Comprehensive Study Notes: Consciousness, Sleep, Psychoactive Drugs, Meditation & Hypnosis, Motivation, Sensation & Perception

Consciousness and Altered States

• Consciousness = awareness of internal events and of the external environment.

• Selective attention: controlling consciousness through deliberate concentration and full concentration.

• Alternate state of consciousness = any mental state different from ordinary waking consciousness (examples include sleep, dreaming, psychoactive drug use, hypnosis).

• What Is Consciousness? (overview of the above concepts).

Divided Attention and Everyday Distraction

• Example: texting and driving (driving while using a cell phone).

• Visual comparison: driver perception when not distracted vs. when talking on a cell phone; talking on a phone leads to missing critical cues.

• Time to collision (in seconds) data (from Strayer et al., 2011): baseline vs. cell phone condition shows increased risk of accident due to cognitive distraction.

• Reference: Strayer et al. (2011). Cognitive distraction while multitasking in the automobile, in B. Ross (Ed.), The Psychology of Learning and Motivation, 54, 29-58.

The Body Clock: Circadian Rhythms

• 24-hour biological clock affects alertness, body temperature, moods, blood pressure, pulse, etc.

• Daily peak in alertness in the middle of the day; lowest point at night.

• Suprachiasmatic nucleus (SCN) perceives darkness and signals the pineal gland to release melatonin.

• Final note: Circadian rhythms govern sleep–wake cycles and physiological readiness for activity.

Stages of Sleep

• There are five stages of sleep, each serving different purposes.

• A typical night cycles through the five stages several times (on average 4 to 6 times). The order is not always the same every cycle.

• Dreaming occurs in one of the five stages (REM sleep is the stage most associated with vivid dreaming).

Stage 1

• The lightest sleep stage; transition as you drift off.

• If you wake naturally, Stage 1 would be the last stage before full wakefulness.

• Duration: typically 5\text{ to }10\text{ minutes}; body slows and muscles relax.

Stage 2

• Still considered light sleep.

• Brain activity slows; heart rate and breathing slow.

• Body temperature falls slightly; body relaxes in preparation for deeper sleep.

Stage 3

• Start of deep sleep; called slow-wave sleep.

• Brain waves are slow \text{Delta waves}, with possible short bursts of faster activity (beta waves).

• If awakened during Stage 3, grogginess and confusion may occur.

Stage 4

• Deepest sleep; predominant delta-wave activity.

• Difficult to awaken someone in Stage 4.

• Associated with bedwetting or sleep terrors in children.

• Durations: typically 5 \text{ to } 15\text{ minutes} each, with the first deep sleep of the night often lasting about an hour.

• This stage is when the body does most of its repair and regeneration.

Stage 5: REM Sleep

• REM = rapid eye movement; also called active sleep.

• During REM: increased blood flow, breathing, and brain activity.

• Muscles in arms and legs experience periodic paralysis to prevent acting out dreams.

• First REM period begins about 90\text{ minutes} after sleep onset and lasts about 10\text{ minutes}.

• REM periods lengthen as the night progresses; final episode can last about an hour.

• Developmental note: Babies may spend up to half of sleep in REM; adults typically spend 20%-25% of sleep in REM, decreasing with age.

Why Do We Sleep? Four Theories

1. Adaptation/Protection theory: conserve energy and protect from predators.

2. Repair/Restoration theory: recuperate from daily activities.

3. Growth/Development theory: more sleep during periods of brain growth.

4. Learning/Memory theory: more REM sleep during periods of greatest learning.

Why Do We Dream? Three Theories

1. Wish-fulfillment: unacceptable desires repressed but emerge in dreams.

   • Manifest content = the story line of the dream.

   • Latent content = what the dream represents.

2. Activation-synthesis hypothesis: dreams are the brain’s attempt to make sense of random electrical stimulation during REM.

3. Cognitive view: dreams organize and interpret information from waking experience into memories.

Psychoactive Drugs

• Agonist drugs = enhance a particular neurotransmitter.

• Antagonist drugs = inhibit a neurotransmitter.

• Drug abuse = drug taking that causes emotional or physical harm to self or others.

• Addiction = body requires the drug to function; occurs through tolerance and dependence.

  • Psychological dependence

  • Physical dependence

  • Withdrawal

  • Tolerance

Four Major Drug Categories (Major Effects, Examples)

• Depressants (sedatives)

  • Examples: Alcohol, barbiturates, anxiolytics (e.g., Xanax, Rohypnol), Ketamine.

  • Desired effects: tension reduction, euphoria, disinhibition, drowsiness, muscle relaxation.

  • Undesirable effects: anxiety, nausea, disorientation, impaired reflexes, amnesia, slowed respiration, seizures, coma, death.

• Stimulants

  • Examples: Cocaine, amphetamine, methamphetamine (crystal meth), MDMA (Ecstasy); caffeine; nicotine.

  • Desired effects: exhilaration, euphoria, increased energy, reduced appetite, sociability.

  • Undesirable effects: irritability, anxiety, sleeplessness, paranoia, psychosis, elevated BP and temp, convulsions, death.

• Opiates (Narcotics)

  • Examples: Morphine, heroin, codeine, OxyContin.

  • Desired effects: euphoria, rush of pleasure, pain relief, withdrawal relief, sleep.

  • Undesirable effects: nausea, vomiting, constipation, painful withdrawal, shallow respiration, convulsions, coma, death.

• Hallucinogens (Psychedelics) and Cannabis

  • Examples: LSD, mescaline, psilocybin, marijuana.

  • Desired effects: heightened aesthetic appreciation, euphoria, mild delusions, perceptual alterations.

  • Undesirable effects: panic, nausea, more extreme delusions, hallucinations, perceptual distortions (bad trips), possible psychosis; marijuana can cause relaxation, mild euphoria, nausea relief, and perceptual changes; (note: effects vary widely by substance and dose).

Meditation and Hypnosis

• Meditation: results range from mellow relaxation to strong hallucinations.

• Meditation can lead to altered states of consciousness via purposeful changes in prefrontal cortex function.

• Mechanism: by focusing on a single object, emotion, or word, fewer brain cells are allocated to multitasking; experience a sense of timelessness and mild euphoria due to changes in neural resource allocation.

• Hypnosis: a trance-like state of heightened suggestibility, deep relaxation, and focused attention.

• Medical use: used to reduce pain levels and shorten pain duration in anxiety-provoking situations (e.g., dentistry, childbirth).

Motivation and Emotion

• Motivation: a set of factors that activate, direct, and maintain behavior toward a goal.

• Emotion: subjective feeling that includes arousal, cognitions, and expressed behaviors.

• Theories of Motivation (Biological, Psychological, Biopsychosocial):

  • Biological: Instincts, Drive reduction, Optimal arousal.

  • Psychological: Incentive, Cognitive.

  • Biopsychosocial: Maslow’s hierarchy of needs.

• Major Theories of Motivation

  • Instincts: fixed, unlearned response patterns; early theories (McDougall, 1908) proposed many instincts; genetics role in competitions and behavior.

  • Drive-reduction theory: motivation begins with a physiological need that elicits a drive to satisfy the need; once satisfied, homeostasis is restored and motivation decreases.

  • Optimal-arousal theory: organisms are motivated to achieve and maintain an optimal level of arousal.

  • Incentive theory: motivation results from external stimuli that pull an organism in certain directions (external rewards or punishments).

  • Cognitive theories: motivation is affected by attributions (how we explain actions) and expectancies (what we think will happen).

  • Maslow’s hierarchy of needs (Biopsychosocial): basic needs (physiological, safety) must be met before higher needs (belonging, self-actualization).

  • Extrinsic motivation: motivation based on external rewards or punishment.

  • Intrinsic motivation: motivation driven by internal satisfaction from the task itself.

Chapter Nine: Attending, Perceiving, and Understanding Sensation and Perception

Sensation vs. Perception (Definitions)

• Sensation = the process of detecting, converting, and transmitting raw sensory information from the external and internal environments to the brain.

• Perception = the process of selecting, organizing, and interpreting sensory information into meaningful patterns.

Sensation vs. Perception (Illustration)

• Sensation: raw data processed by sensory receptors (eyes, ears, nose, skin, tongue).

• Perception: brain processes sensations into meaningful interpretations (example: brain interprets light waves as a tree).

Processing Sensation (Sense and Stimulus-to-Neural Pathways)

• Sense: Vision (light waves), Audition (sound waves), Olfaction (m smells), Gustation (taste), Body senses (pressure, touch, pain, temperature).

• Stimulus: various external stimuli that elicit sensory responses.

• Receptors: light-sensitive rods and cones in the retina (vision); pressure-sensitive hair cells in the cochlea (hearing); neurons in olfactory epithelium (smell); taste buds on the tongue (taste);

• Transduction: conversion of stimuli into neural impulses (action potentials).

• Coding: brain differentiates physical stimuli via neural pathways and patterns.

• Processing: from receptors to brain, leading to perception.

Sensory Adaptation

• Sensory adaptation: when a constant stimulus is present, receptors become less sensitive and fire less frequently.

• Example: presence of many cats in a neighbor’s house but the owner may not notice smells; smell and touch adapt readily, vision and intense stimuli may not as readily.

Perception: The Organization of Sensory Information

• Perception = selection, organization, interpretation of sensory information to form a useful mental representation of the world.

• Illusions vs. hallucinations vs. delusions:

  • Illusion: false or misleading impression due to perceptual errors or distorted stimuli.

  • Illusions are not the same as hallucinations (false sensory experiences without external stimuli) or delusions (false beliefs).

Perception’s Three Basic Processes

1) Selection
2) Organization
3) Interpretation

Selective Attention and Attention-Related Phenomena

• Selective attention: choosing important information and filtering out the rest (cannot attend to everything).

• Feature detectors: neurons specialized to respond to specific stimuli (e.g., faces); example condition: prosopagnosia (inability to identify a person by facial features).

• Habituation: decrease in responding to repeated stimulation; we are more responsive to changes in our environment (e.g., compliments from strangers feel more exciting than from a long-term partner).

Organization: Gestalt Form Perception

• Figure-ground: distinguishing objects from the background.

• Reversible figures: images that can be interpreted in more than one way.

• Gestalt principles (organization of perceptual inputs): similarity, proximity, closure, continuity, common region, and more.

Depth Perception and Depth Cues

• Depth perception: ability to perceive 3D space using binocular and monocular cues.

• Visual cliff: crawling infants often refuse to move to the “deep end,” indicating depth perception.

Perceptual Constancies

• Perceptual constancies: the tendency to perceive objects as stable despite changes in size, shape, color, or brightness.

Perceptual Set and Context

• Perceptual set: readiness to perceive stimuli in a particular way based on expectations; we see what we expect to see.

• Frame of reference: perception is influenced by context; interpretation of stimuli depends on surrounding cues.

Processing Approaches in Perception

• Bottom-up processing: analysis begins with raw sensory data sent to the brain for higher-level processing.

• Top-down processing: higher-level processing starts with expectations and knowledge, guiding interpretation of sensory input.

• Reading example: you learned to read with bottom-up processing; the ability to read with top-down processing allows recognition of nonsensical text due to context and prior knowledge (illustrative typos in the sample sentence).