“To : perchance to ” Hamlet Circadian Rhythm - daily cycle of biological changes Exam on Wednesday • 80 point, MC exam. You can come early if you think you need more time • Limited use of names, but you should know what experiments found and conclusions from them • Items will come from lecture and book. You can’t ignore your book if you want a top grade • Things I haven’t covered are in the exam

The ’s Time Keeper A Biological Clock?

Suprachiasmatic Nucleus of the hypothalamus (Circadian rhythm generator) • The SCN controls the sleep-wake cycle in part by regulating the secretion of the hormone melatonin by the pineal gland about 1 to 2 hours before sleep. – Melatonin aids sleep if taken when you are in another time zone, but does not increase tendency to sleep under normal situations since your brain is already doing it. – Hypothalamus also important in other cycles, hibernation, migration, ovulation. • SCN Receives direct input from special set of receptors in retina. • Light darkness changes important in circadian rhythm. Zeitgeber (time giver) stimuli which adjust cycle of SCN. • If you are in another time zone and feel your rhythms are out of kilter go to the beach.

What would happen to your circadian rhythms if you were kept in a cave without light cues to determine when you got up and when you went to to sleep? Would you maintain a 24 hr. rhythm? • Cave experiments. Approximate circadian rhythm 25 hours rather than 24. • Adjust poorly to extremes (18 or 30 hour days). • Gustavus weekend jet lag • Natural cycle helps to explain Changing Work Shift Schedules “Morning” and “evening” persons?

What are you like in the morning? If you wake up easily in the morning and become quickly alert and believe you do your best work in the morning, you are a morning person. Looks to be a developmental phenomena • You may be an evening person when you are young but you move in the direction of becoming a morning person. True for both humans and animals although we don’t know why.

Sleep of Adolescents

Mary Carskadon believes that Adolescents need more sleep • Older adolescents(16-18) report being sleepier than younger • If allowed to sleep freely average 9 hours, 25 minutes • Believes biology sets clock forward an hour and changes release of melatonin, length may be related to growth hormone release. • Historically there has been a change in the time when high school starts. • Edina high school experience in 1997. Move to 8:40 starting time from 7:15. – Fewer behavior problems, illnesses and improved test scores.

Theories for sleep- cycle

Restorative-sleep restores “x”. • We sleep to restore depleted physical reserves depleted • Slow wave sleep or deep sleep increases after physical exertion • Lack of sleep leads to impaired concentration, irritability, and impaired functioning of the immune system Problems • People do not sleep less when inactive • Nothing can be identified that shows change with sleep-Siamese twins • There is no repair process that occurs only when we sleep Evolutionary Theories for Sleep Brain waves (EEG) and Sleep

Survival Beta – Normal waking thought and alert problem solving • We sleep to preserve energy (demands drop 10-25%) • High frequency, low amplitude waves when mentally active (13-24 cps) • We sleep to avoid night dangers. Sleep keeps individual inactive Alpha – deep relaxation, blank mind, meditation during dangerous dark period. • large regular waves of 8-13 cycles when relaxed with eyes closed • We sleep more when we are sick or injured Stages of Sleep • Species differences Predators can afford to sleep more, high Stage 1, Theta – Light sleep calorie meals and little danger. • low amplitude and low frequency waves(4-7 cps) • Some animals are on nocturnal schedules others diurnal Stage 2, Sleep spindles • bursts of high amplitude waves Stage 3 & 4, Delta – deep sleep • low frequency and high amplitude waves (<4 cps) • Probably serves a restorative function. Terminal Stage 1, REM

Rem Sleep

REM Sleep Neurology of Consciousness

Consciousness is distributed throughout the brain Characteristics of REM sleep • Prefrontal cortex is key for • Presence of rapid-eye-movements conscious control of information • Increased autonomic nervous system activity processing, inactive in sleep. • EEG resembles that of awake state (beta wave) Accounts for “irrationality of ” • Motor paralysis (except for diaphragm) • Reticular Formation controls • Presence of dreaming alertness. Damage to the reticular formation can lead to coma. • Neurons in Pons critical in generating REM sleep • Medial Medulla important in inhibiting motor movements. Damage leads to acting out our dreams. What we know about dreams

Length of dreams • Approximates the time it would take in waking life Content • Our eye movements are correlated with dream activity Who Dreams? • Everyone dreams, not everyone remembers, “Non-dreamers” less likely to remember 46% vs 83%. How much do we dream? • 4 or 5 bouts of about 10-20 dreams a night (20%) • Age differences in REM

Sleep Additional Findings About REM Does everyone sleep? Do we only dream during REM? • Nonsomniacs • Story type dream only found in REM. NREM more like passing • Individual differences in sleep needs thoughts or thinking. Recent research suggests dreams occur at other times. • How much sleep should you have. Most 8 hours but wide individual differences. • Lucid dreaming

Do we need REM sleep? NREM? • Deprivation studies show REM rebound – Since stages 3 & 4 of deep sleep also involved, people feel more tired and bothered by muscle and bone pain • Dreams may be way of exercising our neurons to keep them in shape or getting oxygen to cornea • REM sleep is correlated with learning. – REM sleep increases in college students during examination time. – Deprivation of REM sleep impairs the ability to learn complex tasks

Mortality Rates and Sleep

Sleep Deprivation. Do you go crazy without sleep? • The cases of Peter Tripp and Randy Gardner (264 hours or 11 days without sleep) • Key finding: Lack of sleep makes you tired but no physical damage. If sufficiently motivated you can perform quite well Are we sleep deprived? • Estimates are that 50% of population needs more sleep. • Studies show that optimal functioning helped by getting regular sleep of 8 hours or more and those who increased their sleep time did better. – Problems of in older people.

(Figure adapted from Kripke et al., 1979) Sleep Problems

Periodic limb movement disorder • Restless leg or kick that wakes up. Increases with age. • Problem of breathing and sleeping at the same time. SIDS • Sudden intrusion of Rem sleep causing (loss of skeletal muscle tone) hypnagogic hallucinations. Persistent daytime sleepiness. • Deficiency in Orexin or brain receptors for the neurotransmitter. Orexin keeps you awake rather than alternating between sleep and wakefulness. • Unlike normals, move directly to REM sleep at night. tape

Sleep Problems How to sleep like a baby Insomnia. • -you cannot get to sleep when you go to • Do you really need that much sleep as you think? • Sleep awakening-you get to sleep but you keep waking up • Early termination-you get to sleep but you wake up too early • Clear you mind of obsessive thoughts and worries • Light sleep-you feel that you never really got to sleep before going to bed. Paradoxical intention. • Keep a regular schedule of sleeping and waking and avoid long afternoon . • Don’t got to bed until you are tired. • Make your bed a place to sleep. • Adopt a regular program of exercise. • Should you exercise before going to bed. • Avoid sleep medications. • Have faith that your circadian rhythms will carry you though the next day

’ Psychodynamic View of Consciousness Sigmund Freud s Theory of Dreams

Freud believed dreams gives us a closer look at the workings of the unconscious. Divided dreams into: Freud argued that three mental systems form consciousness • Manifest content of a dream or the story of our dream • Latent content or the source of the dream in the unconscious • Conscious: mental events that you are aware of • Preconscious: Mental events that can be brought Freud thought dreaming allows us to remain sleeping into awareness when any of the following threaten to wake us: • Unconscious: Mental events that are inaccessible • nocturnal sensory impressions to awareness; events are actively kept out of • daytime preoccupations awareness • unconscious impulses. “Dream Work” Common Dream Symbols Body - houses • According to Freud, dream work allows us to incorporate those Parents - royalty, persons in power things which threaten to wake us by disguising images of the Siblings - little animals or vermin impulses which created them. Birth - water • The extent of the disguise depends on the individual’s “dream Dying - journey censor.” Uniform – nakedness • Since dreams contain visual symbols we are likely to miss their Rhythmic activities, dancing, playing piano—intercourse or symbolic meaning. masturbation • Distortions are dynamic, emotions may appear opposite to what Penis - generally any object that can penetrate, or is pointed or they are. elongated, or defy gravity. Sticks, knives, umbrellas etc., Female genitalia - churches, ovens, receptacles Breasts – apples, peaches, fruit in general Male genitalia - machinery, a grouping of three Where do these symbols come from? Is there empirical support for dream symbols?

Are Dreams the workings of Unconscious? Hypnotic Phenomena

Problems with Freud Disinhibition- will people engage in behavior that is • Freud’s dream theory has difficulty with “Sexual” Dreams and unusual or immoral “nonsexual” dreams. • People will follow suggestions. (Orne & Evans,1965) Snake, • Problem with Freud is that he suggests that there is a homunculus nitric acid, assault 5/6 followed directions. Complicating factor is that controls our behavior that nonhypnotized people will often follow directions too. Sensory distortions or hallucinations An alternative explanation: Hobson and McCarley’s • Some report auditory or visual hallucinations. Brain areas Activation-Synthesis Theory activated differently than if asked to imagine • Random firing from subcortical brain structures reach the cortex Posthypnotic suggestions creating “stimuli” that the cortex attempts to explain in a dream. Analgesia • Brain tries to make sense of these images in our dreams. Recovery of forgotten memories • This is the reverse of Freud who believed that meaning occurred first creating the dream, rather than random signals being given Age regression meaning.

Can You Fake Being Hypnotized? Theories of

Are people who are hypnotized engaged in a social role? Fooling hypnotist relatively easy. Adoption of social role of hypnotized person • Non hypnotized can often handle pain and show highly similar But how do you explain analgesia? emotional and physiological reactions. Hilgard's "Hidden Observer“ • Some differences A case of dissociation. – Hallucinatory experiences different Altered state of consciousness? – Will be likely to declare they are “extremely hypnotized” Most recent evidence suggests EEGs look different. The case of Kenneth Bianchi, the “Hillside Strangler” • Under hypnosis discovered alter ego in multiple personality of Steve Walker