Psychology Chapter 5: Consciousness, Sleep, and Psychoactive Drugs

Sleep

Stages of Sleep

Sleep is divided into several stages, each characterized by distinct physiological and psychological features.

• Stage 1: Light sleep, transition between wakefulness and sleep.

• Stage 2: Deeper sleep, marked by sleep spindles and K-complexes in EEG.

• Stage 3 & 4: Deep (slow-wave) sleep, important for physical restoration.

• REM Sleep: Rapid Eye Movement sleep, associated with vivid dreaming and increased brain activity.

REM sleep occurs more at the end of the sleep period, while slow-wave sleep is more prevalent at the beginning.

Characteristics of REM Sleep

REM sleep is distinguished by unique physiological and psychological features.

• Rapid eye movements

• EEG similar to waking state

• Muscle atonia (paralysis of voluntary muscles)

• Increased heart rate and respiration

• Most vivid dreams occur during REM

Why Do We Sleep?

Sleep serves multiple functions, including restoration and adaptation.

• Restorative theories: Sleep restores depleted resources, regulates hormones, and supports immune function.

• Adaptive theories: Sleep evolved to protect organisms during periods of vulnerability.

Circadian Rhythms

Circadian rhythms are biological cycles regulated by environmental cues, such as light and temperature.

• Approximately 24-hour cycle

• Regulates sleep-wake patterns, hormone release, and body temperature

Comparative Analysis of Sleep

Functions of Sleep

• Physiological restoration

• Memory consolidation

• Emotional regulation

• Adaptive inactivity

Sleep Loss

Sleep deprivation can have significant effects on physical and mental health.

• Impaired cognitive performance

• Emotional instability

• Physical health problems

Effects of Sleep Loss

• Decreased attention and memory

• Impaired immune function

• Increased risk of accidents

• Chronic sleep deprivation can lead to serious health issues

Dreams

What Does REM Do?

REM sleep is important for brain development, memory consolidation, and emotional processing.

• REM deprivation studies show increased pressure for REM sleep

• Dreams are most vivid during REM

Lucid Dreams

Lucid dreaming occurs when the dreamer is aware they are dreaming and may exert control over the dream.

• Can be used to explore consciousness and problem-solving

Sleep Disorders

Types of Sleep Disorders

• Insomnia: Difficulty falling or staying asleep

• Narcolepsy: Sudden, uncontrollable sleep attacks

• Sleep apnea: Breathing interruptions during sleep

• Parasomnias: Abnormal behaviors during sleep (e.g., sleepwalking)

Psychoactive Drugs

Definition

Psychoactive drugs are substances that alter perception, mood, consciousness, and behavior by acting on the central nervous system.

Drug Administration and Absorption

• Oral: Easy and relatively safe, but slow absorption

• Injection: Rapid effects, but risk of infection and overdose

• Inhalation: Fast absorption, but can damage lungs

Drug Penetration of the CNS

• Drugs must cross the blood-brain barrier to affect the CNS

• Some drugs are metabolized before reaching the brain

Drug Tolerance and Sensitization

• Tolerance: Decreased response to a drug after repeated use

• Sensitization: Increased response to a drug after repeated use

Drug Withdrawal

Withdrawal symptoms occur when drug use is abruptly stopped, leading to physiological and psychological effects.

• Severity depends on drug type and duration of use

• Common symptoms: anxiety, irritability, nausea, sweating

Learning: Classical Conditioning and Drugs

Classical Conditioning in Drug Use

Drug-related cues can become conditioned stimuli, triggering cravings and withdrawal symptoms.

• Example: Environmental cues associated with drug use can elicit physiological responses

Alcohol

Short-Term Effects

• Impaired judgment and coordination

• Slurred speech

• Reduced inhibition

Withdrawal Effects

• Headache, nausea, sweating, anxiety

• Severe withdrawal can be life-threatening

Chronic Effects

• Liver damage

• Brain damage

• Increased risk of cancer

Heroin and Other Opiates

Short-Term Effects

• Euphoria

• Pain relief

• Drowsiness

Chronic Effects

• High risk of addiction

• Withdrawal symptoms: muscle aches, nausea, sweating

Addiction

Models of Addiction

• Disease model: Addiction is a chronic disease with biological and psychological components

• Learning model: Addiction is learned through reinforcement and social influences

• Cognitive-behavioral model: Thoughts and beliefs influence addictive behaviors

General Categories of Psychoactive Drugs

Category	Examples	Main Effects
Stimulants	Caffeine, Cocaine, Nicotine	Increase alertness and energy
Depressants	Alcohol, Benzodiazepines	Reduce neural activity, induce relaxation
Opiates	Heroin, Morphine	Pain relief, euphoria
Hallucinogens	LSD, Psilocybin	Alter perception and cognition
Cannabis	Marijuana	Altered perception, relaxation

Cocaine

Short-Term Effects

• Increased alertness and energy

• Euphoria

• Decreased appetite

Withdrawal Effects

• Fatigue

• Depression

• Craving

Marijuana

Short-Term Effects

• Altered perception of time and space

• Impaired memory and coordination

• Increased appetite

Chronic Effects

• Respiratory problems

• Possible cognitive impairment

Caffeine

Effects

• Increased alertness

• Improved mood

• Insomnia (at high doses)

• Increased heart rate

Health implications: Safe up to 400mg/day

Key Equations and Concepts

• Classical Conditioning Equation:

$US \rightarrow UR$

$CS + US \rightarrow UR$

$CS \rightarrow CR$

• Circadian Rhythm Equation:

$\text{Periodicity} \approx 24 \text{ hours}$

Summary Table: Drug Categories and Effects

Drug Type	Short-Term Effects	Long-Term Effects
Alcohol	Impaired judgment, relaxation	Liver damage, addiction
Heroin	Euphoria, pain relief	Addiction, withdrawal symptoms
Cocaine	Alertness, euphoria	Depression, fatigue
Marijuana	Altered perception	Respiratory issues
Caffeine	Alertness	Insomnia, fatigue

Additional info:

• Some explanations and examples have been expanded for clarity and completeness.

• Tables have been reconstructed to summarize drug categories and effects.