Chapter 9 Wakefulness and Sleep Flashcards
Activation-synthesis hypothesis
idea that a dream represents the brain’s effort to make sense of sparse and distorted information
Alpha waves
a steady series of brain waves at a frequency of 8 to 12 per second that are characteristic of relaxation
Basal forebrain
area anterior and dorsal to the hypothalamus; includes cell clusters that promote wakefulness and sleep
Brain death
condition with no sign of brain activity and no response to any stimulus
Clinico-anatomical hypothesis
idea that considers dreams as a type of thinking that occurs under unusual conditions
Coma
an extended period of unconsciousness with a low level of brain activity
Endogenous circadian rhythm
self-generated rhythm that lasts about a day. See also Circadian rhythms
Endogenous circannual rhythm
self-generated rhythm that lasts about a year
Insomnia
inadequate sleep
Jet lag
a disruption of circadian rhythms due to crossing time zones
K-complex
a sharp brain wave associated with temporary inhibition of neuronal firing
Limbic system
interlinked structures that form a border around the brainstem
Locus coeruleus
a small structure in the pons that emits bursts of impulses in response to meaningful events, especially those that produce emotional arousal
Minimally conscious state
condition of decreased brain activity with occasional, brief periods of purposeful actions and limited speech comprehension
Narcolepsy
a condition characterized by frequent periods of sleepiness during the day
Night terrors
experiences of intense anxiety from which a person awakens screaming in terror; more severe than a nightmare
Non-REM (NREM) sleep
stages of sleep other than REM
Orexin (hypocretin)
neurotransmitter that increases wakefulness and arousal
Pineal gland
an endocrine gland located just posterior to the thalamus that releases the hormone melatonin
Polysomnograph
a combination of EEG and eyemovement records
Pons
hindbrain structure that lies anterior and ventral to the medulla
Pontomesencephalon
part of the reticular formation that contributes to cortical arousal
Rapid eye movement (REM) sleep
sleep stage with rapid eye movements, high brain activity, and relaxation of the large muscles
REM behavior disorder
a condition in which people move around vigorously during REM sleep
Sleep apnea
impaired ability to breathe while sleeping
Sleep spindle
12 to 14 Hz brain waves in bursts that last at least half a second
Slow-wave sleep (SWS)
stages 3 and 4 of sleep, which are occupied by slow, large-amplitude brain waves
Suprachiasmatic nucleus (SCN)
part of the hypothalamus; provides the main control of the circadian rhythms for sleep and body temperature
Vegetative state
condition in which someone has decreased brain activity and alternates between wakefulness and sleep but shows only limited responsiveness, such as increased heart rate in response to a painful stimulus
Zeitgeber
stimulus that resets the circadian rhythm
Paradoxical sleep
sleep that is deep in some ways and light in others
Periodic limb movement disorder
a sleep disorder characterized by repeated involuntary movement of the legs and sometimes the arms
PGO waves
a distinctive pattern of high-amplitude electrical potentials that occur first in the pons, then in the lateral geniculate, and then in the occipital cortex