Key Terms

Module 8.1

  • Endogenous Circadian Rhythms: Internal biological clocks that regulate sleep-wake cycles, roughly following a 24-hour period.

  • Endogenous Circannual Rhythm: Biological rhythms that occur annually, such as seasonal behaviors or reproductive cycles.

  • Jet Lag: Disruption of biological rhythms due to crossing multiple time zones, causing sleep disturbances and fatigue.

  • Melatonin: A hormone primarily released by the pineal gland that regulates sleep-wake cycles and is influenced by light exposure.

  • Pineal Gland: A small endocrine gland in the brain that produces melatonin and regulates circadian rhythms.

  • Suprachiasmatic Nucleus: A group of neurons in the hypothalamus that serves as the primary regulator of circadian rhythms.

  • Zeitgeber: Any external cue, such as light or temperature, that influences the biological clock and helps synchronize circadian rhythms.

Module 8.2

  • Alpha Waves: Brain wave patterns associated with relaxed but awake states, typically seen in the resting stage of wakefulness.

  • Basal Forebrain: A region of the brain involved in sleep regulation and arousal.

  • Brain Death: A medical diagnosis where there is irreversible loss of all functions of the brain, including the brainstem.

  • Coma: A state of prolonged unconsciousness where a person cannot be awakened and does not respond to stimuli.

  • Insomnia: A sleep disorder characterized by difficulty falling asleep, staying asleep, or waking up too early.

  • K-complex: A waveform seen on EEG that occurs during NREM sleep, often triggered by external stimuli.

  • Locus Coeruleus: A small area in the brain responsible for physiological responses to stress and panic, playing a role in sleep regulation.

  • Minimally Conscious State: A condition of severely altered consciousness with some measurable awareness and variability in response to stimuli.

  • Narcolepsy: A sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks.

  • Night Terror: A sleep disturbance characterized by episodes of screaming, intense fear, and panic during sleep, typically occurring in NREM sleep.

  • Non-REM (NREM) Sleep: A phase of sleep that does not involve rapid eye movement, divided into different stages including light and deep sleep.

  • Orexin: A neurotransmitter involved in regulating arousal, wakefulness, and appetite, playing a crucial role in sleep disorders.

  • Paradoxical Sleep: Another term for REM sleep where the brain is very active, but the body is in a state of temporary paralysis.

  • Periodic Limb Movement Disorder: A sleep disorder characterized by involuntary flexing and extending of the legs during sleep.

  • PGO Waves: Phasic brain activity that typically occurs during REM sleep, associated with dreaming.

  • Polysomnograph: A comprehensive recording of the biophysiological changes that occur during sleep, used to diagnose sleep disorders.

  • Pontomesencephalon: A part of the brain that plays a role in the regulation of arousal and sleep-wake states.

  • Rapid Eye Movement (REM) Sleep: A stage of sleep characterized by rapid movement of the eyes, increased brain activity, and vivid dreams.

  • REM Behavior Disorder: A condition where individuals act out their dreams during REM sleep due to loss of normal paralysis.

  • Reticular Formation: A network in the brainstem that plays a crucial role in controlling arousal and consciousness.

  • Sleep Apnea: A sleep disorder where breathing repeatedly stops and starts during sleep, leading to reduced oxygen levels and disrupted sleep.

  • Sleep Spindle: Short bursts of brain activity that occur during sleep, thought to be involved in memory processing.

  • Slow-wave Sleep: Stages of deep sleep characterized by delta waves on an EEG, important for restorative processes in the body.

  • Unresponsive Wakefulness Syndrome: Previously known as vegetative state, a condition where a patient is awake but does not show signs of awareness.

Module 8.3

  • Activation-Synthesis Hypothesis: A theory that posits dreams are the brain's attempt to make sense of random neural activity during sleep.

  • Neurocognitive Model: A theory suggesting that dreaming is a process of cognitive development and problem solving that integrates experiences and emotions while asleep.