Modules 1.5 & 1.6: Consciousness, Sleep, and Sensation

Vocabulary flashcards covering consciousness, dual processing, sleep stages and disorders, dream theories, and foundational sensation and perception concepts.

Consciousness

Being aware of yourself and your surroundings.

Dual Processing

The brain's ability to process information on two separate levels (tracks) at the same time.

The High Road (Conscious)

Deliberate, fully focused attention, such as solving a difficult math problem.

The Low Road (Unconscious)

Automatic processing without having to consciously think, such as ducking when a ball is thrown at you.

Blindsight

A condition where a person is visually blind but can still respond to visual stimuli without consciously seeing them.

Parallel Processing

Processing multiple aspects of a situation or problem all at the same time.

Sequential Processing

Processing information step-by-step, one thing at a time.

Circadian Rhythm

Your body's internal $24\text{-hour}$ clock that regulates sleepiness and wakefulness.

Suprachiasmatic Nucleus (SCN)

A structure in the hypothalamus that tracks light/darkness and controls sleep by signaling melatonin levels.

Melatonin

A sleep-inducing hormone released in response to darkness.

Beta Waves

EEG brain waves produced when a person is awake, alert, fully conscious, and actively paying attention.

Alpha Waves

EEG brain waves produced when resting with eyes closed and drifting off in an awake and relaxed state.

NREM-1 (N1)

A sleep stage characterized by transition waves, hypnagogic sensations (feeling like falling/floating), and mild hallucinations.

NREM-2 (N2)

A moderate sleep stage where it is easy to wake up, characterized by sleep spindles on the EEG.

NREM-3 (N3)

A deep sleep stage lasting approximately $30\text{ mins}$ characterized by delta waves where it is hard to wake up.

REM Sleep

A sleep stage characterized by vivid dreaming, rapid eye movement, increased heart rate, and active/beta-like waves.

Paradoxical Sleep

Another term for REM sleep referring to the state where the brain is super active, but the body's muscles are completely relaxed/paralyzed.

Insomnia

A sleep disorder marked by chronic trouble falling asleep or staying asleep.

Narcolepsy

A sleep disorder characterized by sudden, uncontrollable 'sleep attacks' during the day.

Sleep Apnea

A sleep disorder involving momentarily stopping breathing repeatedly during sleep, causing loud snoring and waking up gasping.

Sleepwalking (Somnambulism)

Walking or moving around during NREM-3 deep sleep, which is more common in children.

REM Sleep Behavior Disorder

A disorder where a person physically acts out vivid or violent dreams due to a lack of normal muscle paralysis during REM.

Information Processing Theory

A dream theory proposing that dreaming helps sort, organize, and consolidate the day's memories.

Physiological Function Theory

A dream theory suggesting that regular brain stimulation during REM helps develop and preserve neural pathways.

Activation-Synthesis Theory

A dream theory proposing that the brain attempts to make sense of random neural activity occurring during sleep.

Cognitive Development Theory

A dream theory stating that dream content reflects the dreamer's level of mental maturity and knowledge.

Sensory Receptors

Specialized cells or nerve endings that capture signals from the outside world.

Sensation

Receptors receiving raw energy/data from the environment.

Perception

The brain organizing and interpreting sensory data into meaningful experiences.

Bottom-Up Processing

Processing that starts with raw sensory data from the stimulus and builds up to perception.

Top-Down Processing

Processing that uses background knowledge, expectations, and experience to interpret sensory information.

Absolute Threshold

The minimum amount of stimulus energy needed to detect a stimulus $50\%$ of the time.

Difference Threshold (Just-Noticeable Difference / JND)

The minimum difference between two stimuli required to detect a change $50\%$ of the time.

Weber’s Law

The principle that to perceive a difference, two stimuli must differ by a constant percentage rather than a fixed amount.

Sensory Adaptation

Diminished sensitivity as a result of constant, unchanging stimulation.

Subliminal Messages

Sensory stimuli that fall below your conscious absolute threshold.