Sleep

consciousness

the awareness of external stimuli and our own mental activity

Electrocencephalograph (EEG)

Monitors brain waves

William Dement

father of sleep medicine

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

ultradian rhythms

biological rhythms that occur more than once each day

Jet lag

Your biological clock keeps time as usual even though the official clock time changes

suprachiasmatic nucleus

a cluster of neurons in the hypothalamus in the brain that governs the timing of circadian rhythms and releases neurotransmitters

Adenosine

Neurotransmitter that triggers sleepiness

Melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

Pons

Involved in REM sleep, sends signal to shut off spinal cord

Thalamus

Helps us tune out sensory signals during sleep

alpha waves

slow brain waves of a relaxed, awake state

beta waves

awake and alert

delta waves

deep sleep

Stages of NREM sleep: Stage 1

Irregular brain waves, slowed breathing, hypnagogic sensations

hypnagogic sensations

life-like hallucinations that occur shortly after falling asleep; usually sensation of falling or floating

Stages of NREM sleep: Stage 2

Sleep spindles, sleep talking, could be awakened without difficulty, 50% of night here

sleep spindles

bursts of rapid, rhythmic brain-wave activity

Stages of NREM sleep: Stage 3

Deep sleep, delta waves, sleep walking, hard to waken

REM sleep

the stage of sleep marked by rapid eye movements, dreaming, and paralysis of motor systems

With each 90-minute cycle, stage 3 sleep ____ and the duration of REM sleep ____.

Decreases, increases

Insomnia

Difficulty in falling asleep or staying asleep

REM rebound

increased amounts of REM sleep after being deprived of REM sleep on earlier nights

Apnea

Airway is blocked during sleep, difficulty breathing

somnambulism

sleepwalking

Narcolepsy

sudden attacks of overwhelming sleepiness

REM sleep behavior disorder

a neurological disorder in which the person does not become paralyzed during REM sleep and thus acts out dreams

What disorder is RBD associated with?

Parkinson's

Why do we need sleep?

protection, recuperation, restore and rebuild memories, creativity, growth

activation-synthesis theory

REM sleep triggers random visualizations and our mind makes a story out of it

consolidation theory

Sleep and dreams help to consolidate and strengthen memories

psychoactive drugs

a chemical substance that alters perceptions, mood, or behavior through their actions at the neural synapse

types of psychoactive drugs

caffeine, alcohol, nicotine

Depressants

drugs that reduce neural activity and slow body functions

effects of alcohol

slowed down reactions and judgment, impaired motor coordination

Stimulants

drugs that excite neural activity and speed up body functions

Caffeine

a stimulant drug found in coffee, tea, cola drinks, chocolate that blocks neurological receptor sites

Hallucinogens

distort perceptions and evoke sensory images in the absence of sensory input

Marijuana

THC is an agonist that triggers release of other neurotransmitters

Tolerance

Diminished effects of the same dose of a drug

addiction

compulsive drug craving and use, despite adverse consequences

Dependence

the need to take a substance to avoid physical discomfort

Withdrawal

negative reaction that occurs when drug use is stopped