Consciousness, Self, and Sleep: Exam Notes

Consciousness: Introduction

  • Study of Consciousness: Crucial for understanding human existence and the universe, pushing limits of natural sciences.

  • Mind-Body Problem (Philosophy): How does physical matter (brain) generate private, non-material consciousness?

    • Dualism: Mind and body are distinct substances (e.g., Plato, Descartes). Faces the "interaction problem". Major religions are often dualist.

    • Monism: Only one kind of reality.

      • Idealism: Mind is fundamental.

      • Neutral Monism: Mental and physical are representations of a single neutral reality.

      • Materialism: Matter is fundamental (most popular among scientists).

The Hard Problem

  • Definition: How physical processes in the brain give rise to subjective experience. Modern version of the mind-body problem.

  • Explanatory Gap: Chasm between material brain and subjective experience.

  • Easy Problems: Perception, learning, memory, attention, sleep (according to Chalmers). Many argue these are underestimated or that no hard problem exists.

  • Subjectivity: Consciousness is a private, subjective experience (e.g., "What is it like to be a bat?" - Nagel). Physical information alone may not explain subjective experience (Tracy’s Red1/Red2 experiment).

  • Qualia: Introspectively accessible, phenomenal, private aspects of mental life (e.g., the redness of red). At the heart of the mind-body problem.

Defining Consciousness

  • No Agreed Definition: Defined as awareness, awake state, totality of thoughts/feelings.

  • Awareness: Experience of perceiving a sensation.

  • Self-consciousness: Awareness of one's own awareness.

  • Fundamental Private Experience: Cannot explain one's experience to others; certainty that others have conscious experience is not possible.

  • Philosophical Zombies: Hypothetical beings physically identical to humans but lacking qualia/conscious experience. Their logical possibility challenges pure materialism.

  • Alternative Views: Consciousness is identical to physical brain processes; consciousness is an illusion; consciousness is an additional, functional quality.

  • Panpsychism: Consciousness pervades the universe; every sufficiently complex system is conscious (e.g., Integrated Information Theory (IIT) by Tononi, with ext{Phi} score).

The Self

  • Definition: The "I" that experiences the world, perceived as identity, often believed to be constant.

  • William James: Distinguished "I" (experiencing self) and "me" (perceived self).

  • Self-Awareness: Capacity to observe one's own internal milieu via introspection.

  • Rouge Test: Measures self-recognition in children and some animals.

  • Self Theories:

    • Ego Theory: A single, unified "me" (Ego) persists over time, unifying consciousness.

    • Bundle Theory: No inherent self, just a sequence of mental states creating an illusion of self (similar to Buddhist concept of annattā). (Example: Ship of Theseus).

    • Knower and Known: "I" (minimal self, agency, ownership) versus "me" (narrative self, autobiographical memory, story of oneself).

    • Self as a Construction: Self is an abstraction, a "center of narrative gravity" (Dennett), dynamically constructed based on context and memory (Markus & Wurf's Dynamic Self Concept).

Sleep

  • Brain and Consciousness: Consciousness linked to brain activity, correlated with brain waves.

  • Brain Waves (EEG):

    • Beta Waves: Alert, active thinking, REM sleep ( 12-30 Hz).

    • Alpha Waves: Relaxed, normal alert consciousness ( 8-12 Hz).

    • Theta Waves: Creativity, insight, light NREM sleep ( 4-7 Hz).

    • Delta Waves: Slow wave/deep NREM sleep ( 0.5-4 Hz).

  • Sleep Stages (approximately 90 minute cycles):

    • Stage 1 (NREM): 5-10 mins, alpha to theta waves, hypnagogic imagery.

    • Stage 2 (NREM): 10-30 mins, sleep spindles, K-complexes, 65% of total sleep.

    • Stages 3 & 4 (NREM): 15-30 mins, delta waves (SWS), crucial for feeling rested.

    • Stage 5 (REM): 10-20 mins, brain activity like wakefulness, vivid dreams, longer as night progresses.

  • Sleep Functions: Restorative, crucial for cognition and survival. REM sleep functions (memory, forgetting, insight) are debated.

  • Circadian Rhythm: 24 -hour cyclical changes (hormones, body temperature, brain waves).

    • Regulated by suprachiasmatic nucleus (SCN) in the hypothalamus.

    • SCN triggers melatonin increase, causing fatigue.

    • Photosensitive retinal ganglion cells (pRGCs), sensitive to blue light ( 470-480 nm), connect to SCN and modulate sleep/alertness.