Psychology Chapter on Sleep and Consciousness

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What role do circadian rhythms play in sleep?

They regulate the timing and quality of sleep. (correct)

They determine the exact number of sleep cycles a person needs.

They have no significant impact on sleep patterns.

They solely dictate the duration of REM sleep.

Which of the following accurately describes the human sleep cycle?

It includes five distinct stages with varying brain activity. (correct)

It lasts exactly 8 hours regardless of external factors.

It primarily involves deep sleep without any REM phases.

It consists of only two stages: REM and non-REM.

What is a common consequence of sleep deprivation?

Improved immune response.

Higher risk of chronic health conditions. (correct)

Enhanced cognitive functioning.

Increased energy and productivity.

Which statement best describes consciousness?

Consciousness is the subjective experience of the world. Signup and view all the answers

How is consciousness often described in relation to the nervous system?

As a vague concept that can be described but not measured. Signup and view all the answers

What is the primary physiological basis of narcolepsy?

Low levels of orexins Signup and view all the answers

Which of the following is a symptom of Seasonal Affective Disorder (SAD)?

Symptoms worsening in the morning Signup and view all the answers

What condition is characterized by paralysis upon waking or falling asleep?

Narcolepsy Signup and view all the answers

Why is light exposure therapy often effective for SAD?

It resets the body's circadian rhythm Signup and view all the answers

What is a possible evolutionary explanation for narcolepsy?

It provides a defense mechanism through tonic immobility Signup and view all the answers

What is a benefit of sleep related to neuronal connections?

Promotes robust and appropriate neuronal connections Signup and view all the answers

What primarily regulates circadian rhythms in organisms?

Light cues Signup and view all the answers

Which of the following factors influence sleep patterns across species?

Nervous system complexity Signup and view all the answers

How are human circadian rhythms typically characterized throughout the day?

Most alert mid-morning Signup and view all the answers

What are the three major factors that characterize sleep?

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

What role does melatonin play in sleep patterns?

It influences sleep timing through homeostatic mechanisms Signup and view all the answers

What occurs in the human body around 4:30 AM during sleep?

Deepest sleep phase occurs Signup and view all the answers

Which of the following is NOT mentioned as a cost of sleep?

Physical fatigue Signup and view all the answers

What primary symptoms characterize insomnia?

Sleep difficulties despite sufficient opportunities for sleep and decreased daytime function Signup and view all the answers

What is primarily indicated when discussing Stage V of sleep?

Rapid eye movements and high brain activity akin to wakefulness Signup and view all the answers

What are common influences on chronic insomnia?

Chronic stress and anxiety Signup and view all the answers

What is paradoxical sleep in the context of REM sleep?

Robust brain activity coupled with an immobilized body Signup and view all the answers

What is a potential evolutionary factor influencing sleep disorders today?

Mismatched environments from ancestors to now Signup and view all the answers

Which condition is associated with disruptions in circadian rhythm?

Seasonal affective disorder Signup and view all the answers

Which factor is NOT typically a contributor to the development of insomnia?

A dark, cool sleeping environment Signup and view all the answers

Which of the following best describes acute insomnia?

Short-term insomnia lasting for a few days or weeks Signup and view all the answers

What characterizes REM sleep?

Brain waves similar to the awake state with rapid eye movement. Signup and view all the answers

Which statement best describes NREM Stage II of sleep?

K-complexes are observed and external stimuli are often ignored. Signup and view all the answers

What role does delta wave activity signify during sleep?

It is associated with deep sleep and physiological renewal. Signup and view all the answers

What is the function of sleep spindles during NREM sleep?

They are involved in memory consolidation of 'facts'. Signup and view all the answers

During which stage of sleep does a person experience hypnagogic imagery?

NREM Stage I Signup and view all the answers

Which of the following statements about sleep patterns throughout a person's life is true?

They typically exhibit variability throughout the lifetime. Signup and view all the answers

What is primarily measured in an EEG during sleep?

Electrical activity and voltage patterns of the brain. Signup and view all the answers

What is the primary benefit of deep sleep (NREM Stage III/IV)?

Facilitates cellular maintenance and tissue repair. Signup and view all the answers

Which sleep disorder is specifically characterized by episodes of interrupted breathing during sleep?

Sleep apnea Signup and view all the answers

Which recommendation is considered helpful for better sleep?

Avoid caffeine and nicotine late in the day Signup and view all the answers

What is the latent content of a dream according to Freud’s Dream Protection Theory?

The underlying symbolic meaning of a dream Signup and view all the answers

What aspect of Freud's theory explains the drive to have instinctive urges satisfied?

Pleasure principle Signup and view all the answers

Which of the following is NOT a proposed function of dreaming according to evolutionary hypotheses?

Enhancing intuition about dreams Signup and view all the answers

What is the outcome of Freud’s Dream Protection Theory as evaluated by most scientists?

Rejected due to lack of evidence Signup and view all the answers

Which activity is suggested as a relaxing pre-sleep routine?

Taking a warm bath Signup and view all the answers

What does the reality principle entail according to Freud?

Adjusting behavior based on environmental constraints Signup and view all the answers

Study Notes

Introductory Psychology I - Fall 2024

Consciousness, Sleep, and Disorders covered in this unit.

Learning Objectives

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

What is Consciousness?

Consciousness is our subjective experience of the world, our bodies, and our mental perspectives.
Consciousness cannot be measured, therefore it doesn't exist as a singular entity.
Consciousness is self-awareness.
Consciousness is considered a unitary experience of an organism with a nervous system.
Consciousness is a vague concept not easily defined.

What is Sleep?

Sleep is a resting state across species.
Sleep deprivation is linked to a wide range of chronic health conditions (e.g., cardiovascular disease, diabetes, cancer, immune dysfunction).
Sleep is implicated in mental health disorders such as anxiety, depression, and Alzheimer's.

Why do We Sleep?

Costs of sleep include lost time and vulnerability.
Benefits of sleep include making robust neuronal connections (learning, memory, emotional processing, brain maturation) and overall maintenance of the body (protein synthesis, neurotransmitter regeneration, and cell division).

Sleep is Fundamental to Animal Life

Sleep is as fundamental to animal life as seeking food and reproduction.
Sleep seems to be a universal requirement for having an organized nervous system.

The Individual Decision to Sleep

Internal, external, and physiological factors determine the decision to sleep.
Factors include circadian time, body's metabolic state, hunger, inflammation, the immune system's function, elevated corticosterone levels, predation risk, mating opportunities, and seasonal and migratory status.

Circadian Rhythms

Behavioral and physiological changes, that adhere to a 24-hour cycle.
Regulated by changes in genetic expression through the day by proteins acting as biological clocks.
Changes in these proteins affect hormone levels, metabolic processes, and body temperature.
Biological characteristics shared across various organisms by these proteins.
Light is a primary cue for circadian regulation across diverse taxa.
Sleep timing is part of the organism's circadian rhythm. How much time a species allocates to sleep in a 24-hour period is influenced by evolution and feedback loops and homeostatic mechanisms (like melatonin).

Human Circadian Rhythms

Humans generally are most mentally alert mid-morning.
Physical activity is best mid-afternoon.
Sleepiness usually begins around 9 pm.
Deepest sleep usually occurs in the early morning hours near 4:30 am (lowest body temperatures).
Various time spans are included and shown in graph, such as the hours of fastest reaction time, highest body temperature, etc.

How to Describe Sleep?

Length of sleep, ratio of NREM to REM sleep, and timing of sleep are major factors characterizing sleep.
Across species, the allotment and timing of sleep are influenced by ecological and physical constraints.

Factors Influencing Sleep Patterns Across Species

Nervous system complexity, dietary patterns, body size, sociality, and life history.

Human Sleeping Patterns

Variability exists in how sleep is distributed across cultures and individuals.
Some cultures have continuous sleep at night and others experience biphasic sleep (with daytime naps).
Sleep patterns can even vary throughout an individual's lifetime.

The Human Sleep Cycle

Non-REM sleep involves physiological processes and brain wave slow-down (important for cellular, developmental, and tissue repair).
REM sleep involves brain waves similar to wakefulness, rapid eye movements, muscle immobilization, dreams, and memory and emotional process consolidation.
Alternations between cycles are key.

How We Measure Sleep: Brain Waves

Brain wave frequencies (EEG) reflect electrical activity and voltage patterns which vary with brain activity.
In an awake brain, activity produces high-frequency, chaotic (beta) waves, while deep sleep displays low-frequency (delta) waves. Dreaming brains exhibit activity very similar to awake brains.

NREM Stage I: Light Sleep

Switching from wakefulness to sleep.
Brain wave slow-down (theta waves) as physiological functions slow down.
Hallucinations and jerky movements possible.
Hypnagogic imagery can occur (scrambled, bizarre, and dreamlike images).

NREM Stage II: Light Sleep

Characterized by theta waves interspersed with sleep spindles and K-Complexes.
Sleep spindles are thought to be necessary for memory consolidation while K-Complexes are associated with memory consolidation and ignoring external stimuli.
K-complexes are observed only during sleep.
Body temperature drops slightly and eye movements stop.
This stage accounts for about 65% of sleep.

NREM Stage III/IV: Deep Sleep

Also known as slow-wave sleep, required for refreshing physiological processes and renewal.
Deep sleep shows further physiological slow-down, and subjects are difficult to wake.
Stage III is important for memory consolidation.
Stage IV is when tissue repair is thought to occur.
Suppressed by alcohol. Delta waves are prominent.

Stage 5: REM Sleep

Characterized by brain waves (alpha, beta) similar to those when awake, rapid eye movements, and muscle immobilization.
This state includes dreaming.
Robust brain activity and muscle immobilization is known as paradoxical sleep.

Discussion Break

Prompt to consider if you experience sleep deprivation and if efforts to improve sleep hygiene were effective.

Major Evolutionary Factors Behind Many Sleep Disorders

Modern environments differ significantly from the ones our ancestors lived in.
Many sleep disorders are likely impacted by mismatches (e.g., anxiety and hectic lifestyles; technology).
Modern technologies and lifestyles play a role.
Misunderstanding of sleep cycles.
Lack of awareness about circadian rhythms and light exposure.

Insomnia

Persistent difficulty with sleep initiation, or quality of sleep.
Two primary symptoms: sleep difficulties in spite of sufficient sleep opportunities and decreased daytime functioning due to poor sleep quality or duration.
Different forms of insomnia (acute or chronic).

Various Forms of Insomnia

Difficulty staying asleep, or falling back asleep after waking.
Most adults experience acute insomnia (lasting days or weeks) or chronic insomnia (three or more nights a week for a substantial period like 3 months).

Physiological Basis of Insomnia

Factors such as bright light close to bedtime, caffeine/alcohol intake, warmth, exercise habits, and inconsistent bedtimes.
Chronic stress and anxiety are important, especially in terms of difficulty falling asleep.

Seasonal Affective Disorder (SAD)

Symptoms of depression related to winter months.
More prevalent in individuals who live in higher latitudes.
Likely related to a shift in circadian rhythm with the change in day lengths.
Light exposure therapy is potentially effective.

Mismatches and Insomnia

Light, particularly blue light, disrupts melatonin secretion.

Narcolepsy

Rare neurological disorder (approximately 0.02% of the population).
Three key characteristics: overwhelming daytime sleepiness, paralysis during waking/sleep transitions, and cataplexy (muscle loss triggered by emotions).
Autoimmune disease is considered a possible physiological cause.

Physiological Basis of Narcolepsy

Assays show low levels of brain hormones (orexins) associated with wakefulness and arousal.
Loss of cells in the hypothalamus that produce orexins (likely due to autoimmune destruction of these cells).

Is Narcolepsy an "Evolutionary Hangover"?

"Tonic immobility," or feigning death.
Neurological similarities between this state and narcolepsy.

Other Sleep Disorders

Sleep apnea, night terrors, and sleepwalking.

Some Recommendations for Better Sleep

Go to bed and wake up at the same time daily.
Avoid caffeine, nicotine, and alcohol late in the day.
Don't eat heavy meals close to bedtime.
Exercise daily but not too close to sleep.
Relax before bedtime (read, knit, take a warm bath, pet a dog, meditate).
A slightly cool room temperature.
Avoid screens before bed.
Get sunlight as soon as you wake up.

Consciousness - Dreams and Other Altered States - Learning Objectives

Describe and compare three theories of dreaming (Dream protection theory, activation synthesis theory, and neurocognitive theory).
Understand how "unusual" alterations to consciousness occur (near-out-of-body, near-death, mystical).
Describe common myths related to hypnosis and explain two hypotheses that might explain it (sociocognitive theory and dissociation theory).

Why do We Dream?

Byproduct hypotheses (emotional memory processing, integration of new experiences, reorganizing and consolidating memories).
Evolutionary hypotheses (learning new strategies, simulating threats).

Most Frequent Dream Themes

List of recurring dream themes (being chased, lost, falling, flying, losing possessions, sexual dreams, great beauty, being naked, injury, or illness).

Freud's Theory of Unconsciousness

Unconsciousness includes mental activities unavailable for direct reflection, but influence conscious processes and behavior.
Freud proposed two theories: pleasure principle (urge satisfaction) – unconsciousness – and reality principle (behavior adjustment) – consciousness.

Freud's Dream Protection Theory

Dreams represent wish fulfillment and a symbolic attempt to realize unfulfilled desires.
Trauma and shameful desires are relegated to the unconscious.
Dreams have manifest content (remembered plot) and latent content (hidden symbolism).

Evaluation of Freud's Dream Protection Theory

Rejected by most scientists, mostly because it lacks evidence.
Few (less than 10%) sexual dreams.
Mostly straightforward, not symbolic, dream content.
Negative dream content.

Activation-Synthesis Theory

Dreams are the brain's attempt to make sense of random neural signals during REM sleep.
Pons (brain stem area) generates these signals that affect the forebrain.
Damage to the forebrain can eliminate dreaming.

Neurocognitive Theory

Dreams are meaningful products of cognitive capacity.
Shape what we dream about.
Children's dreams are simple and lack movement.
Adult dreams display complexity and are linked to neurodevelopment.
Supported by evidence that dreams are strongly related to life experiences.

Nightmares vs Night Terrors

Nightmares are sudden waking episodes with remembered bizarre and frightening dreams; association with PTSD.
Night terrors involve screaming, perspiring, confusion; usually in children.

Lucid Dreaming

Sleep and wakefulness may not be as distinct as once thought.
Lucid dreaming occurs when one knows that a dream is a dream.
About 20% of people report regular lucid dreams.
Some can control their dreams (especially nightmares).

Consciousness - Drugs - Learning Objectives

Describe brain's reward system and how drug use can lead to addiction.
Distinguish between different drug types and effects on consciousness.
Compare three evolutionary perspectives explaining our preference for consuming alcohol.

Why do Addictive Drugs Exist?

Chemicals naturally occurring deter herbivores.
Neurotoxins (usually produced in greater quantities in nature) enough to paralyze, or kill small animals, but have a minimal impact on large vertebrates, such as humans.
Plant defenses and coevolution occur over time.
Insect resistance to chemicals developed.
Many toxic chemicals become helpful.

Artificial Selection and Genetic Modification

Increase of THC in marijuana cultivation (evolved over time).

Processing and Synthetics

Processing of natural compounds (e.g., 300 pounds of coca leaves to produce one pound of cocaine) for drugs.
Synthetic/designer drugs (spice, fentanyl, synthetic nicotine, MDMA, synthetic amphetamines).

Why Do We Like Using Some Drugs?: The Reward System

The reward system is complex and interacts with the mesolimbic and mesocortical areas.
The most important signaling molecule is dopamine and it's located in the Nucleus Accumbens.

Evolution of the Reward System

Mediate natural rewards (positive feelings) that help animals learn and promote behavior for obtaining those rewards.
This system has functions in variety of contexts like parental care, foraging, and social behaviors.

What Initiates the Reward System?

Researchers characterized 'reward center' in the 1950s by stimulating the VTA with implanted electrodes in rats.
Rats would repeatedly press levers to engage the electrical stimulation (even when starving).
Method to understand natural activation of reward system.

Endogenous Opioids

Are neuropeptides that the pituitary gland releases.
Important in regulating the reward systems and in regulating emotions by reducing pain and stress.
Released during activities like eating, exercise, and sex.

Exogenous Opioids

Derived from opium poppy (opiates).
The most common derivative is morphine; other derivatives (heroin, oxycodone, hydrocodone, fentanyl, codeine).
Bind to μ-opioid receptors, which also bind endogenous opioids.

Reward System and Substance Addiction

All drugs affect the mesolimbic system, but differ in how.
In intoxication phase, the VTA/NAc pathway shows increased dopamine signaling.
Craving phase involves a reduced dopamine baseline.
Amygdala and PFC activation lead to craving.
Compulsive seeking phase is when the global recruitment of brain structures (PFC, hippocampus) leads to compulsive seeking and use of drugs.

Synaptic Transmission

Drug use can cause stable changes to the synapses of neurons in the reward system.

Impacts of Drugs

Repeated drug use has increasing consequences: cravings, dependencies, and many other unwanted effects.
Manifested as withdrawal.

Quick Break

Drug addiction was historically treated like a crime, but today a patient treatment approach is increasingly prevalent.
Different perspectives in understanding the reward system.
Is this new perspective more appropriate?

Different Addictive Drugs Disrupt the System in Different Ways

Stimulants (nicotine, cocaine, amphetamines) rev up the central nervous system.
Depressants (alcohol) lower central nervous system activity.
Narcotics (opioids) directly target the reward system.
Psychedelics (hallucinogens) alter perceptual experiences profoundly.

Summary of Drug Effects - I & II

Comprehensive tables of drug types(marijuana, alcohol, nicotine, caffeine), their effects, and withdrawal symptoms.

Substance Use Disorder - The DSM-5

Two or more criteria in a 12-month period.
Criteria that are used to diagnose substance use disorders are listed (e.g., hazardous use, social/interpersonal problems, neglected roles, legal problems, withdrawal, tolerance).

Impacts of Substance Use Disorder

Crude rate statistics related to opioid toxicity deaths (for particular regions and years).

Why do We Remain Vulnerable to Substance Use Disorders?

Adaptive and non-adaptive perspectives (e.g., reproductive/survival benefits, mismatch, life-history).
Whether our preference is adaptive or not, the capacity to make associations between stimuli and reactions is crucial at the root of addictions.

A Reproductive Benefit Perspective

Drug use enhances the perception of status, control, and attractiveness.
This may lead to greater success in male-male competition.

A Survival Perspective

Plants produced toxic chemicals.
Toxic chemicals (e.g., nicotine) have potential medicinal benefits for some larger animals.
Moderate amounts might have useful antiparasitic effects.

A Life History Perspective

People prone to taking risks are more likely to experience substance abuse.
Risk-taking tendencies can vary by sex (higher in males) and age (higher in young adults).

A Mismatch Perspective

Some psychoactive chemicals were originally harmless for our ancestors.
Chemical concentrations are much higher now with artificial processing.
Higher risk of addiction.

Alcohol Preference and Abuse

Universal preference for alcohol consumption.
Potentially, alcohol was part of our evolutionary past due to foraging and socializing.
Modern lifestyles increase the likelihood of abuse.

Alcohol facilitated social bonds in our ancestors.
Intoxication could lead to increased reproductive events.

Sanitation Hypothesis

Fermented beverages were potentially safer than contaminated water.

The "Drunken Monkey" Hypothesis

Preference for slightly fermented fruit (like alcoholic drinks) as an adaptation of our ancestors.
Related to foraging behavior of animals.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your understanding of the relationship between sleep, circadian rhythms, and consciousness with this quiz. Explore key concepts such as sleep cycles, sleep deprivation consequences, and disorders like narcolepsy and Seasonal Affective Disorder. This quiz is essential for grasping the physiological and psychological aspects of sleep.