MAASTRICHT UNIVERSITY
PSY 3349
Sleep and Sleep Disorders
Elective course
Year 2018-2019
Table of contents:
Task 1 – quality and quantity .................................................................................................................. 1
Task 2 – sleep problems? ...................................................................................................................... 14
Task 3 – Wake problems?...................................................................................................................... 34
Task 4 – behavioural problems ............................................................................................................. 54
Task 5 – Daytime saving time ................................................................................................................ 70
Task 6 – sleep on it ................................................................................................................................ 88
, Sleep and Sleep Disorders
PSY3349
Task 1 – quality and quantity
1. What is a normal sleep cycle (stages etc.)?
2. How does age affect sleep cycles?
3. What is good sleep?
4. How can you measure sleep?
5. What is the Two Process Mode of Sleep Regulation and how does it work?
6. Sleep wake switch → what is it, how does it work, neural mechanisms
7. What is the effect of caffeine on sleep?
Sleep stages________________________________________________________________________
Carlson (2017) Physiology of behaviour (12th global edition); chapter 9
Researchers and physicians have examined the EEG record of sleepers and identified particular
patterns of waveform activity that correspond with different stages of sleep:
◼ Stage of wakefulness → Stage W
o Alpha activity - regular, medium-frequency waves of 8–12 Hz (hertz; measures cycles
per sec) → larger and slower brain waves
▪ When a person is resting quietly, not particularly aroused or excited and not
engaged in strenuous mental activity (such as problem solving).
▪ Mostly present when eyes are closed.
o Beta activity - irregular, mostly low-amplitude waves of 13–30 Hz. → low amplitude
and high frequency.
▪ Beta activity shows desynchrony; it reflects the fact that many different
neural circuits in the brain are actively processing information.
▪ Desynchronized activity occurs when a person is alert and attentive to events
in the environment or is thinking actively.
◼ 3 stages of non-REM sleep → NREM 1, 2 and 3
o When falling asleep you enter stage 1 sleep, marked by the presence of theta
activity (3.5-7.5 Hz), which indicates that the firing of neurons in the neocortex is
becoming more synchronized.
▪ This stage is actually a transition between sleep and wakefulness;
▪ Eyes could open and close and eyes roll upward and downward.
▪ Sleeper may experience hypnic jerks; muscle contractions followed by
relaxation(experienced falling sensation).
o +/- 10 min later you enter stage 2 sleep, which contains periods of theta activity with
sleep spindles and K complexes.
▪ Sleep spindles are short bursts of waves of 12–14 Hz that occur between two
and five times a minute during stages 1–3 of sleep.
• Appear to play a role in consolidation of memories
▪ K complexes are sudden, sharp waveforms, which, are usually found only
during stage 2 sleep. They spontaneously occur at the rate of approximately
one per min but often can be triggered by (unexpected) noises.
▪ The person is sleeping soundly now; but if awakened, she might report that
she has not been asleep.
o +/- 15 min later you enter slow-wave sleep, signaled by the occurrence of high-
amplitude delta activity (less than 3.5 Hz) in stage 3 sleep.
▪ the deepest stage of sleep; only loud noises will cause a person to awaken →
when awakened, the person acts groggy and confused.
▪ Biphasic waves: wave first goes down (resting phase of neuron) and secondly
goes up.
◼ One REM sleep stage→ stage R
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, Sleep and Sleep Disorders
PSY3349
o Changes in physiological measures: EEG becomes mostly desynchronized, with
occasional occurrences of theta waves; EOG records that the eyes are rapidly
moving; EMG becomes silent, there is a loss of muscle tone.
▪ Theta waves →low amplitude, high frequency waves.
o A person might not react to most noises, but he/she is easily aroused by meaningful
stimuli (sound of name). When awakened, a person appears alert and attentive.
o Cerebral activity (oxygen consumption, blood flow, and neural firing) increases to
waking levels in many brain structures & there is a general increase in the variability
of autonomic nervous system activity (in blood pressure, pulse, and respiration).
o Dreaming occurs.
Pinel: 3 sleep stages → stage 1, 2 and
3 EEG sleep. The first period of stage
1 EEG during a night’s sleep (initial
stage 1 EEG) is not marked by any
striking electromyographic or
electrooculographic changes,
whereas subsequent periods of stage
1 sleep EEG (emergent stage 1 EEG)
are accompanied by REMs and by a
loss of tone in the muscles of the
body core.
➔ REM sleep is thus the same
as stage 1 NREM sleep in the
second cycle.
Figure 9.3 shows a graph of a typical
night’s sleep. Each cycle is approximately 90 minutes long,
containing a 20- to 30-minute bout of REM sleep. After the first
cycle of sleep EEG—from initial stage 1 to stage 3 and back to
emergent stage 1—the rest of the night is spent going back
and forth through the stages.
◼ Note that most slow-wave sleep occurs during the first half
of night.
◼ While subsequent bouts (rondes) of non-REM sleep contain
more and more stage 2 sleep, and bouts of REM sleep become
more prolonged.
Physiological mechanisms of sleep and
waking___________________________________________
Carlson (2014) Ch 9 Sleep and biological rhythms [pp.312-319] In Physiology of Behaviour (11th Ed).
Neural control of sleep
Adenosine, a nucleoside neuromodulator, might play a primary role in the control of sleep:
◼ Astrocytes maintain a small stock of nutrients in the form of glycogen.
◼ In times of increased brain activity this glycogen is converted into fuel for neurons; thus,
prolonged wakefulness causes a decrease in the level of glycogen in the brain.
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, Sleep and Sleep Disorders
PSY3349
◼ A fall in the level of glycogen causes an increase in the level of extracellular adenosine,
which has an inhibitory effect on neural activity → This accumulation of adenosine serves as
a sleep-promoting substance.
◼ During slow-wave sleep, neurons in the brain rest, and the astrocytes renew their stock of
glycogen. If wakefulness is prolonged, even more adenosine accumulates, which inhibits
neural activity and produces the cognitive and emotional effects that are seen during sleep
deprivation.
o caffeine blocks adenosine receptors to reduce sleepiness
Neural control of arousal
At least 5 different NTs play a role in an animal’s level of alertness and
wakefulness → arousal.
◼ Acetylcholine (ACh) - Two groups of acetylcholinergic neurons (located
in pons and basal forebrain) produce activation and cortical
desynchrony when they are stimulated. A third group, located in the
medial septum, controls the activity of the hippocampus (fig 9.11).
o acetylcholinergic agonists increase EEG signs of cortical arousal
and acetylcholinergic antagonists decrease them.
o Levels of Ach in hippocampus and neocortex are high during
waking and REM sleep (periods of desynchronized activity) and
low during slow- wave sleep.
◼ Norepinephrine - Catecholamine agonists produce arousal and
sleeplessness; this is mediated by the noradrenergic system of the
locus coeruleus (LC) located in the dorsal pons. Neurons of the LC
give rise to axons that branch widely, releasing norepinephrine
throughout neocortex, hippocampus, thalamus, cerebellar cortex,
pons and medulla.
o The activity of these neurons is related to behavioural
arousal: firing rate is high during wakefulness, low during
slow-wave sleep, and almost zero during REM sleep.
o Activity of noradrenergic LC neurons increases an animal’s
vigilance—its ability to pay attention to stimuli in the
environment.
◼ Serotonin – plays a role in activating behaviour. Most of the
serotonergic neurons are found in the raphe nuclei, located in the medullary and pontine
regions of the reticular formation. Their axons project to many parts of the brain like the
thalamus, hypothalamus, basal ganglia, hippocampus and neocortex.
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