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Week 5 Modules - Consciousness and Sleep

Consciousness: Awareness

  • Consciousness is difficult to define, similar to concepts like energy, space, or life.

  • Loosely defined as our awareness of ourselves and our environment.

Stream of Consciousness

  • Allows us to process information from various sources.

  • William James described it as a continuously moving stream.

  • Analogy: A flashlight beam shifting focus.

  • Conscious experience is constantly changing.

  • Enables contemplation, future planning, and reflection.

  • Exists in various states: waking, sleeping, and altered states.

Cognitive Neuroscience and Neuroimaging

  • Cognitive neuroscience: Study of brain activity linked to mental processes.

  • Uses neuroimaging to connect brain states and conscious experiences.

  • Structural imaging: Shows brain anatomy, useful for identifying tumors and injuries.

  • Functional imaging: Shows electromagnetic or metabolic activity, revealing correlations between mental functions and brain areas.

  • Neuroimaging is revolutionizing psychology, similar to telescopes in astronomy and microscopes in biology.

  • Important note: Correlation does not equal causation.

Dual Process Models of Consciousness

  • Thoughts and emotions can be illustrated by brain activity.

  • Dual process models: Conscious deliberate mind and implicit automatic mind.

  • Example: Noticing a squirrel.

    • Conscious mind: "Look, a squirrel"

    • Implicit mind: processes color, size, distance, associations, and biases.

Selective Attention

  • We receive 11,000,000 bits of information per second but only consciously register 40.

  • Selective attention: Focusing on one stimulus and tuning out others.

  • Analogy: A spotlight on a stage.

  • Example: Noticing socks on feet or the tongue in your mouth only when mentioned.

  • Cocktail party effect: Concentrating on one conversation amidst noise.

  • But hearing your name grabs your attention.

  • Danger of divided attention: Texting while driving activates selective inattention, leading to missed observations.

Inattentional Blindness

  • Failure to notice obvious things when attention is directed elsewhere.

  • Invisible gorilla experiment: 50% of people missed a gorilla walking through the scene because they were focused on counting passes.

  • Magicians Uses of Inattentional Blindness - Misdirection

    • "Every time you perform a magic trick, you're engaging in experimental psychology, and we can't help but be the rubes"

Change Blindness

  • Failure to notice changes in the environment.

  • Example: Person swap experiment where a person doesn't notice that the person they are talking to has been replaced by a different person.

  • Can be dangerous in situations like faulty memories leading to false testimonies.

  • Bottom line: We are less aware than we think.

Sleep and Dreams

  • Sleep is a state of consciousness, not dormancy.

  • Sleep: Periodic, natural, reversible, near-total loss of consciousness.

Why We Sleep

  • Recuperation: Neurons repair themselves.

  • Growth: Pituitary glands release growth hormones.

  • Benefits: Improves memory, processes events, boosts creativity.

Stages of Sleep

  • Identified using EEG (electroencephalograph).

  • Eugene Asarinsky discovered REM sleep.

  • Four stages of sleep, each with unique brainwave patterns.

    • Awake: Alpha waves.

    • NREM-1: Irregular waves, hypnagogic sensations (falling feeling).

    • NREM-2: Sleep spindles (bursts of activity), easily awakened.

    • NREM-3: Slow delta waves.

    • REM: Rapid eye movement, vivid dreams, motor cortex active but muscles paralyzed.

  • Cycle repeats every 90 minutes.

Importance of Sleep

  • Lack of sleep: bad for health, mental ability, and mood.

  • Predictor for depression, linked to weight gain, immune suppression, and slowed reaction time.

Sleep Disorders

  • Insomnia: Difficulty falling/staying asleep.

  • Narcolepsy: Uncontrollable sleep attacks, possibly due to hypocretin deficiency.

  • Sleep apnea: Temporary cessation of breathing during sleep.

  • REM sleep behavior disorder: Associated with dopamine deficiency.

  • Night terrors: Screaming and thrashing, common in children, occur during NREM-3.

Dreams

  • Vivid, emotional images during sleep.

  • Average person spends six years of their life dreaming.

  • Dreams unpack and reshuffle daily events.

  • Traumatic events lead to nightmares.

  • Two-track minds register stimuli during the day which appear in dreams.

Theories of Dreaming

  • Onyrology: The study of dreams.

  • Freud's wish fulfillment theory: Dreams offer wish fulfillment, with manifest content symbolizing latent content (lacks scientific support).

  • Information processing theory: Dreams help sort and process events, fixing them into memories.

  • Physiological function theory: Dreaming promotes neural development and preserves pathways.

  • Cognitive development theory: Dreams draw on knowledge and mimic reality.

  • Neural activity theories: Dreams are accidental side effects of the brain trying to make sense of random neural activity.