PSY 340 Chapter 11

Delta Wave

A brain waveform having 1-4 cycles per second that occurs during Stages 3 and 4 of NREM sleep

Beta Wave

A brain waveform having 15-20 cycles per second, associated with high levels of alertness during wakefulness

Theta Wave

A brain waveform having 4-7 cycles per second found primarily in lighter stages of NREM sleep

Alpha wave

A brain waveform having 9-12 cycles per second, associated with less alertness and more relaxation than beta activity during wakefulness

Ultradian Cycle

A cycle that occurs several times in a single day

Cataplexy

A feature of narcolepsy in which REM muscle paralysis intrudes into the waking state

Cortisol

A hormone released by the adrenal glands that promotes arousal.

Rapid-Eye-Movement (REM) Sleep

A period of sleep characterized by desynchronous brain activity, muscle paralysis, eye movement, and story-like dream behavior

Non-REM sleep (NREM)

A period of sleep characterized by slow, synchronous brain activity, reductions in heart rate, and muscle relaxation

Circadian Rhythm

A repeating cycle of about 24 hours

Narcolepsy

A sleep disorder characterized by the intrusion of REM sleep, and occasionally REM paralysis, into the waking state.

Dyssomnia

A sleep disorder that involves difficulty initiating or maintaining sleep

Parasomnia

A sleep disorder that involves the intrusion of unusual behaviors into sleep

Suprachiasmatic Nucleus (SCN)

An area of the hypothalamus located above the optic chiasm; responsible for maintaining circadian rhythms

PGO Spike

An electrical waveform observed during REM sleep, originating in the pons and traveling to the thalamus and occipital cortex. Each PGO wave is associated with an eye movement.

Zeitgerber

An external cue for setting biological rhythms

Melatonin

An indoleamine secreted by the pineal gland that participates in the regulation of circadian rhythms

Desynchronous

Having different periods and phases; in EEG, represents high levels of brain activity

Synchronous

Having identical periods and phases; in EEG, represents relatively low levels of brain activity

Insomnia

The inability to sleep a normal amount of time