Biopsychology Final Exam Review
Sleep:
Zeitgeber: Environmental cues that entrain circadian rhythms.
Recuperative and circadian theories of sleep
- Recuperative: Being awake disrupts homeostasis and sleep restores it.
Two most common recuperation theories of sleep are that the function of
sleep is to restore energy levels that decline during wakefulness and to
clear toxins
- Circadian: Sleep plays no role in physiological functioning. We become
tired when it is dark out (based on an internal timing mechanism…sleep-
wake cycle. Sleep conserves energy
Anatomical location of the circadian clock and related genes ***
- The circadian clock is located at the Suprachiasmatic nucleus (SCN) of
the medial hypothalamus
EEG, EOG, EMG (Ways of measuring sleep)
- EEG: Electroencephalogram- record of the electrical activity of the
brain…waves generally high-voltage and slow during sleep
- EOG: Electrooculogram- an instrument that measures eye movements/
activity in the eyes
- EMG: Electromyogram- measures activity in the muscles of the body
core during these same sleep periods
Three Stages/ Phases of Sleep
- Before a subject falls asleep (ALPHA waves, large-amplitude and
regular)
- Stage 1: as a person falls asleep, there is a sudden transition to stage 1.
Low-voltage, high-frequency that is similar to, but slower than, that of
alert wakefulness (THETA waves, low-voltage, fast activity)
- Stage 2: gradual increase in voltage and decrease in frequency moving
into stage 2.
K complexes: large negative wave followed by large positive
wave
Sleep spindles: 1 to 2 second waxing/waning burst
, - Stage 3: DELTA waves largest and slowed EEG waves – largest voltage
low frequency
- Emergent state: Cycle goes back to stage 1
Recognizing sleep waves
, Characteristics of REM sleep
- Rapid Eye Movements (REM) occur under the eyelids in sleep
- Characteristics include REMs, loss of core-muscle tone, and a low-
amplitude, high-frequency EEG
- Cerebral firing increases, etc.
- 80% of awakenings from REM sleep led to dream recall (external
stimuli incorporated into dreams, run on real time, etc.)
Somnambulism and dreaming (which phase)
- Somniloquy: sleep talking
- Somnambulism: sleepwalking
- Sleep talking can occur at any phase of sleep
- Sleepwalking usually occurs during slow-wave sleep (stage 3), and it
NEVER occurs during REM sleep
Consequences of sleep deprivation
- Most people who are sleep deprived as so because of stress
- Prediction: Excessive wakefulness results in debilitating physiological
deficits, which will worsen with more sleep deprivation
- Results: no marked physiological disturbances, sleepiness, mood
disturbances, problems maintaining vigilance, micro sleeps, poor
executive function
Insomnia & Hypersomnia
- Insomnia: too little undisturbed sleep, can be iatrogenic, delayed falling
asleep, only 4 ½ hours of sleep, not staying asleep,
sleep restriction as a treatment
Causes include sleep apnea (either obstructive or central), periodic
limb movement syndrome, restless leg syndrome
- Hypersomnia: excessive/ inappropriate sleep
Narcolepsy
The orexin gene that promotes wakefulness is reduced
Sleep:
Zeitgeber: Environmental cues that entrain circadian rhythms.
Recuperative and circadian theories of sleep
- Recuperative: Being awake disrupts homeostasis and sleep restores it.
Two most common recuperation theories of sleep are that the function of
sleep is to restore energy levels that decline during wakefulness and to
clear toxins
- Circadian: Sleep plays no role in physiological functioning. We become
tired when it is dark out (based on an internal timing mechanism…sleep-
wake cycle. Sleep conserves energy
Anatomical location of the circadian clock and related genes ***
- The circadian clock is located at the Suprachiasmatic nucleus (SCN) of
the medial hypothalamus
EEG, EOG, EMG (Ways of measuring sleep)
- EEG: Electroencephalogram- record of the electrical activity of the
brain…waves generally high-voltage and slow during sleep
- EOG: Electrooculogram- an instrument that measures eye movements/
activity in the eyes
- EMG: Electromyogram- measures activity in the muscles of the body
core during these same sleep periods
Three Stages/ Phases of Sleep
- Before a subject falls asleep (ALPHA waves, large-amplitude and
regular)
- Stage 1: as a person falls asleep, there is a sudden transition to stage 1.
Low-voltage, high-frequency that is similar to, but slower than, that of
alert wakefulness (THETA waves, low-voltage, fast activity)
- Stage 2: gradual increase in voltage and decrease in frequency moving
into stage 2.
K complexes: large negative wave followed by large positive
wave
Sleep spindles: 1 to 2 second waxing/waning burst
, - Stage 3: DELTA waves largest and slowed EEG waves – largest voltage
low frequency
- Emergent state: Cycle goes back to stage 1
Recognizing sleep waves
, Characteristics of REM sleep
- Rapid Eye Movements (REM) occur under the eyelids in sleep
- Characteristics include REMs, loss of core-muscle tone, and a low-
amplitude, high-frequency EEG
- Cerebral firing increases, etc.
- 80% of awakenings from REM sleep led to dream recall (external
stimuli incorporated into dreams, run on real time, etc.)
Somnambulism and dreaming (which phase)
- Somniloquy: sleep talking
- Somnambulism: sleepwalking
- Sleep talking can occur at any phase of sleep
- Sleepwalking usually occurs during slow-wave sleep (stage 3), and it
NEVER occurs during REM sleep
Consequences of sleep deprivation
- Most people who are sleep deprived as so because of stress
- Prediction: Excessive wakefulness results in debilitating physiological
deficits, which will worsen with more sleep deprivation
- Results: no marked physiological disturbances, sleepiness, mood
disturbances, problems maintaining vigilance, micro sleeps, poor
executive function
Insomnia & Hypersomnia
- Insomnia: too little undisturbed sleep, can be iatrogenic, delayed falling
asleep, only 4 ½ hours of sleep, not staying asleep,
sleep restriction as a treatment
Causes include sleep apnea (either obstructive or central), periodic
limb movement syndrome, restless leg syndrome
- Hypersomnia: excessive/ inappropriate sleep
Narcolepsy
The orexin gene that promotes wakefulness is reduced
