Chapter 4 – Consciousness & Its Alterations (Discovering Psychology 10e)

Consciousness

• Key definition: Personal awareness of mental activities, internal sensations, and the external environment.
• Key theme: Understanding waking awareness, how attention shapes it, and the dangers when attention is split.
• Historical roots
  • Rene Descartes
  • Dualism: separation of mind and body.
  • Body likened to an automaton; mind an intangible controlling entity.
• Early scientific method
  • Introspection → “looking in on oneself.”
  • Issues: subjective, scientifically immeasurable (e.g., “Is my red the same as your red?”).

Freud & the Unconscious

• Unconscious: Processing/behavior occurring without awareness.
• Freud’s iceberg analogy
  • Conscious above water.
  • Below: deep instincts & desires versus controlling forces.
• Modern update
  • Freud’s specifics (mother-fixation, psychic “forces”) lack evidence.
  • Valuable legacy: behavior & thought often occur outside awareness.
  • Cognitive unconscious: unexperienced mental processes giving rise to thoughts, choices, emotions, behavior.

Levels & States of Consciousness

• Minimal consciousness: low-level sensory responsiveness.
• Full consciousness: fully aware; able to report mental state.
• Self-consciousness: attention focused on the self as object.
• Altered states: drug-induced, brain trauma, etc.

Properties of Consciousness

• Unity
  • Experiences integrated into a whole (a painting ≈ swatches → unified scene).
• Selectivity
  • Attention = spotlight filtering for goal-relevant info; cocktail-party effect.
• Intentionality
  • Consciousness is about something; meaning shaped by intention (summiting a peak vs. admiring nature).
• Transience
  • Constant shift from one "now" to the next.

Perceptual Constancy (tie-in)

• Size constancy: object perceived same size despite retinal size change.
• Shape constancy: object recognized despite shape variance.

Attention: The Mind’s Spotlight

• Definition: Capacity to selectively focus awareness on external stimuli or internal thoughts.
• Characteristics
  • Limited capacity — prioritizes goal-relevant info.
  • Selective → inattentional blindness, change blindness, misdirection.
  • Division → multitasking ↓ accuracy and ↑ interference.
  • Visual tasks → inattentional deafness; auditory → inattentional blindness.
  • Using a cell phone while driving ≈ more dangerous than driving while legally drunk.
• Filtering mechanism
  • Unattended info often ignored; people unaware of what they miss (e.g., laptops in class, texting while driving).

Automatic vs. Controlled Processing

• Automatic
  • No conscious guidance; conscious intervention can hinder (e.g., walking).
• Controlled
  • Requires focus (e.g., learning a new skill).
• Same task can flip
  • Driving empty highway (automatic) vs. heavy traffic (controlled).

Unconscious Influence & Blindsight

• Blindsight: people with cortical blindness can react to unseen stimuli.
• Unconscious priming: prior exposure biases perception & behavior without awareness.

Cycles of Consciousness: Circadian Rhythms & Sleep

• Circadian rhythm: ≈ 24-hour cycle in physiological & psychological processes.
• Master clock: suprachiasmatic nucleus (SCN) in hypothalamus.
• Environmental synchronizers
  • Sunlight ↓ melatonin suppression.
  • Blue-light devices mimic daylight → ↓ melatonin → insomnia.
• Intrinsic rhythm: ≈ 24.2 h; drifts without cues (jet lag, blindness).

Sleep Research Basics

• EEG: tracks brain’s electrical activity.
• Brain remains active; patterns differ by stage.

Types & Stages of Sleep

• NREM (Stages 1–3)
  • Stage 1: mixture alpha & theta waves; hypnagogic hallucinations, myoclonic jerk.
  • Stage 2: sleep spindles, K-complexes, theta + beginnings of delta.
  • Stage 3: >50\% delta waves; deep slow-wave sleep.
• REM
  • Rapid eye movements, vivid dreams, muscle atonia, physiological arousal.
  • First REM episode ≈ 5–15 min; lengthens each 90-min cycle.

Sleep Across the Night & Lifespan

• Each cycle ≈ 90 min; REM length ↑, NREM ↓ through night.
• Total sleep ↑ childhood/adolescence; stable adulthood; ↓ late adulthood.

Why We Sleep

• Evolutionary adaptation: conserve energy, avoid hazards.
• Functions
  • Memory consolidation & integration.
  • Emotional regulation.
  • Clear metabolic waste, maintain immunity.

Sleep Deprivation

• Microsleeps: seconds-long intrusions.
• Impairments: ↓ concentration, vigilance, reaction time; ↑ calories/weight; mood swings.
• REM/NREM rebound after deprivation.
• Emotional brain overreacts (risk-taking, strong negative responses).

Dreams & Mental Activity

• Dream: unfolding perceptions, thoughts, emotions during REM (≈ 90\% recall if awakened).
• Sleep thinking: NREM stage 3; bland, ruminative.
• Content trends
  • Everyday settings; negative emotions (fear > happiness > confusion).
  • Gender: women report more emotions; men more physical aggression.
• Nightmares: vivid anxiety dreams in REM; only disorder if frequent/distressing.

Theories of Dreaming

• Freud
  • Manifest vs. latent content; repressed sexual/aggressive wishes (unsupported).
• Activation–Synthesis
  • Brainstem activation → cortex synthesizes story.
• Neurocognitive model
  • Continuity with waking cognition; dreams reflect personality, worries, interests.

Sleep Disorders

• Definition: Consistent disturbance causing distress or impaired daytime function.
• Insomnia
  • Trouble falling/staying asleep; daytime fatigue; causes include hyper-arousal, stimulants, anxiety.
• Obstructive Sleep Apnea (OSA)
  • Repeated breathing stoppage → daytime grogginess; treatment: lifestyle, CPAP.
• Narcolepsy
  • Excessive daytime sleepiness, sleep attacks, cataplexy (muscle loss with emotion).
• Parasomnias
  • Undesired arousal/actions: sleep terrors, sleepwalking, eating disorder, sexsomnia, exploding head syndrome.

Hypnosis

• Definition: Cooperative social interaction producing changes in perception, memory, thought, behavior via suggestion.
• Susceptibility: 15\% highly, 10\% resistant.
• Effects
  • Sensory changes, post-hypnotic suggestions.
• Limits
  • Cannot override will; best as adjunct to structured therapy.
• Explanations
  • State theory: dissociated consciousness streams.
  • Social-cognitive: role enactment, social expectations.

Meditation

• Definition: Sustained concentration techniques to focus attention & heighten awareness.
• Goals: Train attention.
• Types
  • Focused-attention (mantra).
  • Open-monitoring (present-moment).
• Empirical benefits
  • ↑ concentration, discrimination, attention, working memory, emotional control; ↓ stress.

Psychoactive Drugs

• Definition: Chemical substances altering arousal, mood, thinking, sensation, perception.
• Common effects
  • Physical dependence, tolerance, withdrawal, rebound, abuse, reward-circuit changes (dopamine).

Categories

• Depressants: ↓ CNS activity.
• Opioids: pain relief, euphoria (mimic endorphins).
• Stimulants: ↑ CNS activity, alertness.
• Psychedelics: distort perception & thought.

Depressants

• Alcohol
  • Low doses: euphoria, friendliness; high abuse potential.
  • Involved in >50\% assaults/homicides/accidents; \approx140{,}000 US deaths/yr.
  • BAC behavioral effects:
  • 0.05\% lowered alertness → 0.40\% ~ 50\% mortality.
• Barbiturates & Tranquilizers
  • Anxiety reduction, sleep; respiratory depression; severe withdrawal.

Opioids

• Natural: opium, morphine, codeine.
• Synthetic/Semi-synthetic: heroin, methadone, oxycodone, fentanyl.
• Withdrawal unpleasant but rarely fatal (cravings, GI distress).

Stimulants

• Caffeine
  • Blocks adenosine; stimulates dopamine; excess → anxiety, sleep disruption.
• Nicotine
  • ↑ activity frontal lobes, thalamus, hippocampus, amygdala; withdrawal: irritability, brain fog.
  • Vaping delivers nicotine/THC/CBD; lung injury cases.
• Amphetamines (Benzedrine, meth)
  • ↑ alertness, euphoria; rebound crash; long-term psychosis, brain damage.
• Cocaine
  • Blocks dopamine, serotonin, norepinephrine reuptake; intense euphoria; variable effects by route.
• Methamphetamine
  • Cheap, long-lasting high; frontal-lobe damage, emotional instability, violence.

Psychedelics

• Mescaline (peyote), Psilocybin (mushrooms), LSD (synthetic)
  • LSD mimics serotonin; risks: flashbacks, depression, psychosis; controlled trials suggest therapeutic potential.
• Marijuana (THC)
  • At high doses: sensory distortion, motor impairment; medical uses: pain, epilepsy, nausea, glaucoma.

Designer & Dissociative Drugs

• MDMA (Ecstasy)
  • Stimulant + mild psychedelic; ↑ serotonin release & block reuptake; risks: dehydration, hyperthermia, serotonin-nerve damage; studied for PTSD therapy.
• PCP & Ketamine
  • Dissociative anesthetics; affect glutamate; produce detachment, aggression; high doses → convulsions, death.

Psych for Your Life: Overcoming Insomnia

• Monitor stimulant intake.
• Establish calming bedtime routine.
• Optimize sleep environment.
• Consistent sleep–wake schedule.
• Stimulus-control therapy: associate bed with rapid sleep onset only.