Unit 3/Part 3: Physiological Measurements Of Consciousness Flashcards

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1
Q

List the four main brainwaves and their characteristics.

A

Beta - high frequency, low amplitude. Occurs during REM sleep (dreaming) as well as being awake and alert.
Alpha - high frequency but lower than beta, low frequency but higher than beta. Occurs when drowsy, daydreaming or during meditation.
Theta - medium frequency, mixed amplitude. Occurs during light sleep (NREM 1&2) *remember Thea likes M&M’s
Delta - low frequency, high amplitude. Occurs during deepest sleep (NREM 3&4)

REMEMBER B.A.T.D

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2
Q

List and explain the 3 other brainwave patterns.

A

K-complexes: sharp rise and fall of amplitude (high bursts of amplitude) lasting for about 2 seconds. Associated with stage 2 NREM sleep.
Sleep spindles: periodic bursts of rapid frequency, which are indicative of stage 2 NREM sleep.
Sawtooth waves: random fast waves that are slightly bigger than alpha waves. They resemble waves for being awake but occur among the beta-like waves during REM sleep. Medium to high amplitude. Sawtooth waves are associated with dreaming.

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3
Q

When we are lying in bed, feeling drowsy but still awake, we are likely to exhibit what type of brainwaves?

A

Alpha (high frequency but lower than beta and low amplitude but higher than beta)

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4
Q

Sawtooth brainwaves are associated with what stage of sleep?

A

REM sleep

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5
Q

How is the EOG useful?

A

It’s useful in measuring sleep because it determines which phase of sleep an individual is in judging by eye movement.

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6
Q

How is the Electromyograph useful?

A

Measuring changes in electrical activity in the muscles that accompany changes on states of consciousness. It can also be useful in determining whether a person is awake or asleep, and if asleep, which one of the two main types of sleep (REM or NREM).

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7
Q

What is a polysomnogram?

A

A continuously moving chart that displays data collected from the EEG, EOG, EMG and other devices. It’s useful in measuring sleep as it enables a researcher to compare corresponding data and make informed decisions about the state of consciousness a person is in and indicates REM or NREM stages.

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8
Q

Describe an ECG.

A

An electrocardiograph is a device that detects, amplifies and records electrical activity of the heart muscles. Heart rate is measured in beats per minute.

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9
Q

Name 2 states in which heart rate increases and 2 in which it decreases.

A

Increases: strong emotions, physical activity and stimulant drug e.g. Caffeine
Decreases: drowsiness and meditating

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10
Q

When is our body temperature lowest in a 24-hour period?

A

Body temperature tends to peak mid-afternoon and reach lowest point in early hours of the morning (1am-4am).

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11
Q

What happens to the GSR when we sweat?

A

Strong emotions and or physical activity during NWC increases GSR, whereas it decreases when relaxed and in cool environment. In some ASC, GSR will increase (alcohol induced state) and decrease (meditation). When sweat decreases electrical conductivity (current passes slower) and resistance increases and vice versa.

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12
Q

What sort of data is normally gathered in a sleep lab?

A

Video monitoring and self reports as well as data from physiological measurement devices.

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13
Q

Name one advantage and disadvantage of a sleep lab.

A

Advantage: allows brainwave activity and other physiological measures to be monitored in a controlled environment.
Disadvantage: participant may feel uncomfortable and face difficulty falling asleep due to unfamiliar environment as well as disrupted sleep.

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14
Q

Name one advantage and disadvantage of video monitoring.

A

Advantage: provide insight into how we behave in different states of consciousness. Researchers can observe participants at any time and give to other researchers to interpret.
Disadvantage: can’t tell us what’s going on inside the body or what the participant is experiencing. Therefore observations may be subjective.

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15
Q

What is a self report?

A

Statements and answers to questions made by the participants concerning their psychological experience (thoughts, feelings and behaviours). Carried out in number of ways such as questionnaires, diary entries and interviews.

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16
Q

Name an advantage and disadvantage of a self report.

A

Advantage: captures persons psychological experience and indicates whether or not person is in NWC or ASC.
Disadvantage: participants may forget info or may not know how to describe experience.

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17
Q

What percentage of our life do we spend in the ASC we call sleep?

A

33%

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18
Q

Why is sleep considered a circadian rhythm?

A

Because the sleep/wake cycle is an example of a biological rhythm that occurs approximately once every 24 hours.

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19
Q

What are the two different types of sleep?

A

NREM and REM

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20
Q

Explain NREM

A

NREM stands for non-rapid eye movement, which is divided into four states of sleep. Stages are determined by brainwave patterns.

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21
Q

Explain REM

A

Rapid eye movement stage of sleep, the amount of time spent in REM sleep increase and NREM decreases as the night progresses.

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22
Q

What is the NREM/REM cycle an example of?

A

An ultradian rhythm, a biological rhythm that’s shorter than 24 hours.

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23
Q

How long does REM/NREM cycle last?

A

90 minutes on average.

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24
Q

What brainwaves occur when we’re awake?

A

Beta waves; short (low amplitude) and fast (high frequency)

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25
Q

What percentage of time is spent in NREM sleep?

A

80%

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26
Q

Describe what happens in the twilight stage of sleep, known as the hypnagogic state.

A

During this state (transition from being awake to falling asleep) we may experience hallucinatory images, such as flashes of light and vivid images.

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27
Q

What are hypnic/hypnagogic jerks?

A

Involuntary muscle twitches that cause us to jolt.

28
Q

What is the length of time for stage 1 NREM sleep?

A

Can last between 30 seconds to 10 minutes, typically 5 minutes.

29
Q

What physiological changes occur during stage 1 NREM?

A

Irregular heart rate and breathing rate, relatively tense muscles and normal body temperature.

30
Q

Describe stage 1 EEG patterns.

A

Consists of theta brainwaves, which are mixed amplitude (some high some low) and medium frequency (not too fast but not too slow)

31
Q

What is the duration of stage 2 NREM sleep?

A

Approximately 20 minutes.

32
Q

Why is stage 2 NREM termed a ‘light’ stage of sleep?

A

Because it’s still easy to be woken up at this stage.

33
Q

Describe stage 2 NREM EEG patterns.

A

Brainwave
At terms consist of sleep spindles (short bursts of rapid brainwave activity) and K-complexes (single sudden high amplitude waves) among theta waves. K-complexes occur about once a minute in stage 2.

34
Q

What physiological changes occur during stage 2 NREM sleep?

A

Heart and breathing rate become slower and more regular. Muscle tension becomes lower as well as body temperature.

35
Q

What physiological changes occur during stage 3 NREM sleep?

A

Our sleep state changes to moderately deep sleep, our brainwaves change to delta and theta and heart and breathing rate continue to become slower and more regular. Our muscle tension and body temperature continues to decrease.

36
Q

Describe stage 3 NREM EEG patterns.

A

Slower (low frequency) and larger (high amplitude) delta waves become more common.

37
Q

What is slow wave sleep?

A

Sleep stages 3&4 NREM, because their main distinguishing features is the percentage of delta waves.

38
Q

How long does it take to first reach stage 4 NREM?

A

Roughly an hour and we spend approximately 30 minutes on stage 4 NREM.

39
Q

Describe the brainwaves associated with stage 4 sleep.

A

Brainwave patterns consist of regular, slow and large delta waves for more than 50% of the time.

40
Q

Describe the physiological changes that occur during stage 4 NREM sleep.

A

Deep sleep, delta brainwaves, slow and regular heart and breathing rate. Low muscle tension and body temperature at its lowest.

41
Q

In what stages of sleep is sleepwalking most likely to occur?

A

It can occur at any stage, although it’s more common in NREM.

42
Q

Describe the brainwaves associated with REM sleep.

A

Resemble those of a person that’s awake and alert, consist of beta-like and sawtooth waves.

43
Q

How does the body’s internal functioning during REM sleep compare with that of NREM sleep?

A

In stages of NREM sleep heart rate, breathing rate and body temperature decrease compared to REM when they increase and fluctuate.

44
Q

Why is REM sleep also known as ‘paradoxical sleep’?

A

Because the body can appear calm on the exterior (virtually no muscle activity) but other bodily systems and the brain are highly active, having feature similar to being awake.

45
Q

What are the characteristics of dreams in REM sleep?

A

Tend to follow a story line (can be bizarre) and dreamer often feels as if they’re experiencing a different world. Final dream of the night tends to be the longest, strangest and most exciting - elements that make it more likely to be remembered.

46
Q

How are dreams in NREM sleep different to dreams in REM sleep?

A

Less frequent, more difficult to remember, tend to be similar to waking thought patterns, less intense and without a storyline.

47
Q

What happens to the amount of time spent in REM sleep as the night progresses?

A

We spend a larger amount of time in REM sleep.

48
Q

How long on average do infants sleep? Adults sleep? Older adults?

A

Infants (newborns) spend on average 16 hours a day sleeping, adults spend 8 and older adults spend 6 hours per day.

49
Q

What happens to the percentage of time spent in REM sleep as we age?

A

As we age the percentage of time spent in REM decreases.

50
Q

Name the 2 main sleep theories.

A
  • survival (adaptive and evolutionary) theory

- restorative (restore and recovery) theory

51
Q

According to the survival theory, what’s the purpose of sleep?

A

It’s purpose is increasing an animals chance of survival.

52
Q

How is sleep adaptive?

A

It allows us to change to meet the demands of our environment and it depends on how much food we need, how available it is (we may need to conserve energy) and our safety when we sleep.

53
Q

Outline the 3 main points of the survival theory.

A
  • sleep depends on the need to find food: animals that need to graze for hours, such as cows, sleep less. They sleep less because they need more food to survive.
  • sleep depends on an animals vulnerability to predators: small animals that are very vulnerable to predators, such as mice, sleep more so they can hide safely from carnivores that will eat them. The larger the animal and the more they’re exposed in their environment, the less they sleep.
  • sleep conserves energy: when an animal sleeps, it’s metabolism slows, thus reducing the need for food. A humans metabolic rate during sleep is about 10% less than when awake. Animals such as squirrels and bears sleep during winter months when food is scarce and the weather conditions are harsh.
54
Q

What are the two main criticisms of the survival theory?

A
  • the assumption that sleep is useful but not essential. Survival theory doesn’t explain why we must have sleep.
  • the assumption that sleeping is a way to hide safely from predators. For animals that are highly preyed upon, sleeping can be dangerous.
55
Q

According to the restorative theory, what’s the purpose of sleep?

A

It allows us to recharge our bodies, recover from the physical and physiological work during the day and allows our bodies growth processes to function.

56
Q

What evidence is there for sleep repairing and replenishing the body?

A
  • neurotransmitter adenosine acts as a cellular waste in the brain that increases when we’re awake and causes us to feel tired. Sleep fundamentally decreases levels of adenosine, thus making us feel more refreshed and awake.
  • number of hormones are also activated when we sleep, so not getting enough sleep can lead to negative thoughts, feelings and behaviours.
  • activates growth hormone: the more you sleep, the more likely you’re going to grow and meet your potential growth. Growth hormone is also involved in controlling metabolism.
  • increases immunity to disease: immune cells that fight disease and infections are produced during sleep, therefore they can repair the body during sleep.
57
Q

What sleep stage is most important for repairing and replenishing the body?

A

Stages 3&4 of NREM

58
Q

What role does sleep play in learning and remembering new info?

A

Sleep assists with the consolidation of memories, a process whereby new memories are transferred into long-term memory.

59
Q

What are 2 main criticisms of the restorative theory?

A
  • the assumption that more sleep is needed to recover when we’re physically active. Unless we partake in extreme physical activities, there’s little evidence that we need more sleep when we exercise.
  • the assumption that the body rests during sleep: the brain is active during sleep. Increased blood flow and energy expenditure occurs during REM sleep and this slows down the synthesis of proteins, assisting the body in getting ready for the next day.
60
Q

What stages of sleep are night terrors more likely to occur in?

A

Stages 3&4 of NREM

61
Q

When are nightmares more likely to occur?

A

REM sleep

62
Q

What explanation is provided for the change of time spent in REM sleep?

A

It’s believed children spend more time in REM as its critical for brain development (forming new memories and neural pathways)

63
Q

Outline 3 ways to distinguish between nightmares and night terrors.

A
  • Nightmares usually occur in REM sleep, whereas night terrors occur during stages 3&4 of NREM sleep.
  • There are little physiological changes in nightmares, whereas a person may experience rapid breathing and heart rate when having a night terror.
  • When an individual is experiencing a nightmare they I’ll have very little movement, compared to when experiencing a night terror. They will experience violent body movements such as sitting up, crying and possibly running.
  • People will often awaken during or immediately after a nightmare, whereas when experiencing a night terror they will wake but usually fall asleep quickly again.
  • Nightmares are usually remembered, whereas night terrors generally cannot be remembered.
64
Q

Body temperature can be used to study sleep because it?

A

follows a regular daily cycle

65
Q

If Megan’s alarm had rung after she had been asleep for only a couple of hours, it is likely that?

A

It would be difficult to wake her as she is likely to be in NREM stages 3&4.

66
Q

Describe 2 sleep-wake shifts that could be observed in the sleep patterns of a healthy adolescent compared with those of an adult.

A
  • delayed onset of sleep I.e. Typically 2 hours later than adults.
  • delayed waking in the morning.
67
Q

In an EEG recording, deep sleep is indicated by?

A

Theta and delta waves