5.2: Sleep Flashcards
Circadian Rhythms
The regulation of biological cycles into regular patterns. Body temperature, hormone levels and sleep/wake cycles operate according to circadian rhythms. Influenced by cycles of light and dark
Beta waves
Short, frequent irregular waves that show up on an EEG during wakefulness when people have many sources of sensory activity and neurons in their brain are extremely active.
Alpha waves
Waves that show up on an EEG when people focus their attention or relax, causing brain activity to slow and become more regular
Sleep Stage 1
First stage of sleep from which you can be easily woken, and may not know you were sleeping. Light, and might cause you to see fantastical images or geometric shapes. Produces theta waves on an EEG
Sleep Stage 2
Breathing becomes more regular, you are less sensitive to external stimulation. EEG shows theta waves, but also bursts called sleep spindles and waves called K-complexes. May be involved in shutting out external stimulus to keep you asleep
Sleep Stage 3/4
Produces delta waves on EEG: large, regular brain patterns. Often called slow-wave sleep. People in slow-wave sleep are hard to wake up, but mind continues to evaluate environment for potential danger
REM Sleep
Stage of sleep marked by rapid eye movement, dreaming, and paralysis of motor systems. Sleep cycle is returning to Stage 1. Brain is very active.
Insomnia
A disorder characterized by the inability to sleep. Can be highly detrimental to psychological well-being
Obstructive Sleep Apnea
A disorder in which a person, while asleep, stops breathing because his or her throat closes; the condition results in frequent awakenings during the night.
Narcolepsy
Sleep disorder in which people experience excessive sleepiness during normal waking hours, sometimes going limp and collapsing
REM Behavior Disorder
Disorder in which normal paralysis that accompanies REM sleep is disabled, so sufferers act out their dreams while sleeping
Three proposed general explanations for sleeps adaptiveness
restoration, circadian rhythms, and facilitation of learning.
Restorative Theory
Says that sleep allows the body, including the brain, to rest and repair itself
Circadian Rhythm Theory
Proposes that sleep has evolved to keep animals quiet and inactive during times of the day when there is greatest danger, usually when it is dark
Sleep and Facilitation of Learning
Scientists have proposed that sleep is important because it is involved in the strengthening of neural connections that serve as the basis of learning. Idea is that circuits that wired together during the waking period are strengthened during sleep.
