Mysteries of Consciousness

Consciousness

• Consciousness: a person's subjective experience of the world and the mind
• Phenomenology: how things seem to a conscious person

Mysteries of Consciousness

• The Problem of Other Minds: fundamental difficulty in perceiving the consciousness of others
• People judge minds based on capacity for experience and capacity for
• The Mind-Body Problem: how the mind is related to the brain and body
• Descartes' view: the pineal gland
• Contemporary view: mental events are intimately tied to brain events

Four Basic Principles of Consciousness

• Intentionality: being directed toward an object
• Unity: resistance to division
• Selectivity: capacity to include some objects but not others
• Transience: tendency to change

Levels of Consciousness

• Consciousness ranges in levels from minimal to full to self-consciousness
• Minimal consciousness
• Full consciousness
• Self-consciousness

Suppressing Thoughts

• Mental control: attempts to change conscious states of mind
• Thought suppression: conscious avoidance of a thought
• Rebound effect of thought suppression: tendency of a thought to return to consciousness with increased frequency following suppression

The Unconscious Mind

• Dynamic unconscious: an active system encompassing lifetime memories, deepest instincts and desires, and inner struggle to control these forces
• Freudian slips found in speech
• Repression: mental process that removes unacceptable thoughts and memories from consciousness

A Modern View of the Cognitive Unconscious

• Cognitive unconscious: all mental processes that give rise to a person's thoughts, choices, emotions, and behaviour
• Dual process theories: two different systems (fast, automatic and unconscious processing; and slow, effortful and conscious processing)
• Kahneman (2001): Systems 1 and 2

Sleep and Dreaming

• Altered state of consciousness: a form of experience that departs from normal subjective experience of the world and the mind
• Can be accompanied by changes in thinking, disturbances in sense of time, feelings of loss of control, and changes in emotional expression
• Alterations in body image and sense of self; perceptual distortions; and changes in meaning or significance

Sleep

• Adaptive theory of sleep: sleep as an evolutionary outcome of self-preservation
• Restorative theory of sleep: sleep that allows the brain and body to restore certain depleted chemical resources while eliminating chemical wastes

Sleep Cycle

• Circadian rhythm: naturally occurring 24-hour cycle
• Brain shows EEG changes in beta, alpha, theta, and delta waves
• Five stages of sleep (stages 1-4 and REM sleep)
• REM sleep: a stage characterized by rapid eye movements and high brain activity
• Dreaming occurs most often in REM stage
• Body becomes immobilized
• EOG (electrooculograph): instrument that measures eye movements

Sleep Needs and Deprivation

• Across a lifetime, about an hour of sleep is needed for every two hours awake
• Memories deteriorate unless sleep occurs
• REM sleep deprivation has the most detrimental effects, followed by slow-wave sleep (stages 3 and 4) deprivation

Sleep Disorders

• Insomnia: difficulty in falling asleep or staying asleep
• Sleep apnea: person stops breathing for brief periods while asleep
• Somnambulism (sleepwalking): occurs when a person arises and walks around during sleep
• Narcolepsy: disorder with sudden sleep attacks in the middle of waking activities
• Sleep paralysis: experience of waking up unable to move
• Night terrors (sleep terrors): abrupt awakenings with panic and intense emotional arousal

Dreams

• Characteristics distinguishing dreaming from waking consciousness: intense emotion, illogical thought, meaningful sensation, uncritical acceptance, and difficulty remembering dreams on waking

Dream Theories

• Freud's view: dreams have meaning
  • Manifest content: dream's apparent topic or superficial meaning
  • Latent content: dream's true underlying meaning
• Activation-synthesis model: brain imposes meaning on random neural activity
• Theory explaining dreams as brain attempting to make sense of random activation during sleep
• fMRI scans of brains during dreaming show increased activity in brain areas involved with emotion and visual imagery, but not in the prefrontal cortex (planning)

Drugs and Consciousness

• Levels of involvement in substance use, including intoxication, abuse, dependence, tolerance, withdrawal, and addiction; physical vs. psychological dependence
• Depressants: substances that slow down or curb activity of the central nervous system (reduces feelings of anxiety, slows movement, and impairs cognitive processes, high doses can cause death) · Alcohol: the 'king' of depressants, and effects can be influenced by expectations (expectancy theory and balanced placebo design) · Alcohol myopia: condition where alcohol hampers attention leading people to respond in simple ways to complex situations
• Barbiturates: sleeping aids and surgical anestheticts (Seconal and Nembutal); Less common than alcohol, but still used and abused
• Benzodiazepines: minor tranquilizers like Valium and Xanax
• Toxic inhalants: easily accessible substances (glue, hairspray, nail polish remover, gasoline)
• Stimulants: drugs that excite central nervous system, heighten arousal, and increase activity levels · Examples: caffeine, amphetamines, nicotine, cocaine, modafinil (and Ecstacy = MDMA) · Stimulants elicit euphoria and confidence/motivation
• Narcotics (opiates): highly addictive drugs derived from opium that relieve pain (e.g., heroin, morphine, methadone, codeine); closely related to endorphins
• Hallucinogens: drugs that alter sensation and perception; often cause visual and auditory hallucinations (examples: LSD (acid), mescaline, psilocybin, PCP, and ketamine)
• Marijuana: leaves and buds of hemp plant containing tetrahydrocannabinol (THC); produces mild hallucinogenic intoxication; impairs judgment, short-term memory, motor skills, and coordination; considered a gateway drug (with alcohol and tobacco)