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Explore different states of consciousness, sleep patterns, and brain activities during sleep stages. Learn about the necessity of sleep, including REM sleep, brain wave patterns, and sleep disorders like insomnia and sleepwalking.
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Consciousness • Consciousness • a person’s awareness of everything that is going on around him or her at any given moment • Waking consciousness • state in which thoughts, feelings, and sensations are clear and organized, and the person feels alert
Consciousness • Altered state of consciousness • state in which there is a shift in the quality or pattern of mental activity as compared to waking consciousness • Medical Definition of altered state of consciousness. : any of various states of awareness (as dreaming sleep, a drug-induced hallucinogenic state, or a trance) that deviate from and are usually clearly demarcated from ordinary waking consciousness.
Sleep • Sleep is a naturally recurring state of mind characterized by altered consciousness, relatively inhibited sensory activity, inhibition of nearly all voluntary muscles, and reduced interactions with surroundings. It is distinguished from wakefulness by a decreased ability to react to stimuli. Mammalian sleep occurs in repeating periods, in which the body alternates between two highly distinct modes known as non-REM and REM sleep. REM stands for "rapid eye movement" but involves many other aspects including virtual paralysis of the body.
Necessity of Sleep • Circadian rhythm: a cycle of bodily rhythm that occurs over a twenty-four-hour period • “circa”: about “diem”: day • Hypothalamus: tiny section of the brain that influences the glandular system • suprachiasmatic nucleus • deep within the hypothalamus • the internal clock that tells people when to wake up and when to fall asleep
Necessity of Sleep • Hypothalamus tells the pineal gland to secrete melatonin which makes a person feel sleepy. • Microsleeps: brief sidesteps into sleep lasting only a few seconds • Sleep deprivation: any significant loss of sleep results in irritability and problems with concentration
Necessity of Sleep • Adaptive theory: theory of sleep proposing that animals and humans evolved sleep patterns to avoid predators by sleeping when predators are most active
Necessity of Sleep • Restorative theory: theory of sleep proposing that sleep is necessary to the physical health of the body and serves to replenish chemicals and repair cellular damage
Stages of Sleep • Rapid eye movement (REM): stage of sleep in which the eyes move rapidly under the eyelids and the person is typically experiencing a dream • NREM (non-REM) sleep: any of the stages of sleep that do not include REM
Brain Wave Patterns • Electroencephalograph (EEG) • allows scientists to see the brain wave activity as a person passes through the various stages of sleep and to determine what type of sleep the person has entered • alpha waves: brain waves that indicate a state of relaxation or light sleep • theta waves: brain waves indicating the early stages of sleep • delta waves: long, slow waves that indicate the deepest stage of sleep
Brain Activity During Sleep
Stages of SleepAmerican Academy of Sleep Medicine (AASM) rules • N1 (R&K Stage 1): light sleep • may experience: • hypnagogic images: hallucinations or vivid visual events • hypnic jerk: knees, legs, or whole body jerks • N2 (R&K Stage 2): sleep spindles • sleep spindles: brief bursts of activity only lasting a second or two Rechtschaffen and Kales (R&K) criteria is an older standard.
Stages of SleepAmerican Academy of Sleep Medicine (AASM) rules • N3(R&K Stages 3 and 4): delta waves pronounced • deepest stage of sleep: 50 percent or more of waves are delta waves • body at lowest level of functioning • time at which growth occurs Rechtschaffen and Kales (R&K) criteria is an older 4 stage standard.
REM Sleep and Dreaming • REM sleep isparadoxicalsleep (high level of brain activity) • If wakened during REM sleep, sleepers almost always report a dream. • REM rebound: increased amounts of REM sleep after being deprived of REM sleep on earlier nights
Sleep Disorders • Nightmares • bad dreams occurring during REM sleep • REM behavior disorder: In a person with REM sleep behavior disorder (RBD), the paralysis that normally occurs during REM sleep is incomplete or absent, allowing the person to "act out" his or her dreams. RBD is characterized by the acting out of dreams that are vivid, intense, and violent.
Stage Four Sleep Disorders • Sleepwalking (somnambulism) • episode of moving around or walking around in one’s sleep • occurs in deep sleep • more common among children than adults
Stage Four Sleep Disorders • Night terrors • the person experiences extreme fear and screams or runs around during deep sleep • doesn’t wake fully • relatively rare disorder
Problems during Sleep • Insomnia: the inability to get to sleep, stay asleep, or get a good quality of sleep • Sleep apnea: disorder in which the person stops breathing for nearly half a minute or more • continuous positive airway pressure device (CPAP) is the leading therapy for sleep apnea. Patients wear a face or nasal mask during sleep. The mask, connected to a pump, provides a positive flow of air into the nasal passages in order to keep the airway open.
Problems during Sleep • Narcolepsy: sleep disorder in which a person falls immediately into REM sleep during the day without warning With cataplexy: sudden loss of muscle tonetriggered by strong emotions such as laughter. (Things you didn’t know #8)
Dreams Why People Dream and What They Dream about • Freud: dreams as wish fulfillment • manifest content: the dream itself • latent content: the true, hidden meaning of a dream
Dreams • Activation-synthesis hypothesis: dreams are created by the higher centers of the cortex to explain the brain stem’s activation of cortical cells during REM sleep periods
The Brain and Activation-Synthesis Theory According to the activation-synthesis theory of dreaming, the pons in the brainstem sends random signals to the upper part of the brain during REM sleep. These random signals pass through the thalamus, which sends the signals to the proper sensory areas of the cortex. Once in the cortex, the association areas of the cortex respond to the random activation of these cortical cells by synthesizing (making up) a story, or dream, using bits and pieces of life experiences and memories
Dreams • Activation-information-mode model (AIM) • revised version of the activation-synthesis explanation of dreams • information that is accessed duringwaking hours can have an influence on the synthesis of dreams
Dreams AIM Activation-information-mode model
Hypnosis • Hypnosis: state of consciousness in which the person is especially susceptible to suggestion
Hypnosis • Four elements of hypnosis: • hypnotist tells the person to focus on what is being said • person is told to relax and feel tired • hypnotist tells the person to “let go” and accept suggestions easily • person is told to use vivid imagination • Hypnotic susceptibility: degree to which a person is a good hypnotic subject
Hypnotic susceptibility measures how easily a person can be hypnotized. Several types of scales are used; however, the most common are the Harvard Group Scale of Hypnotic Susceptibility and the Stanford Hypnotic Susceptibility Scales.
Theories of Hypnosis Hypnosis is a process through which subjects become susceptible to suggestion. The two main theories that explain the hypnotic trance are referred to as state (Hilgard) and non-state theories. They respectively argue that hypnosis is either a dissociative state or a relaxed state that accepts suggestion. Both psychologists held that hypnosis could be effective.
State Theory of Hypnosis • Hypnosis as dissociation: According to dissociation theory, hypnosis represents a special altered state of awareness in which their consciousness is split into two components: a hypnotized component (the hypnotized self) and a non-hypnotized part (the hidden observer). The hidden observer maintains an accurate perception of the world, exerting its influence to maintain limits on the behaviors produced by the hypnotized self.
Non-State Theory of Hypnosis • Social-cognitive theory of hypnosis: people who are hypnotized are notin an altered state, but are merely playing the role expected of them in the situation • The premise of socio-cognitive theory is that being a hypnotized subject is a social role. People voluntarily immerse themselves in this role, and like all social roles, the way people behave and even how they perceive events is influenced by their expectations and knowledge regarding the rules of this particular social role.
Psychoactive Drugs • Psychoactive drugs: drugs that alter thinking, perception, and memory • Physical dependence • tolerance: more and more of the drug is needed to achieve the same effect • withdrawal: physical symptoms resulting from a lack of an addictive drug in the body systems • can include nausea, pain, tremors, crankiness, and high blood pressure
Psychoactive Drugs • Psychological dependence: the feeling that a drug is needed to continue a feeling of emotional or psychological well-being is a form of dependence that involves emotional–motivational withdrawal symptoms (e.g., a state of unease or dissatisfaction, a reduced capacity to experience pleasure, or anxiety) upon cessation of drug use or engagement in certain behaviors.
Stimulants • Stimulants: drugs that increase the functioning of the nervous system • amphetamines: drugs that are synthesized (made in labs) rather than found in nature • cocaine: natural drug; produces euphoria, energy, power, and pleasure • nicotine: active ingredient in tobacco • caffeine: the stimulant found in coffee, tea, most sodas, chocolate, and even many over-the-counter drugs
Nicotine • The harmful effects of nicotine are now well known, but many people continue to smoke or chew tobacco in spite of warnings
Depressants • Depressants: drugs that decrease the functioning of the nervous system • barbiturates: depressant drugs that have a sedative effect • benzodiazepines: drugs that lower anxiety and reduce stress • Rohypnol: the “date rape” drug
Alcohol • Alcohol:the chemical resulting from fermentation or distillation of various kinds of vegetable matter • often mistaken for a stimulant, alcohol is actually a CNS depressant
Narcotics • Narcotics • opium-related drugs • suppress the sensation of pain by binding to and stimulating the nervous system’s natural receptor sites for endorphins. • opium: substance made from the opium poppy and from which all narcotic drugs are derived • morphine: narcotic drug derived from opium; used to treat severe pain • heroin: narcotic drug derived from opium that is extremely addictive
Hallucinogens • Psychogenic Drugs • drugs including hallucinogens and marijuana that produce hallucinations or increased feelings of relaxation and intoxication • hallucinogens: drugs that cause false sensory messages, altering the perception of reality • LSD (lysergic acid diethylamide): powerful synthetic hallucinogen • PCP: synthesized drug now used as an animal tranquilizer that can cause stimulant, depressant, narcotic, or hallucinogenic effects
Hallucinogens • Psychogenic Drugs • MDMA (Ecstasy or X): designer drug that can have both stimulant and hallucinatory effects • Stimulatory hallucinogenics: drugs that produce a mixture of psychomotor stimulant and hallucinogenic effects
Marijuana • marijuana (pot or weed): mild hallucinogen derived from the leaves and flowers of a particular type of hemp plant
Hallucinations • Hypnogogic hallucination: hallucination that can occur just as a person is entering N1 (light) sleep • Hypnopompic hallucination: hallucination that happens just as a person is in the between-state of being in REM sleep (in which the voluntary muscles are paralyzed) and not yet fully awake
