9. Sleep & Circadian Rhythms

Question 1

Sleep is a n____, p____ state that involves r____ r____ to e____ s____ and decreased m____

Answer 1

natural, periodic, reduced responses, environmental stimuli, mobility

Question 2

Sleep is a behaviour observed in h____ across c____, and other s____, even in u____ organisms. We spend a t____ of our lives asleep

Answer 2

humans, cultures, species, unicellular, third

Question 3

Sleep is controlled mainly by two processes:
1. H____ (S) - if we do not sleep, we a____ sleep d____
2. C____ (C) - sleep tends to happen at a p____ t____ during the 24-hour cycle

Answer 3

1. homeostatic, accumulate, debt
2. circadian, particular time

Question 4

P____ is the ‘gold standard’ of sleep research discovered by Hans Berger (1929).
It was initially used in c____ but now is used for research and clinical purposes in h____ and other s____.
It involves recordings of e____ activity from m____ sources.
Recordings revealed a specific s____ a____

Answer 4

Polysomnography
cats, humans, species
electrical, multiple
sleep architecture

Question 5

Polysomnography involves:
1. E____ recordings (e____) = recordings of activity of populations of n____ in the b____ underneath the s____
2. E____ recordings (e____) = recordings of activity of the m____ around the e____ to decipher e____ m____
3. E____ (e____) = recordings of the activity of the m____ in the b____
These recordings can be combined with others such as h____ r____, t____, b____ (O2) etc.

Answer 5

1. EEG, electroencephalogram, neurons, brain, skull
2. EOG, electrooculogram, muscles, eyes, eye movements
3. EMG, electromyogram, muscles, body
   heart rate, temperature, breathing

Question 6

During wakefulness, different types of neuronal activity are observed in the EEG recording:
1. B____ waves consisting of i____ activity of 13-30Hz
–> B____ activity takes place when the brain is p____ i____
–> the person is a____ and a____ to events in the e____ or e____ in cognitive processes
2. A____ waves consist of activity of 8-12Hz
–> occur when a person is r____ q____, not particularly a____ or e____ and not engaged in s____ m____ activity

Answer 6

1. beta, irregular, beta, processing information, alert, attentive, environment, engaging
2. alpha, resting quietly, aroused, excited, strenuous mental

Question 7

Sleep begins with a state of r____, feeling d____

Answer 7

relaxed, drowsy

Question 8

Stage 1 = presence of t____ activity - a t____ between sleep and wakefulness

Answer 8

theta, transition

Question 9

Stage 2 = characterised by i____ activity and also s____ s____, although these occur in other stages of sleep, and __ c____ which are only found during stage 2

Answer 9

irregular, sleep spindles, K complexes

Question 10

Stage 3 = high-a____ and low-f____ d____ activity. S____, r____ waves reflecting s____ and c____ in the activity of neurons in underlying brain areas. There is a slowing down of brain activity as well as other b____ functions, such as heart rate, breathing, temperature and kidney function. Sometimes referred to as s____-w____ sleep (SWS) or d____ sleep

Answer 10

amplitude, frequency delta
synchronised, regular, synchrony, coordination
bodily
slow-wave, deep

Question 11

REM sleep = a sleep phase characterised by increased brain activity and a____ in brain waves accompanied by m____ a____.
Aserinsky and Sleitman (1953): sleep characterised by r____ e____ m____ (REM sleep)
Michel Juvet (1959): deep sleep, in terms of m____ activity but light sleep in terms of b____ activity - p____ sleep
F____ t____, e____, v____ s____ and d____ occur during this stage

Answer 11

asynchrony, muscle atonia
rapid eye movement
muscle, brain, paradoxical
facial twitches, erections, vaginal secretions, dreaming

Question 12

Sleep recordings revealed f____ distinct patterns of activity, t____ stages of sleep (NREM) and an additional REM sleep episode. We c____ through each stage and back, with each c____ lasting approximately __ minutes

Answer 12

four, three, cycle, cycle, 90

Question 13

Dement and Kleitman (1957) discovered that when pts were awakened from REM sleep, they tended to report v____ d____

Answer 13

vivid dreams

Question 14

Dreams are considered important in p____ and accessing the u____

Answer 14

psychoanalysis, unconscious

Question 15

Most dreams are r____ to e____ that happen in a person’s l____

Answer 15

related, events, life

Question 16

Calvin Hall et al (1982): analyzed 10,000 dreams of healthy people and found that more than __4% are associated with sadness, anxiety or anger whereas __8% are happy dreams and only __% involved sexual content

Answer 16

64, 18, 1

Question 17

The Activation Synthesis Hypothesis of Dreams:
1. J. Allan Hobson (2004) proposed that there is no m____ in dreaming, even though dreams are based on each person’s e____
2. The b____ is activated during REM and sends signals to the cortex (v____ a____ cortex) which creates i____ with a____ and e____
3. The f____ cortex is less activated during dreaming so there is no l____ in the t____ or the s____ of events
4. The person tries to o____ the content into a l____ s____ when awake, so it is a b____-u____ view on dreams

Answer 17

1. meaning, experiences
2. brainstem, visual association, images, actions, emotions
3. frontal, logic, timing, sequence
4. organise, logical story, bottom-up

Question 18

Many n____ substances cause sleep (i.e. m____)

Answer 18

natural, morphine

Question 19

N____ and h____ can produce sleep-wake cycles

Answer 19

neurochemicals, hormones

Question 20

Adenosine a____ during the day, after p____ wakefulness and p____ sleep. C____ antagonises the effects of adenosine and decreases s____

Answer 20

accumulates, prolonged, promotes
caffeine, sleepiness

Question 21

Constantine von Economo early 20th century observed patients with encephalitis:
1. Most had c____ s____ and would wake up only to e____ and d____. They had damage in the b____ of the brain
2. Fewer patients displayed i____, these had damage in the a____ h____
3. This area of the a____ h____ was later identified as the v____-l____ p____ area (vlPOA) which contains i____ n____ such as G____

Answer 21

1. continuous sleepiness, eat, drink, base
2. insomnia, anterior hypothalamus
3. anterior hypothalamus, ventro-lateral preoptic, inhibitory neurotransmitters, GABA

Question 22

Moruzzi and Mogoun (1949) discovered brain regions involved in wakefulness and arousal accidentally:
1. While recording from a____ c____, they stimulated the c____ b____ and noticed that the d____ waves were replaced by b____ waves
2. So, stimulating the b____ in a sleeping c____ resulted in w____ the animal

Answer 22

1. anaesthetised cats, cat’s brainstem, delta, beta
2. brainstem, cat, waking

Question 23

The r____ f____ is responsible for wakefulness. It is comprised by a group of n____ in the b____ that send p____ to the f____ to promote a____

Answer 23

reticular formation (Reticular Activating System-RAS)
nuclei, brainstem, projections, forebrain, arousal

Question 24

Orexin or hypocretin is a p____ released from the l____ h____ that is highly responsible for the m____ of w____. It is implicated in n____

Answer 24

peptide, lateral hypothalamus, maintenance, wakefulness, narcolepsy

Question 25

Sleep deprivation in rats: 1. The animals looked s____, they stopped g____, became w____ and lost their ability to t____ 2. they were losing w____ although they were e____ more and eventually they d____

Answer 25

1. sick, grooming, weak, thermoregulate 2. weight, eating, died

Question 26

Sleep is a____... the original function of sleep was probably to c____ e____. Normally our brain spends ~__% of our energy even thought it is very small (__%) compared to our body weight. This is true especially for NREM sleep, particularly SWS where m____ r____ and b____ f____ to the brain decrease, but not for REM sleep

Answer 26

adaptive, conserve energy 20%, 2% metabolic rate, blood flow

Question 27

Conserving energy whilst asleep: 1. Decrease in body t____ of about __-__ degree celsius in mammals 2. Decrease in m____ activity 3. Increase in sleep time when there is s____ of f____

Answer 27

1. temperature, 1-2 2. muscle 3. scarcity, food

Question 28

Sleep is r____... sleep takes place at n____, at the end of a b____ day and helps us to feel r____ and e____ the next day. Activity during wakefulness results in the a____ of free r____ (oxidative stress) and potentially t____ waste (such as a____ b____). During sleep, r____ mechanisms take place to remove free r____ and t____ waste.

Answer 28

restorative, night, busy, refreshed, energised accumulation, radicals, toxic, amyloid beta, restorative, radicals, toxic

Question 29

Sleep promotes d____... i____ sleep a lot more than a____. REM sleep in adults accounts for about __-__% of total sleep whereas in infants it takes up to __% of total sleep time. During stage 3 sleep (SWS), g____ h____ (GH) release is at its p____ which is important for g____

Answer 29

development, infants, adults, 20-25%, 50% growth hormone, peak, growth

Question 30

Sleep facilitates c____... 1. Sleep enhances l____ and m____ --> Performance on a newly learned task is often better the next day if a____ sleep is achieved during the night whereas d____ are evident following sleep-d____ --> During sleep, neurons r____ the previous experience to r____ the information (Wilson and McNaughton, 1994). --> Evidence that possibly different t____ of learning may be supported by the different s____ of sleep (SWS vs REM and declarative vs non-declarative) 2. P____-s____ and c____ --> During sleep, the brain continues to p____ material and enables the s____ to problems, as evidenced by the “a____” phenomenon upon waking

Answer 30

cognition 1. learning, memory --> adequate, deficits, deprivation --> replay, retain --> types, stages 2. Problem-solving, creativity -->process, solution, aha

Question 31

Circadian rhythms are rhythms or r____ p____ of activity associated with a 24hr-cycle such as d____ and n____. Humans are d____ (vs n____)

Answer 31

regular patterns, day, night, diurnal, nocturnal

Question 32

Endogenous cycles are generated from w____. Our brain and body s____ generate their own r____ based on the earth'e r____. Endogenous rhythms can also be a____ (migration) or s____ (breeding)

Answer 32

within, spontaneously, rhythms, rotation annual, seasonal

Question 33

Our 24hr circadian rhythm not only controls s____ and w____ but also other important functions such as b____ t____, s____ of h____, u____ etc

Answer 33

sleep, wakefulness, body temperature, secretion, hormones, urination

Question 34

B____ are not unique to humans and animals. Flowers may o____ during the day and c____ during the night. 1729: French geologist, Jean Jacque d’Ortous de Mairan experimented with the mimosa plant and found that even if isolated from l____, d____ or t____ cues the leaves continued their r____ behaviour.

Answer 34

Biorhythms, open, close, light, dark, temperature, rhythmic

Question 35

Aschoff (1965): 1. Humans placed in an u____ b____ where there were no e____ c____ 2. The pts continued to show daily sleep-activity rhythms, even though they drifted to >__hrs 3. Concluded that humans have an e____ b____ c____ which governs sleep-wake behaviour

Answer 35

1. underground bunker, external cues 2. 24 3. endogenous biological clock

Question 36

External cues that serve to set our biological clock are called Z____ ("t____ g____"). The most potent z____ for humans is l____, although there are others. When a z____ resets a biorhythm, that rhythm is said to be e____.

Answer 36

Zeitgebers, time givers, Zeitgeber, light, Zeitgeber, entrained

Question 37

Jet lag is d____ of the circadian rhythms due to crossing t____ z____. It stems from a m____ of the i____ circadian clock and e____ time. It involves s____ during the day, s____ at night and impaired c____. Traveling west "p____-d____" our circadian rhythms whereas trailing east "p____-a____" our circadian rhythms

Answer 37

disruption, time zones, mismatch, internal, external, sleepiness, sleeplessness, concentration phase-delays, phase-advances

Question 38

Circadian rhythms may differ between people and can lead to different patterns of wakefulness and alertness. This is called c____. Morning people are sometimes referred to as "l____" and evening people as "o____". Rhythms have a g____ basis, but they also change as a function of a____ and other external factors.

Answer 38

chronotypes larks, owls genetic, age

Question 39

We all start off (infancy and childhood) and finish off (adulthood and old age) as m____ people ("l____"). During adolescence there is an increasing shift towards “e____” – teenagers become “o____”, which is particularly difficult given that s____ starts early in the morning. Differences in chronotype may result in "s____ j____ l____". Morning people report to be h____ than evening people.

Answer 39

morning, larks eveningness, owls, school social jet lag happier

Question 40

Curt Paul Richter, Prof. of Psychobiology at Johns Hopkins (1927): Introduced the concept that the brain generates its own rhythms, so it must have a b____ c____ which he attempted to locate in the brains of wild rats. He performed e____ l____ in various parts of their brain in order to l____ the b____ c____. The rats lost their r____ behaviour after damage o the h____.

Answer 40

biological clock, electrical lesions, biological clock, rhythmic, hypothalamus

Question 41

The primary biological clock is located in the s____ n____ (SCN) of the h____. Lesions of this n____ disrupted circadian rhythms of w____ r____, d____, h____ s____ and was thus named "the m____ clock".

Answer 41

suprachiasmatic nucleus, hypothalamus nucleus, wheel running, drinking, hormonal secretion, master

Question 42

Recording electrodes in the SCN confirm that n____ are more active during the l____ period than during the d____ period. A single cell extracted from the SCN and raised in t____ c____ continues to function in a r____ pattern. T____ of an SCN into a d____ organism results in the r____ following the d____ rhythm!

Answer 42

neurons, light, dark tissue culture, rhythmic transplantation, donor, recipient, donor

Question 43

The SCN receives information about light through the r____ t____, formed by a special population of g____ c____ (p____ r____ g____ c____ - PRGCs) which make up ~1-3% of g____ cells. These PRGCs have their own p____ called m____ and can respond directly to light, especially b____ light. They don't rely on r____ and c____ which explains the fact b____ people remain entrained. Experiments where r____ and c____ were i____ had no effect on circadian rhythms. Part of this tract terminates in the m____ to control the size of the p____ in response to light.

Answer 43

retinohypothalamic trac, ganglion cells, photosensitive retinal ganglion cells, ganglion photopigment, melanopsin, blue rods, cones, blind rods, cones, inactivated midbrain, pupil

Question 44

The SCN drives a number of s____ o____, each responsible for the t____ of a different type of behaviour i.e. digestion, body temperature, activity etc

Answer 44

slave oscillators, timing

Question 45

The SCN regulates behaviour including w____ and s____ by controlling activity levels in other brain area and s____ g____ such as the p____ g____ and the p____ g____.

Answer 45

waking, sleeping, secretory glands, pituitary gland, pineal gland Pituitary - glucocorticoid release, light phase, arousal activities Pineal - melatonin release, dark phase, rest activities

Question 46

Dreams may help us find solutions to o____ p____

Answer 46

ongoing problems

Question 47

B____ of animals is controlled by the SCN via the pineal gland. During w____, the increased m____ produced at night inhibits the gonads (testes) which s____ During s____, there is less m____ which allows the gonads to e____, to produce t____ and support m____ behaviours

Answer 47

breeding winter, melatonin, shrink spring, melatonin, enlarge, testosterone, mating

Question 48

The time of day affects p____ in humans on a wide range of cognitive tasks measuring a____, e____ functions and m____

Answer 48

performance, attention, executive, memory

Question 49

Adenosine is produced by a____

Answer 49

astrocytes

Question 50

T____ of disease can be influenced by circadian rhythms i.e. surgery outcome or pharmacotherapy: 1. T____ of a drug varies from __-__% depending on the time of day 2. R____ for i____ also changes depending on the time of day, i.e. there is a higher likelihood of a stroke or heart attack in the morning

Answer 50

Treatment 1. Toxicity, 20-80 2. risk illness