Chapter 9 - Sleep Flashcards
daily rhythmical change in behaviour or psychological process
circadian rhythms
stimulus that resets the biological clock responsible for circadian rhythms
zeitgebers
SCN
central to biological clocks
- a hypothalamc nucleus containing the biological clock for many of the body’s circadian rhythms
- lesions disrupt circardian rhymths of wheel runing etc.
- provides primary control over the timing of sleep cycles.
retinohypothalamic pathway
direct projection from retina to SCN
photochemical
melanopsin (ganglion cells)
how does SCN control sleep/wake cycle
SPZ - DMHz - vlPOA & orexin in LH
projections to vlPOA are
inhibitory - inhibit sleep
projections to orexin neurons in LH are
excititory - promote wakefulness
measure neural events
EEG
measure eye movements
EOG
measure muscle tension
EMG
large disk electrode places on scale record electrical potentials
- extracellular voltage changes over large area of cortex
EEG
stages of sleep
alert - low amplitude, high freq. beta waves
drowsy - similar to alert but, occasional alpha waves
stage 1 - similar to alert but, slower and higer amplutide (theta waves)
stage 2 - similar to stage 1 bur, ossasional sleep spindles and K-complexes
stage 3 - slower, larger, occasional delta spikes
stage 4 - predominance of delta spikes
low amplitude, high frequency. beta waves
alert
low amplitude (slightly higher), occasional alpha waves
drowsy
slower and higher amplitude. theta waves
- light sleep, muscle activity slows down, occasional muscle twitching
stage 1
occasional splindles and k-complexes. (large negative followed by large positive deflection)
- breathing pattern and heart rate slows. slight decrease in body temperature.
stage 2
slower, larger , occasional delta spikes
- deep sleep begins. brain begins to generate slow delta waves
stage 3
predominance of delta spikes
- very deep sleep. rhymthic breathing. limited muscle activity. brain produces delta waves.
stage 4
loss core muscle tone
low amplitude, high frequency EEG
cerebral activity (O2 consumption, blood flow, neural firing) increases to waking levels
general increase in NS (bp, pulse)
when awaken, person appears alert and attentive
- penile erection/vaginal secretion
- dreams
- EEG desynchrony (rapid, irregular waves)
REM
EEG synchrony (slow waves)
moderate muscle tone
slow or absent eye movement
lack of genital activity
SWS
dreams during non-rem sleep
isolated experiences (ie: free falling)
dreams during rem sleep
stories
disguised versions of our real dreams
information that the conscious individual remembers experiencing. It consists of all the elements of actual images, thoughts, and content within the dream that the individual is cognitively aware of upon awakening.
manifest dreams
illustrates the hidden meaning of one’s unconscious thoughts, drives, and desires
latent dreams
information supplied to the cortex during REM sleep is largely random and that the resulting dream is the cortex’s effort to make sense of these random signals
activation-synthesis theory
REM
high blood flow to visual association cortex
low in primary visual cortex and PFC
- low activity in primary visual cortex - no input to eyes
- high level in visual association cortex - visual hallucinations that occur during day dreaming
- low in PFC - dreams are poorly organized with respect to time and other PFC tasks
nightmares
SWS - stage 4.
sleep restriction therapy
- the amount of time that an insomnia is allowed to spend in bed is reduced
- after a period of sleep restriction, the amount of time spend in bed is gradually increased in small increments
medical causes of insomnia
sleep apnea
periodic limb movement disorder
restless leg syndrome
fall asleep and then cease to breath
- CO2 in blood stimulates chemoreceptors, and person wakes up, grasping for air, O2 levels return to normal, person goes back to sleep, cycle begins again
sleep apnea