PSYC 2200 Reading 15

automatism

involuntary complex response that occurs outside of conscious awareness

electroencephalograms

tests that track and record the electrical activity of the brain using electrodes attached to the scalp, a primary tool for investigating the biological basis of sleep

parasomnias

talking, walking, and eating during sleep

circadian rhythms

responses, such as the timing of sleep and wake cycles, with distinct daily rhythms

zeitgeber

german for time-giver, events such as daylight, alarm clocks, city sounds, and voices of family members that regulate or synchronize rest and activity cycles (light is the strongest zeitgeber)

free-running rhythms

internal mechanisms that regulate daily rest and activity cycles

suprachiasmatic nucleus

nucleus of the hypothalamus that receives stimulation from light via tracts extending from the retina (retinohypothalamic tracts)

ultradian rhythms

biological rhythms with a period shorter than 24 hours (not under SCN control)

melatonin

hormone produced by the pineal gland that is involved in sleep-wake cycles

jet lag

sleep problems resulting from desynchronization of biological rhythms

shift work

employment that requires employees to periodically change their work hours around the clock on a rotating basis

sleep

reversible state characterized by minimal movement, a relaxed posture, and diminished attention directed to the environment

polysomnography

physiological recording technique that simultaneously records brain wave activity, eye movements, and muscle tension

polysomnograph

records of polysomnography

electrooculogram

assesses eye movements

eletromyogram

assessing muscle tension, typically under the chin

beta waves

most active waves - fast (13-30 Hz), irregular, low-intensity waves that typically occur in brains that are awake and active

alpha waves

fairly regular, consistently shaped, and slightly slow (8-12 Hz) brain waves that are predominant in awake, but drowsy, brains

theta waves

low intensity, slow (3-7 Hz) brain waves of the sleeping brain

delta waves

low frequency sleep waves (0.5-3 Hz), characteristic of slow wave sleep

k-complexes

large waves with a slow rise to a peak followed by a faster decline, characteristic of stage 2 EEGs

sleep spindles

characteristic of stage EEGs, moderately fast and intense oscillations (12-14 Hz) that last up to 1.5 seconds

non-REM sleep

a stage of night sleep, composed of 3 stages

stage 1 sleep

initial phase of non-REM sleep characterized by a transition from beta waves to alpha waves, relaxing muscles, and slow eye movements

stage 2 sleep

phase of non-REM sleep characterized by the appearance of k-complexes and sleep spindles and a lack of eye movements

slow wave sleep

sleep dominated by low-frequency delta waves and extreme grogginess

hibernation

form of prolonged sleep on a seasonal rhythm found in some animals, enhances survival by allowing withdrawal from harsh environmental conditions

torpor

physiological state characterized by modifications in body temperature, metabolism, and fluid regulation to accommodate restricted or inhabitable environments; shorter than hibernation states