PSY 3128 Lecture 5: Sleep and Ageing
5 Jun 2018
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Lecture 5: Sleep and Aging
Guest Lecturer Stuart Fogel
Sleep and Aging: has implcaitions for cognition, something that everyone does probably about 1/3 of their life, and is
something that people notice changing as they get older.
We don’t completely know why we sleep:
- It is a relatively young field of study
- What functions does it afford to us?
- We are trying to understand it based on its physiology
Scalp recorded EEG picks up on subtle electrical activity.
Alpha: slow rhythmic waves that appear in relaxed wakefullness.
Smaller, quicker waves when we are awake and active.
Stage 1 Sleep
- Theta waves start to appear in stage 1 sleep, the transition stage.
- Sleep onset period or process.
- Characterized by Theta waves, sharp waves, which happen in busrts. Mixed activity in stage one, some
slowing of the EEG, highly variable in the types of activity.
Stage 2: you start to start to see sleep spindles and a k-complex, large k-complexes begin to appear.
- Sleep spindles which last from .25-2 seconds
- Hertz refers to cycles per second and are increasingly lower as you get into deeper sleep
- When you enter stage 2 sleep you begin to see sleep spindles and k-complexes
- K-complexes are studied by Kenneth Cambell does a lot of research, you trigger a x-complex when you
hear your name while you are in stage 2 sleep
- Used to be called filler or non-resorative sleep
Stage 3: Large delta waves, found to be important for growth as it is the only time that follicale stimulating hormone
or other growth hormones are secreted in this stage.
- 0-4 hertz (ie waves per second)
- found more in adolescents thatn older adults
REM: look like awake and active waves.
- Most prominent for dreams, but it is well understood now that dreams occur in all stages of sleep, dream-
like event even occur in stage one
- REM is paradoxical sleep because the EEG looks like waking, desunchronized, low amplitide waves
Sleep Cycles
- Illustrated by a hypnogram
- Altradian cycles, every 90 minuets in a normal adult
- Even individuals with narcolepsy have 90 minuet cycles that run throughout the entire day
How is sleep measured? Electroencephalography (EEG)
- Placed on the head proprotionaltly throughout the 10-20 system
- Spindles are found centrally on the recording
Polysomnography (PSG)
- Not just electrodes on the scalp and eyes
- Used to measure all clincial indicators of sleep
- Sensor on your finger for pulse oximintry
- Used more in sleep clinics than in research
- Respirator measurement for sleep apnea indicators
The Ontology of Sleep
Newborn Sleep
- REM is an important process for plasticity, as indicated by newborns getting a ton of REM sleep
- We do not use the same categories as the system
- Quite sleep is more like SWS and active sleep is more like REM
- Rat sleep is like newborn sleep
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Sleep and aging: has implcaitions for cognition, something that everyone does probably about 1/3 of their life, and is something that people notice changing as they get older. It is a relatively young field of study. We are trying to understand it based on its physiology. Scalp recorded eeg picks up on subtle electrical activity. Alpha: slow rhythmic waves that appear in relaxed wakefullness. Smaller, quicker waves when we are awake and active. Theta waves start to appear in stage 1 sleep, the transition stage. Characterized by theta waves, sharp waves, which happen in busrts. Mixed activity in stage one, some slowing of the eeg, highly variable in the types of activity. Stage 2: you start to start to see sleep spindles and a k-complex, large k-complexes begin to appear. Hertz refers to cycles per second and are increasingly lower as you get into deeper sleep. When you enter stage 2 sleep you begin to see sleep spindles and k-complexes.
