Chapter 14 - Sleep Flashcards
The three standard psychophysiological bases for defining stages of sleep.
Electroencephalogram (EEG), electrooculogram (EOG), and electromyogram (EMG).
First-night phenomenon
The disturbance of sleep observed during the first night in a sleep laboratory. Often fitful. Because of this, usual practice is to have participants sleep several night in laboratory before commencing sleep study.
Alpha waves
8- to 12-Hz EEG waves.
K complex
A single large negative wave (upward deflection) followed immediately by a single large positive wave (downward deflection).
Sleep spindle
A 1- to 2-second waxing and waning burst of 12- 14-Hz waves.
Delta waves
The largest and slowest EEG waves, with a frequency of 1 to 2 Hz.
Stage 3 of sleep EEG
Defined by the occasional presence of delta waves.
Stage 4 EEG sleep
Defined by a predominance of delta waves.
Each sleep cycle tends to be about _______ long.
90 minutes
Once sleepers reach stage 4 EEG sleep, they stay there for a time, and then retreat back through the stages of sleep to stage ____.
1
The first period of stage 1 EEG during a night’s sleep (called ______) is not marked by any striking electromyographic or electrooculographic changes, whereas subsequent periods of stage 1 sleep EEG (called ______) are accompanied by ______ and by a ________ of the body core.
Initial stage 1 EEG,
Emergent stage 1 EEG,
REMs,
loss of tone in the muscles.
After the eyes are shut and a person prepares to go to sleep, ______ begin to punctuate the low-voltage, high frequency waves of alert wakefulness.
Alpha waves
The stage _____ sleep EEG is a low-voltage, high frequency signal that is similar to, but slower than, that of alert wakefulness.
1
The two kinds of theories proposed for sleep:
- Recuperation
- Adaptation
Recuperation theories of sleep
Being awake disrupts the homeostasis of the body in some way and sleep is required to restore it.
Homeostasis
Internal physiological stability
Adaptation theories of sleep
Sleep is not a reaction to the disruptive effects of being awake, but the result of an internal 24-hour timing mechanism– that is, we humans are programmed to sleep at night regardless of what happens to us during the day. According to these theories, we have evolved to sleep at night because sleep protects us from accident and predation during the night.
Adaptation theories of sleep focus more on _____ we sleep rather than on the _____ of sleep.
when,
function.
Even moderate amount of sleep deprivation have been found to have three consistent effects:
- increased sleepiness.
- display negative affect on various written mood tests (grumpier).
- perform poorly on tests of vigilance, such as watching a computer screen and responding when a moving light flickers.
Executive function
Innovative thinking, lateral thinking, insightful thinking, assimilating new information to update plans and strategies. Cognitive abilities that appear to depend on the prefrontal cortex.
Microsleeps
Brief periods of sleep, typically about 2 or 3 seconds long, during which eyelids droop and the volunteers become less responsive to external stimuli, even though they remain sitting or standing.
Many early studies of the effect of sleep deprivation on cognitive function used tests of _______ or ______, and performance on these has proved to be largely immune to the disruptive effects of sleep loss.
Logical deduction,
Critical thinking.
The carousel apparatus kills rats after approximately 12 days of keeping the rats from sleeping. Another explanation for their death could be _______.
Stress
REM-sleep deprivation has shown to have two consistent effects:
- participants display a REM rebound (they have more than their usual amount of REM sleep for the first two or three nights).
- with each successive night of REM deprivation, there is a greater tendency for participants to initiate REM sequences.