AP Psychology: States of Consciousness - Comprehensive Guide

Historical Context and Overview of Consciousness

• Definition of Consciousness: The psychological definition of consciousness identifies it as the state of being aware of oneself and one's environment.
• Historical Evolution of the Study of Consciousness:
  • Early Psychology: William James, the author of the first psychology textbook, expressed significant interest in the study of consciousness.
  • Scientific Decline: Because early psychologists lacked the tools to examine consciousness scientifically, its study faded for a significant period.
  • Current Research: Consciousness has returned as a prominent research area due to two factors: the development of sophisticated brain-imaging tools and the increased emphasis on cognitive psychology.

Multi-Level Nature of Consciousness

• The Experience of Levels: Humans experience different levels of consciousness daily, often without conscious awareness. An example is performing a rhythmic action (like tapping a pen or moving a leg) while focus is occupied by reading. One level of consciousness controls the limb while another focuses on the text.
• The Mere Exposure Effect: This phenomenon occurs when individuals prefer stimuli they have encountered previously over novel stimuli, even if they have no conscious recollection of the previous encounter.
  • Named Example: A researcher shows participants a list of nonsense terms briefly. When later asked which terms they prefer from a new list, participants typically choose the terms they saw before, even though they cannot recall the original list.
• Priming: A closely related concept where research participants respond more quickly or accurately to questions or stimuli they have seen before, regardless of whether they remember the previous exposure.
• Blind Sight: A phenomenon where individuals who are medically or self-reportedly blind can accurately describe the path of moving objects or grasp items they claim they cannot see. This suggests one level of consciousness lacks visual information while another level is able to "see" and guide behavior.

Categorization of Conscious Levels

• Conscious Level: Information about yourself and your environment of which you are currently aware (e.g., focusing on the meaning of these specific words).
• Nonconscious Level: Body processes controlled by the mind that we are not usually (or ever) aware of. Examples include the control of heartbeat, respiration, and digestion.
• Preconscious Level: Information about yourself or your environment that is not currently in the conscious level but could be brought there upon request (e.g., remembering a favorite childhood toy).
• Subconscious Level: Information that we are not consciously aware of but that must exist due to observable behavior, such as the behaviors seen in priming or the mere exposure effect.
• Unconscious Level: A concept championed by psychodynamic psychologists who believe certain unacceptable events or feelings are repressed into this level. This concept is controversial among many psychologists because it is difficult or impossible to prove scientifically.

Mechanics of Psychoactive Drugs

• Definition: Psychoactive drugs are chemicals that alter brain (and body) chemistry to induce an altered state of consciousness.
• Psychological Factors: Changes in behavior or cognition are due to physiological processes but also to expectations. If an individual believes they have ingested a drug, they may exhibit expected effects (similar to the placebo effect).
• The Blood-Brain Barrier: The brain is typically protected from harmful chemicals in the bloodstream by thicker walls surrounding the brain's blood vessels. Psychoactive drug molecules are small enough to pass through this barrier.
• Agonists: Drugs that mimic naturally occurring neurotransmitters. They fit into the receptor sites on a neuron and function as the neurotransmitter normally would.
• Antagonists: Drugs that block neurotransmitters. While they do not fit the receptor site well enough to activate it, they fit well enough to occupy the space and prevent neurotransmitters or agonists from causing a reaction.
• Reuptake Inhibition: Some drugs prevent natural neurotransmitters from being reabsorbed back into the neuron, leaving an abundance in the synapse.
  • Specific Example: Prozac is a "selective serotonin reuptake inhibitor" (SSRI) that prevents the reabsorption of serotonin.
• Tolerance and Withdrawal:
  • Tolerance: A physiological change where the brain produces less of a specific neurotransmitter to compensate for the drug's presence, creating a need for more of the substance to achieve the same effect.
  • Withdrawal: Symptoms occurring when the drug is absent, ranging from caffeine-induced headaches to potentially fatal night sweats and dehydration seen in heroin addicts.
  • Dependence: Can be psychological (intense desire/conviction of need) or physical (existence of tolerance and withdrawal symptoms).

Classification of Psychoactive Drugs

• Stimulants:
  • Examples: Caffeine, cocaine, amphetamines, and nicotine.
  • Effects: Arouse the autonomic nervous system, speed up heart and respiration rates, and produce euphoria.
  • Side Effects: Disturbed sleep, reduced appetite, increased anxiety, and heart problems.
• Depressants:
  • Examples: Alcohol, barbiturates, and anxiolytics (tranquilizers/antianxiety drugs like Valium).
  • Effects: Slow down the autonomic nervous system, reactions, and judgment.
  • Alcohol Details: The most commonly used depressant. It affects the cerebellum, impacting motor coordination and the ability to stand. It is categorized as a depressant despite some feeling energized by it (which is due to lowered inhibitions and expectations).
• Hallucinogens (Psychedelics):
  • Examples: LSD, peyote, psilocybin mushrooms, and marijuana.
  • Effects: Cause sensory distortions, changes in reality perception, loss of identity, and vivid fantasies.
  • Reverse Tolerance: These drugs can persist in the body for weeks. A second dose added to the lingering amount can cause a greater effect than the first.
• Opiates:
  • Examples: Codeine, morphine, heroin, methadone, and fentanyl.
  • Effects: Act as agonists for endorphins, serving as powerful painkillers and mood elevators.
  • Notes: Derived from the poppy plant. Extremely physically addictive. Fentanyl is lethal even in minute quantities.

The Biology and Rhythms of Sleep

• Circadian Rhythm: A pattern of metabolic and thought processes that follow a $24$-hour cycle.
• Sleep Onset: The transition between wakefulness and sleep. The brain produces alpha ($\alpha$) waves. Mild hallucinations (like falling) may occur.
• NREM (Non-REM) Stages:
  • NREM Stage 1 and 2: Characterized by theta ($\theta$) waves. These are high-frequency, low-amplitude waves that slow down and increase in amplitude as sleep deepens.
  • NREM Stage 2 Specifics: Appearance of sleep spindles (short bursts of rapid brain waves).
  • NREM Stage 3 (Delta Sleep): Also called slow-wave sleep. Characterized by delta ($\delta$) waves (low-frequency). This is the deepest sleep stage where environmental awareness is lowest.
• Functions of Delta Sleep: Necessary for replenishing chemical supplies, releasing growth hormones in children, and fortifying the immune system. Physical exercise increases time spent in NREM sleep.
• REM (Rapid Eye Movement) Sleep:
  • Paradoxical Sleep: Brain waves appear as active and intense as they do when awake.
  • Characteristics: Eyes dart back and forth, and muscles may twitch.
  • Functions: Detailed dreams occur here. REM deprivation interferes with memory.
  • REM Rebound: If deprived of REM, an individual will experience longer REM periods the next time they sleep.
  • Cycle Patterns: Each cycle lasts approximately $90$ minutes. As morning approaches, we spend more time in Stage 1, 2, and REM, and less in Stage 3.
• Developmental Differences: Babies sleep up to $18$ hours a day and spend more time in REM sleep than adults. Total sleep and REM sleep need declines with age.

Sleep Disorders

• Insomnia: Affected by $10\,\%$ of the population. Persistent trouble falling or staying asleep. Treatments include behavior changes (reducing stimulants, consistent patterns). Sleeping pills are discouraged as they disturb sleep quality.
• Narcolepsy: Affects less than $0.001\,\%$ of the population. Sudden, unpredictable periods of intense sleepiness or falling directly into REM sleep. Can be treated with medication and strategic naps.
• Sleep Apnea: The person stops breathing for short periods during the night, gasps for air, and wakes up slightly. Rips the person of deep sleep. High risk for overweight men. Treated with a respiration machine.
• Night Terrors and Somnambulism (Sleepwalking):
  • Timing: Both occur during the first few hours of the night in stage 4 sleep (a deep NREM stage).
  • Target Population: Usually affects children. Most people outgrow them and do not remember the episodes.

Theories of Dreaming

• Definition: Storylike images experienced during sleep. "Lucid dreams" are those where the dreamer is aware and can control the storyline.
• Activation-Synthesis Theory: A biological theory proposing that dreams are the brain's interpretations of physiological activity during REM sleep. Dreams may have no more meaning than a physiological reflex.
• Information-Processing Theory: Suggests dreams help process daily events and integrate information into memory. Stress increases dream intensity. Babies may need more REM due to the volume of new information they process daily.
• Consolidation Theory: A subset of information-processing suggesting dreams help encode information from short-term memory into long-term memory.