Lecture 8 Flashcards
What are biological rhythms?
Periodic fluctuations in physiological functioning
Examples include alertness levels throughout the day.
What are circadian rhythms?
The 24-hour biological cycles found in humans and many other species.
What is the role of the suprachiasmatic nucleus (SCN) in sleep?
Receives input from the retina and sends signals to the pineal gland to regulate melatonin release.
What hormone regulates sleep-wake cycles?
Melatonin.
What causes jet lag?
A temporary disruption of circadian rhythms and sleep patterns caused by rapid travel across time zones.
What is consciousness?
The awareness of internal and external stimuli.
What is an electroencephalogram (EEG)?
A device that monitors the electrical activity of the brain over time.
What are brainwaves?
Electrical patterns in the brain measured with EEG.
What frequency range characterizes beta brainwaves?
13-24 Hz.
What characterizes alpha brainwaves?
8-12 Hz; associated with relaxation and meditation.
What is the frequency range for theta brainwaves?
4-7 Hz; indicates light sleep.
What is the frequency range for delta brainwaves?
0.5-4 Hz; indicates deep sleep.
What is polysomnography (PSG)?
A comprehensive sleep study that simultaneously records various physiological factors.
What characterizes Stage 1 sleep?
Transition between wakefulness and deeper sleep, lasts 5-10 minutes.
What are sleep spindles?
Bursts of 12-16 Hz activity during Stage 2 sleep.
What is the deepest stage of sleep?
Stage 3 sleep (slow-wave sleep).
What is REM sleep characterized by?
Complete muscle paralysis, rapid eye movements, and mixed EEG frequencies resembling wakefulness.
What is a hypnogram?
A graph of one’s sleep stages across the night.
How often do people cycle through all sleep stages during a night?
Approximately every 90 minutes.
What is the day-residue effect in dreaming?
Recent daily experiences can influence dream content on the same night.
What does the Activation-Synthesis Hypothesis suggest about dreaming?
Dreams arise from the brain’s attempt to interpret random neural activity during REM sleep.
What is narcolepsy?
A chronic sleep disorder characterized by excessive daytime sleepiness and sudden sleep episodes.
What are night terrors?
Intense, abrupt episodes of fear during sleep, often without recollection upon waking.
What is sleep apnea?
Recurrent pauses in breathing during sleep.
What characterizes insomnia?
Difficulty falling asleep, staying asleep, or experiencing non-refreshing sleep.
What is Fatal Familial Insomnia?
A rare inherited disease leading to inability to sleep, resulting in cognitive decline and death.
What is REM Behaviour Disorder?
The absence of normal muscle paralysis during REM sleep, causing individuals to act out dreams.
What is the function of dreams according to Threat Simulation Theory?
To rehearse threatening situations.
Fill in the blank: The hormone _______ regulates sleep-wake cycles.
Melatonin.
True or False: Nightmares occur during REM sleep.
True.
True or False: Sleepwalkers typically have no memory of their actions.
True.
