of delta waves– Relaxation, decrease in brain activity, occurrence

of dreams• Completed cycle of stages: 1-2-3-4-3-2

Stages of Sleep

• REM sleep – characterized by rapid eye movements, high arousal & frequent dreaming; REM sleep paralysis (paradoxical sleep) (Eugene Aserinsky & Nathaniel Kleitman, 1953)– Heart rate quickens, rapid & irregular breathing,

brain-wave activity resembles that of active wakefulness, penile erections (men), vaginal lubrication (women), difficulty in contraction of voluntary muscles

– Highly aroused body yet minimal movement

Getting a Night’s Sleep: From Brain to Culture

• Brain– Basal forebrain – regulate falling asleep– Pontine reticular formation – regulate REM sleep– REM Sleep• Intense activity in amygdala – emotional nature of

many REM-sleep dreams• Activity in the primary motor cortex that don’t reach

the limbs• Active association areas near primary visual cortex –

visual dream images• Decreased activity in the prefrontal cortex –

monitoring & organizing mental activities does not occur causing dreams to be illogical & bizarre

Getting a Night’s Sleep: From Brain to Culture

• Culture– Changes in season– Climate– Cultural norms re sleeping (i.e., co-sleeping)

Sleep & Age

• Newborn infants – 16 hrs of sleep, ½ of this is REM sleep

• As people age:– They sleep less– REM sleep decreases dramatically during infancy

& early childhood but remains stable thereafter– Decreased slow-wave sleep

Sleep Deprivation

• Sleep deprivation (short-term total sleep deprivation, long-term total sleep deprivation, partial sleep deprivation) impaired emotional, cognitive & physical functioning

Purpose of Sleep

• Sleep & Bodily Restoration– Restoration model – sleep recharges our run-down

bodies & allows us to recover from physical & mental fatigue

• Sleep as an Evolved Adaptation– Evolutionary/circadian sleep models – emphasize that

sleep’s man purpose is to increase a species’ chances of survival in relation to its environmental demands

• Sleep & Memory Consolidation– Memory consolidation – a gradual process by which

the brain transfers info into long-term memory

Sleep Disorders

• Insomnia – chronic difficulty in falling asleep, staying asleep or experiencing restful sleep– Genetics– Anxiety & depression– Stress– Poor lifestyle habits– Circadian disruptions

• Stimulus control – one of the treatments for insomnia

Sleep Disorders

• Narcolepsy – extreme daytime sleepiness & sudden, uncontrollable sleep attacks– Going right into REM Sleep– Cataplexy

• REM-Sleep Behavior Disorder – loss of muscle tone that causes normal REM sleep paralysis is absent

• Nightmares (REM sleep) & Night Terrors (slow-wave sleep) – dreams that arouse the sleeper to a near-panic state

• Sleep apnea – repeated stoppage and restart of breathing during sleep

Theories on Dreams

• Freud’s Psychoanalytic Theory – main purpose is wish fulfillment – gratification of our uncs desires & needs– Manifest & latent content– Dream work

• Activation-Synthesis Theory – dreams do not serve any particular function & merely a by-product of REM neural activity– Activation component – brain stem bombards higher brain

centers with random neural activity– Synthesis component – interpretation of neural activity

that does not match any external sensory event by the cerebral cortex resulting to perception

Theories on Dreams

• Cognitive Theories– Problem-solving dream models – dreams are not

constrained by reality so they can help us find creative solutions to our problems and ongoing concerns

– Cognitive-process dream theories – propose that dreaming and waking thought are produced by the same mental systems in the brain

Drug-Induced States

• Blood-brain barrier – a special lining of tightly packed cells that lets vital nutrient pass through so neurons can function

How Drugs Facilitate Synaptic Transmission

• Agonist – a drug that increases the activity of a neurotransmitter– Enhance a neuron’s ability to synthesize, store, or

release neurotransmitters– Bind with and stimulate postsynaptic receptor

sites– Make it more difficult for neurotransmitters to be

deactivated, such as inhibiting reuptake.

How Drugs Inhibit Synaptic Transmission

• Antagonist – a drug that inhibits o decreases the action of a neurotransmitter– Reduce a neuron’s ability to synthesize, store, or

release neurotransmitters– Prevent a neurotransmitter from binding with the

postsynaptic neuron, such as by fitting into and blocking the receptor sites on the postsynaptic neuron

Drug Tolerance and Dependence

• Tolerance – decreasing responsivity to a drug• Withdrawal – occurrence of compensatory

responses after discontinued drug use• Substance dependence – a maladaptive

pattern of substance use that causes a person significant distress or substantially impairs a person’s life (drug addiction)– Physiological dependence– Psychological dependence

Effects of Some Psychoactive DrugsClass Typical Effects Risks of High Doses and/or

Chronic UseDEPRESSANTAlcohol (Ethanol)

Barbiturates, tranquilizers

Relaxation, lowered inhibition, impaired physical and psychological functioningReduced tension, impaired reflexes and motor functioning, drowsiness

Disorientation, unconsciousness, possible death at extreme dosesShallow breathing, clammy skin, weak and rapid pulse, coma, possible death

STIMULANTSAmphetamines, cocaine, ecstacy

Increased alertness, pulse, and blood pressure; elevated mood; suppressed appetite; agitation; sleeplessness

Hallucinations, paranoid delusions, convulsions, long-term cognitive impairments, brain damage, possible death

OPIATESOpium, morphine, codeine, heroin

Euphoria, pain relief, drowsiness, impaired motor and psychological functioning

Shallow breathing, convulsions, coma, possible death

HALLUCINOGENSLSD, mescaline, phencyclidine

Hallucinations and visions, distorted time perception, loss of contact with reality, nausea

Psychotic reactions (delusions, paranoia), panic, possible death

MARIJUANA Mild euphoria, relaxation, enhanced sensory experiences, increased appetite, impaired memory and reaction time

Fatigue, anxiety, disorientation, sensory distortions, possible psychotic reactions, exposure to carcinogens

Hypnosis

• Anton Mesmer– Claimed that illness was caused by blockages of an invisible

bodily fluid– Used magnetized objects to cure patients– Animal magnetism mesmerism

• James Braid– Investigated the fact that mesmerized patients often went

into a trance– Mesmerism was a state of “nervous sleep” produced by

concentrated attention– Mesmerism hypnosis

Hypnosis

• A state of heightened suggestibility in which some people are able to experience imagined situation as if they were real.

• Hypnotic induction – the process by which one person (a researcher/hypnotist) leads another person (the subject) into hypnosis

Theories of Hypnosis

• Dissociation theories– View hypnosis as an altered state involving a

division (dissociation) of consciousness• Social-cognitive theories– Propose that hypnotic experiences result from

expectations of people who are motivated to take on the role of being hypnotized