chapter 4

Chapter 4: Consciousness

Definition of Consciousness

  • Consciousness is the subjective state of being aware of oneself, one’s thoughts, and/or the environment.

    • Features of consciousness include:

    • Alertness

    • Self-awareness

    • Having free will

    • A person's mental content, thoughts, and imaginings

      • Internal consciousness: includes feelings of pain, hunger, sleepiness, and awareness of thoughts and emotions.

      • External consciousness: refers to experiences outside of ourselves.

Forms of Consciousness

Sleep and Biological Rhythms

  • Biological Rhythm: The internal cycle of biological activity.

  • Circadian Rhythm: A 24-hour biological clock governing various bodily functions.

  • Sleep: A periodic, natural loss of consciousness involving distinct stages.

Daily Rhythms and Sleep

Types of Sleep Patterns

  • Larks and Owls: Daily rhythms vary among individuals based on age and genetic predisposition.

    • General alertness peaks:

    • Evening peak for 20-year-olds (“owls”).

    • Morning peak for 50-year-olds (“larks”).

Factors Affecting Circadian Rhythm

  • The circadian rhythm is resilient, often referred to as our biological clock, controlling bodily rhythms occurring on a 24-hour cycle.

  • Various physiological elements change over the 24-hour period, including:

    • Body temperature

    • Arousal/Energy levels

    • Mental sharpness

  • **Impact of Factors on Sleep: **

    • Biology/Genetics: Variation in sleep requirements (e.g., newborns average 16 hours, adults 8 hours or less).

    • Cultural Differences: Distinct patterns of sleeping across cultures; North Americans generally sleep less now than in the past due to artificial lighting influences.

Light and Sleep

  • Light plays a significant role in regulating sleep cycles by suppressing the hormone melatonin, which contributes to relaxation.

Stages and Cycles of Sleep

Distinct Sleep Stages

  • Sleep stages are characterized by distinct patterns of brain waves and muscle activity, with four identified stages.

  • Sleep Cycles: The process of transitioning through sleep stages occurs approximately every 90 minutes throughout the night.

REM Sleep

  • Discovered by Eugene Aserinsky in 1953, REM (Rapid Eye Movement) sleep is associated with dreams.

    • Characteristics of REM sleep:

    • Increased heart rate and rapid breathing.

    • Sleep paralysis occurs, where the brainstem blocks signals to the motor cortex, preventing movement.

    • Genital arousal occurs irrespective of dream content and persists post-REM.

NREM Sleep Stages

  • Stage 1: A transitional phase between wakefulness and sleep, characterized by alpha and theta brain waves.

  • Stage 2: The body reaches deep relaxation and exhibits sleep spindles in brain activity.

  • Stage 3: Deep sleep marked by the presence of delta waves.

Sleep Waves

  • Alpha Wave: Low frequency, high amplitude wave present during the awake state.

  • Theta Wave: Low frequency, high amplitude wave present in stages 1 & 2 of sleep.

  • Delta Wave: Low frequency, high amplitude wave prominent in stage 3 of sleep.

Effects of Sleep Loss on the Body

  • Sleep deprivation leads to impairments across various body systems, including cognitive, emotional, and physical aspects.

Dreams

Nature of Dreams

  • Dreams consist of sequences of images, emotions, and thoughts experienced during sleep.

    • Common themes in dreams include negative events or emotions, often termed failure dreams (being pursued, attacked, rejected).

    • Dreams rarely include sexual content and may incorporate real-world sounds and recent experiences.

Altering Consciousness: Drugs

Psychoactive Drugs

  • Definition: A chemical substance that alters brain function, leading to changes in perception, mood, or consciousness.

Dependence/Addiction

  • Many psychoactive drugs can harm the body and lead to dependence or addiction.

    • Dependence is defined as:

      • Physical Dependence: Body alterations create cravings for the substance, notably to alleviate withdrawal symptoms.

      • Psychological Dependence: Coping resources diminish as the drug becomes necessary to relax, socialize, or sleep.

    • Tolerance: Reduction in the drug’s effects with habitual use.

    • Withdrawal Symptoms: Discomfort and distress following cessation of use, including behavioral and physical challenges.

Depressants

  • Function: These drugs reduce neural activity and bodily functions.

  • **Examples: **

    • Alcohol

    • Barbiturates: depress CNS activity; reduce anxiety but impair memory and judgment.

      • Examples of barbiturates: Nembutal, Seconal, Amytal.

      • Effects: Inducing sleep, reducing anxiety, but also causing memory issues, judgment impairment, and potential overdose when mixed with alcohol.

    • Opioids: Derivatives of opium; highly addictive and depress CNS activity, notably reducing pain.

      • Examples include morphine and heroin.

      • High doses produce euphoria and act on endorphin receptors in the brain.

Stimulants

  • Function: Stimulants excite neural activity and accelerate bodily functions.

    • Physical Effects of Stimulants: Including dilated pupils, elevated heart and respiratory rates, increased blood sugar levels, and reduced appetite.

    • Examples of Stimulants:

    • Caffeine

    • Nicotine

    • Amphetamines and Methamphetamine

    • Cocaine

    • Ecstasy (MDMA)

Specifics of Stimulants
Caffeine

  • Increases energy and can disrupt sleep for 3-4 hours, leading to withdrawal symptoms such as headaches, irritability, fatigue, difficulty concentrating, and depression.

Nicotine

  • Primarily noted for its highly addictive properties.

Cocaine

  • Mechanism includes blocking reuptake of neurochemicals such as:

    • Dopamine (generating rewarding feelings)

    • Serotonin (elevating mood)

    • Norepinephrine (providing energy)

    • Associated Effects on Consciousness: Euphoria that lasts about 45 minutes, followed by agitation, depression, and increased pain sensations post-use.

    • Develops tolerance over time, worsening withdrawal symptoms; overdose can lead to severe health risks such as convulsions and heart attacks.

Methamphetamine

  • A highly addictive stimulant that accelerates CNS activities, leading to increased energy and significant mood swings.

    • Consequences: Include irritability, insomnia, seizures, hypertension, and potential for violent behavior and depression.

Ecstasy (MDMA)

  • Categorized as a synthetic stimulant and mild hallucinogen.

    • Effects on consciousness: Euphoria, CNS stimulation, hallucinations, and artificial feelings of intimacy.

    • Short-term effects can include regrettable behaviors, dehydration, overheating, and hypertension.

    • Long-term consequences may affect serotonin-producing neurons, leading to chronic mood disorders, disrupted sleep patterns, impaired memory, and weakened immune responses.

Hallucinogens

  • Types:

    • LSD (lysergic acid diethylamide), a powerful hallucinogenic drug.

    • THC (delta-9-tetrahydrocannabinol): The primary active psychoactive component found in marijuana.

Influences Leading to Drug Use

  • Various societal, personal, and environmental factors play significant roles in influencing drug use behaviors and decisions.