Sleep and Circadian Rhythms Quiz

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Questions and Answers

What physiological change is associated with narcolepsy?

Increased secretion of melatonin

High levels of orexins

Loss of hypothalamic cells producing orexins (correct)

Elevated cortisol levels

Which group is more likely to experience Seasonal Affective Disorder (SAD)?

People living at southern latitudes

Individuals descending from northern latitudes (correct)

People who have never lived in colder climates

Individuals from tropical regions

What is a common symptom of narcolepsy?

Hallucinations while waking (correct)

Inability to sleep for prolonged periods

Chronic insomnia

Excessive sleep during the night

How does light exposure affect circadian rhythms?

It disrupts melatonin secretion Signup and view all the answers

What triggers cataplexy in individuals with narcolepsy?

Emotional responses Signup and view all the answers

What are the benefits of sleep?

Facilitating rapid metabolic processes Signup and view all the answers

Which factor primarily regulates circadian rhythms?

Light Signup and view all the answers

How does sleep timing in humans typically vary during a 24-hour period?

Deepest sleep in early morning hours Signup and view all the answers

What major factors characterize sleep according to the content provided?

Length of sleep, ratio of NREM to REM sleep, and timing of sleep Signup and view all the answers

What influences the amount of sleep a species gets in a 24-hour period?

Ecological and physiological constraints Signup and view all the answers

What typically happens to human alertness during the mid-morning?

Mental alertness peaks Signup and view all the answers

Which of the following factors is NOT mentioned as influencing sleep patterns across species?

Environmental pollution levels Signup and view all the answers

What physiological process is increased during sleep?

Neurotransmitters are regenerated Signup and view all the answers

What is the primary role of Non-REM sleep?

Cellular maintenance and tissue repair Signup and view all the answers

Which brain wave patterns are associated with deep sleep?

Delta waves Signup and view all the answers

What happens during REM sleep?

Muscle immobilization occurs Signup and view all the answers

Which of the following statements is true about sleep spindles?

They play a role in memory consolidation Signup and view all the answers

In which stage of sleep are K-Complexes primarily observed?

Stage II Signup and view all the answers

What characterizes REM sleep?

Induced paralysis of voluntary muscles Signup and view all the answers

What occurs in NREM Stage I sleep?

There may be jerky movements and hallucinations Signup and view all the answers

How is the sleep cycle characterized?

Alternations between NREM and REM sleep Signup and view all the answers

Which of the following is a symptom of insomnia?

Waking up frequently throughout the night Signup and view all the answers

What physiological changes occur during NREM Stage III/IV sleep?

Physiological processes slow down further Signup and view all the answers

Which factor is NOT likely to influence chronic insomnia?

Consistent exercise Signup and view all the answers

What is often considered a physiological basis of insomnia?

Anxiety disorders Signup and view all the answers

Stage IV sleep is associated with what process, similar to Stage III?

Tissue repair Signup and view all the answers

How is seasonal affective disorder classified?

Circadian rhythm disorder Signup and view all the answers

Which component is a major factor affecting sleep disorders?

Technological advancements Signup and view all the answers

What defines chronic insomnia according to clinicians?

Experiencing three nights of poor sleep weekly for three months Signup and view all the answers

What does Freud's Dream Protection Theory primarily suggest about dreams?

Dreams represent wish fulfillment and symbolize unfulfilled desires. Signup and view all the answers

Which of the following is NOT a recommendation for better sleep?

Engage in heavy meals close to bedtime. Signup and view all the answers

Which of the following statements accurately reflects one of the learning objectives regarding altered states of consciousness?

Explaining how mystical experiences occur. Signup and view all the answers

What is the 'latent content' of a dream according to Freud?

The hidden meanings and symbols within a dream. Signup and view all the answers

Which of the following disorders is characterized by involuntary episodes of stopping breathing during sleep?

Sleep apnea Signup and view all the answers

Which hypothesis suggests that dreaming helps in the processing of emotional memories?

Byproduct hypotheses Signup and view all the answers

Why has Freud’s Dream Protection Theory been largely dismissed by scientists?

It relies heavily on subjective interpretations. Signup and view all the answers

What is a potential benefit of getting sunlight as soon as you wake up?

It helps regulate circadian rhythms and improve mood. Signup and view all the answers

What role do circadian rhythms play in sleep?

They help regulate the timing of sleep and wakefulness. Signup and view all the answers

Which statement accurately describes the human sleep cycle?

It includes five stages, where REM sleep occurs multiple times. Signup and view all the answers

What is the general definition of sleep across species?

A rest state characterized by reduced activity. Signup and view all the answers

How is sleep deprivation linked to health conditions?

It can aggravate chronic health conditions and mental disorders. Signup and view all the answers

What is one characterization of consciousness?

It is a subjective experience that includes self-awareness. Signup and view all the answers

Study Notes

Introductory Psychology I - Fall 2024

Course covers consciousness, sleep, and disorders.

Learning Objectives

Define circadian rhythm and its role in sleep regulation.
Describe the human sleep cycle, including the 5 stages.
Detail various sleep disorders.

What is Consciousness?

Consciousness is subjective experience of the world, body, and mental perspectives.
Sleep, drugs, and other experiences can alter consciousness.
Consciousness is self-awareness and a unitary experience of an organism with a nervous system.

What is Sleep?

Sleep, across species, is a resting state.
Sleep deprivation is linked with several health conditions, including cardiovascular disease, diabetes, cancer, and immune dysfunction.
Sleep is implicated in mental health disorders like anxiety, depression, and Alzheimer's.

Why do we Sleep?

Costs of sleep include lost time and vulnerability.
Benefits include making robust neuronal connections, maintaining body function (e.g., protein synthesis, neurotransmitter regeneration, cell division), and supporting development (e.g., learning, memory, emotional processing, brain maturation).
Sleep is fundamental to animal life, as important as seeking food and reproduction. It's a universal requirement of an organized nervous system.

The Individual Decision to Sleep

Individual decisions to sleep are determined by internal, external, and physiological factors.
Factors include circadian time, metabolic state, hunger, satiety, immune function, inflammation, elevated corticosterone, predation risk, mating/migratory status, and species-specific factors.

Circadian Rhythms

Circadian rhythms are behavioral and physiological changes in an organism that adhere to a 24-hour cycle.
These rhythms are regulated by changes in genetic expression through the day via "biological clocks" (proteins).
Changes in these proteins affect hormone levels, metabolic processes, and body temperature, sharing genetic and functional characteristics across diverse organisms.
Light is the primary cue for circadian regulation.
The timing of sleep is part of an organisms' circadian rhythm.

Human Circadian Rhythms

Humans tend to be most mentally alert mid-morning, but physically active mid-afternoon.
Sleepiness typically begins around 9 pm, and deepest sleep occurs early morning hours when body temperatures are lowest (around 4:30 am).
Sleep is distributed variably across cultures and individuals: some sleep continuously at night, others in a biphasic pattern (night and daytime nap).

How to Describe Sleep?

Three key factors characterize sleep: length, ratio of NREM to REM sleep, and timing of sleep.
Allotment and timing of sleep reflect species ecological and physiological constraints.

Factors Influencing Sleep Patterns Across Species

Factors include nervous system complexity, dietary patterns, body size, sociality, and life history.

Human Sleeping Patterns

Sleep patterns vary among cultures and individuals.
Some experience continuous night sleep; others have a biphasic sleep pattern (night and daytime nap).
Sleep patterns also vary across an individual's lifetime.

The Human Sleep Cycle

Non-REM sleep involves physiological and brain wave slowing, crucial for cellular maintenance, development, and tissue repair.
REM sleep, characterized by rapid eye movement and brain waves similar to wakefulness, is crucial for memory consolidation and emotional processing.
Alternating cycles of NREM and REM sleep occur throughout the night.

How We Measure Sleep: Brain Waves

EEG recordings of electrical activity (voltage patterns) reveal brain wave frequencies that vary with activity.
Awake brain activity shows high-frequency, chaotic beta waves.
Deep sleep shows low-frequency delta waves.
Dreaming brain activity resembles awake activity.

NREM Stage I: Light Sleep

The first stage of sleep, transitioning from wakefulness, is characterized by slower theta waves and general physiological slowing.
Hypnagogic imagery, like dream-like images, may occur.

NREM Stage II: Light Sleep

Characterized by theta waves, sleep spindles, and K-complexes. Sleep spindles and K-complexes are thought to be crucial for memory consolidation and external stimuli filtering.
This is also a period of slowing body temperature, heart rate, and muscle relaxation, along with ceasing eye movements. This is about 65% of sleep.

NREM Stage III/IV: Deep Sleep

Slow-wave sleep, also called deep sleep, is essential for refreshment and physiological renewal.
Brain activity slows further, and subjects are hard to wake.
This stage is important for memory consolidation, and possibly for tissue repair.
Sleep at this stage is suppressed by alcohol.

Stage 5: REM Sleep

REM sleep displays brain waves similar to wakefulness and rapid eye movements.
Breathing and heart rate increase.
Voluntary muscle activity ceases during this stage.
Vivid dreaming occurs during REM sleep, which is considered paradoxical sleep.

Discussion Break

Reflect on sleep habits and efforts to improve sleep hygiene.

Major Evolutionary Factors Behind Sleep Disorders

Evolutionary mismatch: Modern environments differ significantly from those our ancestors evolved in.
Many sleep disorders are likely impacted by this mismatch, including anxiety disorders, and those related to technology (hectic lifestyles), artificial light, and misunderstanding of sleep cycles.

Insomnia

Characterized by persistent difficulty with sleep initiation, duration, consolidation, or quality.
Symptoms include sleep difficulties when opportunities exist, and reduced daytime function.
Acute insomnia is common, lasting days or weeks, while chronic insomnia occurs over 3 months.

Various Forms of Insomnia

Some individuals experience difficulty staying asleep or falling asleep initially.
Others wake up after falling asleep, spending a few hours awake before falling back asleep.
Most adults experience acute insomnia, but a chronic form involves three or more nights of poor sleep per week for 3 months.

Physiological Basis of Insomnia

Insomnia is influenced by bright light close to bedtime, caffeine/alcohol, a warm room, and exercise too close to bedtime.
Inconsistent bedtimes can also cause chronic insomnia, which is commonly related to stress and anxiety.

Seasonal Affective Disorder (SAD)

SAD is a circadian rhythm disorder, marked by depression during winter and resolution with summer arrival.
More prevalent at higher latitudes, it likely reflects a circadian rhythm shift due to varying day lengths.
Light exposure therapy is often an effective treatment.

Mismatches and Insomnia

Light, especially blue light, interferes with melatonin secretion.
Melatonin is a crucial hormone for regulating circadian rhythm.

Narcolepsy

Narcolepsy is a uncommon disorder (about 0.02% of the population).
Characterized by overwhelming daytime sleepiness (sleep attacks), muscle paralysis upon waking or falling asleep (cataplexy), and hallucinations.

Physiological Basis of Narcolepsy

Low levels of brain hormones (orexins), associated with wakefulness and arousal, are associated with narcolepsy.
A loss of hypothalamic cells that produce orexins is considered a possible cause, likely due to autoimmunity.

Is Narcolepsy an "Evolutionary Hangover"?

"Tonic immobility," or feigning death used by some animals as a defense strategy, also resembles narcoleptic cataplexy.
Neurological parallels are observed.

Other Sleep Disorders

Sleep disorders include sleep apnea, night terrors, and sleepwalking.

Some Recommendations for Better Sleep

Maintain consistent bed and wake times.
Avoid caffeine, nicotine, and alcohol late in the day.
Avoid large meals close to bedtime.
Incorporate daily exercise but avoid it close to bedtime.
Relax before bed with activities like reading, knitting, a warm bath, or pet interaction.
Maintain a slightly cool room temperature.
Minimize screen time before bed and exposure to light in general.
Get natural sunlight upon waking.

Consciousness – Dreams and Other Altered States

Learning objectives include comparing dream theories (Dream protection theory, activation synthesis theory, neurocognitive theory).
Discussion includes alterations in consciousness (near-death, mystical).
Description of common myths related to hypnosis, and two hypotheses that might explain it.

Why Do We Dream?

Byproduct hypotheses include processing emotional memories, integrating new experiences with existing ones, and reorganizing and consolidating memories.
Evolutionary hypotheses include learning new strategies and simulating threatening events.

Most Frequent Dream Themes

Most frequent themes include being chased or pursued, being lost or trapped, falling or flying, losing possessions, sexual dreams, experiencing beauty, being naked/dressed oddly and injury or illness.

Freud's Theory of Unconsciousness

Freud's theory describes unconsciousness as mental activity that influences conscious processes but is unavailable for direct reflection.
The pleasure principle drives satisfaction of instinctive urges and desires. The reality principle recognizes environmental constraints, allowing adjustment and control of behavior.

Freud's Dream Protection Theory

Freud's theory posits that dreams represent wish fulfillment and an attempt to realize unfulfilled desires.
Freud's theory suggests that trauma and shameful desires are stored in the unconscious mind and manifest as dreams.
Freud described two types of dream content: manifest content (the remembered plot) and latent content (the hidden symbolic meaning).

Evaluation of Freud's Dream Protection Theory

Most scientists reject Freud's theory due to a lack of empirical evidence.
Sexual dreams are less common than imagined by Freud's theory.
Dream content is often straightforward rather than symbolic.
Negative themes are common in dreams.
Post-trauma nightmares are a distinct possibility.

Activation-Synthesis Theory

Dreams are the brain's attempts to create meaning from random neural signals generated during REM sleep.
Signals originate in the pons and travel to the forebrain, particularly the parietal lobes.
Damage to these areas can prevent dreaming, even if the pons are intact.

Neurocognitive Theory

Dreams are a product of cognitive capacities that shape what dreams are about.
Cognitive achievements influence dream content, especially between children and adult dreams.
Dreams relate to neurodevelopment and life experience.

Nightmares vs. Night Terrors

Nightmares involve detailed, bizarre dreams that cause fear, leading to waking.
Night terrors involve screaming, increased sweating, confusion leading back to deep sleep, and aren't commonly remembered.
Nightmares are more often associated with PTSD or PTSD treatment.

Lucid Dreaming

Lucid dreaming involves the awareness that a dream is a dream.
A person in a lucid dream may sometimes have control over their surroundings.
About 20% of individuals report regular lucid dreams.
Lucid dreaming may help with nightmares, but not other issues.

Alterations in Consciousness

Hallucinations are realistic perceptual experiences in the absence of external stimuli.
Hallucinations activate the brain in ways similar to processing real sensory input.
Hallucinations are relatively common, affecting 10-35% of people.
They can arise from various sources, including sensory deprivation, hypoxia, and drugs.

Out-of-Body Experience (OBE)

An OBE involves a sense that consciousness has left the body.
OBEs are more common among people with other unusual experiences.
OBEs can occur during some disorders and with drugs.
Studies show there is no real detachment from the body.

Near-Death Experiences (NDEs)

NDEs differ across cultures based on different expectations around the afterlife, but some consistent themes exist.
NDE-like experiences are reported following exposure to drugs, hypoxia, and temporal lobe stimulation.

Common Features of NDEs

Difficulty describing the experience in words.
Experiencing pronounced death, feelings of peace/quiet, hearing unusual noises, meetings with spiritual beings, experiencing bright light, panoramic life review, experiencing realms of knowledge/experiences/limits, and sensing return to the body.

Are NDEs the Result of DMT?

Some similarities are observed between NDEs and exogenous DMT experiences, but we know the body produces small amounts of DMT spontaneously.
Further research needed to determine why this occurs.

Mystical Experiences

Mystical experiences involve a sense of unity or oneness with the world.
These experiences are often religious in nature and can be triggered by various experiences (fasting, seizures, prayer, and drugs).
Drug-induced mystical experiences can be beneficial but must be treated cautiously.

Hypnosis

Hypnosis is an interpersonal situation where suggestions influence conscious thought and change perceptions and behavior in the subject.
It can be a useful adjunctive therapy, but has lower effectiveness alone.
About 15-20% of people are highly susceptible to hypnosis, with similar numbers showing less suggestibility.

Hypnosis Myths

Hypnosis is not a trance state or a magical event.
It does not negate people's control over their thoughts or actions.
There is no significant biological difference between hypnosis and wakefulness.
Hypnosis is not a sleeplike state, and doesn't fundamentally change how the brain functions.

Theories of Hypnosis

Sociocognitive theory views hypnosis as an example of personal beliefs and attitudes impacting experience.
Dissociation theory explains hypnosis as a temporary separation of personality functions.

Consciousness - Drugs

Learning objectives include describing the brain's reward system and its connection to drug use and addiction, distinguishing drug types and effects, and comparing evolutionary perspectives on preferences for alcohol.

Why Do Addictive Drugs Exist?

Naturally occurring psychoactive chemicals, like alkaloids (e.g., caffeine, nicotine), cannabinoids (e.g., THC, CBD), and opioids, evolved in plants to deter herbivores, acting as neurotoxins.

A Coevolutionary Arms Race

Over time, plants increase the concentration of these chemicals, while insects develop resistance to them.

From Toxic to Helpful

Some insect species have evolved immunity to these plant chemicals.
Monarch butterflies store the toxic alkaloids produced by milkweed and use them to deter predators.

Artificial Selection and Genetic Modification

THC content in cannabis has increased significantly through artificial selection and genetic modification.

Processing and Synthetics

Some natural compounds, like cocaine and various opiates, require extensive processing to be used as drugs.
"Designer Drugs" and synthetic versions are often created based on natural compounds.

Why Do We Like Using Drugs - The Reward System

The brain´s reward system involves the interacting mesolimbic and mesocortical systems.
Dopamine is a key signaling molecule in this system located in the Nucleus Accumbens.

Evolution of the Reward System

The reward system, mediating "natural rewards" (like food and sex), helps animals learn and repeat behaviors leading to these rewards.
This system has broader roles in a variety of contexts, including parental care, foraging, and social behaviours.

What Initiates the Reward System?

In the 1950s, researchers characterized the brain's "reward center" using implanted electrodes to stimulate the VTA (ventral tegmental area) and activating the mesolimbic system.
This approach demonstrated that reward system activation can be achieved without the use of electrodes.

Endogenous Opioids

Endogenous opioids like endorphins, released by the pituitary gland, regulate emotion, reward, and reduce pain and stress during activities such as eating, exercising, and sex.

Exogenous Opioids

Opioids, derived from opium poppies, are widely used to treat pain and are included in numerous drug forms like morphine, heroin, oxycodone, hydrocodone, fentanyl, and codeine
Opioids, similar to endorphins, bind to mu-opioid receptors, mimicking their effects.

Reward System and Substance Addiction

Addictive drugs affect the mesocorticolimbic system but often do so in different ways.
The process of substance addiction frequently follows a pattern: intoxication, craving and compulsive seeking and use of the drug.

Impacts of Drugs

Repeated drug use frequently leads to the growing prevalence of cravings, dependencies, and various unwanted side effects.
Withdrawal refers to the phenomenon observed when the baseline amount of neurotransmitters descends too low due to repeated drug use and is reflected on other systems' disruptions.

Quick Brake

Historically, individuals with drug addiction were treated as criminals, but now more as patients.
Understanding the reward system clarifies the reasons for and underlying mechanisms of this transition in approach.

Different Addictive Drugs Disrupt the System

Different addictive drugs, including stimulants, depressants, and narcotics, affect the reward system in varying ways, often increasing dopamine signalling.

Psychedelics

Psychedelics, also known as hallucinogens, profoundly alter perception, mood, and thoughts but do not directly involve the reward system.

Summary of Drug Effects

Summaries of the mechanisms and impacts of various drugs on psychology.

Substance Use Disorder - The DSM-5

The DSM-5 criteria for diagnosing substance use disorders are presented.

Impacts of Substance Use Disorder

This information presents data on opioid toxicity deaths by region over two periods (2016 and 2021).

Why Do We Remain Vulnerable to Substance Use Disorders?

Reproductive and survival benefits (e.g., potential reinforcement of behaviors that ensure survival and increased reproductive success).
Mismatch between modern environments and evolutionary past, with modern concentrations of psychoactive chemicals vastly exceeding past levels to which we might have developed a tolerance for or experience them as less toxic to our systems.

A Reproductive Benefit Perspective

Drug use can enhance a user's perception of status and desirability, potentially increasing mating success and reproductive opportunities.

A Survival Perspective

Plants evolved toxic chemicals to deter herbivores, with potential benefits for larger animals consuming them in moderate quantities, e.g., antiparasitic effects of nicotine.

A Life History Perspective

Risk-taking, which varies by sex and age, may increase vulnerability to substance abuse, particularly in young men.

A Mismatch Perspective

Modern environments often magnify psychoactive substances, posing greater risks for addiction even though our ancestors' natural exposure to such compounds likely had lower risks of addiction, given the lower concentrations involved.

Alcohol Preference and Abuse

A clear universal preference for alcohol consumption is likely related to evolutionary factors related to past environments, but modern environments increase the potential for abuse.

The social behaviours of our ancestors were positively reinforced by the effects of alcohol consumption, facilitating social bonds and potentially increasing reproductive success.

Sanitation Hypothesis

Alcohol may have been safer to drink than contaminated water in some historical contexts.

The "Drunken Monkey" Hypothesis

This hypothesis suggests that our predisposition for alcohol consumption evolved from a preference for ripe, fermenting fruit that our predecessors encountered in their environments.

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Description

Test your knowledge on the physiological aspects of sleep and circadian rhythms. This quiz covers topics such as narcolepsy, sleep disorders, and the effects of light on sleep patterns. Discover how various factors influence sleep and learn about the benefits it provides.