Week 11-12 (Consciousness) Flashcards

Question 1

Q

What is consciousness in research? (2)

Answer

A

In psychology/cognitive science, the term “Consciousness” is used interchangeably with “Awareness.”

Visual awareness, self consciousness (etc) are terms to refer to different forms or “contents” of consciousness

Question 2

Q

What is the easy problem vs the hard problem?

Answer

A

The easy problem

The difference between total unconsciousness vs anything more than that? (Unconsciouness vs Anything Else)

The hard problem

The quality of the experience colours, sounds, feelings (Why is the experience of colour different from sound)

- We are trying to solve the easy problem

Question 3

Q

What are experimental methods for consciousness research?

Answer

A

1.Binocular Rivalry

2. Backward Masking

Using stimuli that generate switches in perception without changes to the stimuli (like binocular rivalry or masking) with brain imaging or neural recordings can help identify activity associated with a conscious experience.

Question 4

Q

What is binocular rivarly as a experimental method for consciousness?

Answer

A

When two different images are simultaneously presented to the two eyes [constant stimuli], you will only be conscious of one of the two images at a time [fluctuating awareness].

Question 5

Q

What is backward masking as a experimental method for consciousness?

Answer

A

Manipulating time gap between mask (clap) and target (xxx)

The greater the delay between target and mask the more likely it will “make it through” to conscious access.

Question 6

Q

What is NCC (2). What are its limitations? (2)

Answer

A

Neural Correlates of Consciousness (NCC)

<ul> <li>Minimal set of neuronal events that give rise to a conscious percept (easy problem)</li> <li>At any point, some neurons correlate with consciousness and some does not. What is the difference?</li></ul>

Limitations

<ul> <li>NCC is not a complete explanation of consciousness.</li> <li>Might be a mystery now but the mystery will disappear when the biology is understood (like with DNA).</li></ul>

Question 7

Q

What is 1st theory: Sparse Coding Model?

Answer

A

“Sparse Coding”

<ul> <li>Relatively small collection of individual neurons (a few thousand) will be selective for a specific “concept” (identity, object or idea etc)</li></ul>

Question 8

Q

Example of Sparse Coding Model (3)

Answer

A

Grandmother/Jennifer Anniston Neuron

<ul> <li>Conscious experience of grandmother requires neurons in your brain coding “grandmother” to fire.</li> <li>Activity of this cell ensemble is invariant (insensitive) to orientation, size, location etc and would fire every time you saw or imagined (heard or smelt) your grandmother.</li> <li>Using binocular rivalry, they also found neurons which fire when "bill clinton" is consciously perceived</li></ul>

Question 9

Q

What is 2nd theory: Global Workspace Theory

Answer

A

<ul> <li>Information is loaded into workspace and powerful cognitive processes can make use of it</li> <li>Act of transmitting these data from working memoryto the functional modules (e.g., percept, cognition, motor areas)giverise to consciousness.</li></ul>

[Not that a separate system (man in the head) “sees” information in the workspace to make it conscious.]

Question 10

Q

What, and where is the global workspace in the brain?

Answer

A

Consciousness:

<ul> <li>Signal is sufficiently strong to “break into” prefrontal cortex, allowinginformation to be transmitted between other brain areas</li> <li>Stimuli will have unconscious processing before moving into PFC (which will have consciousness)</li></ul>

Question 11

Q

Initial fMRI studies on Consciousness

Answer

A

A summary of studies showing areas of parietal and frontal cortex with activation correlated with changes in visual awareness

(Sensory processing /=/ consciousness)

Question 12

Q

What did“No report” paradigms find?

Answer

A

Activity in the frontal part of the brain appears to be important for the response component of the task. If participants don't have to respond, frontal becomes inactive

Suggest parietal area is the key.

Question 13

Q

What is the Integrated Information Theory?

Answer

A

<ul> <li>Consciousness = Integrated Information</li> <li>The greater the number of mutually exclusive possible states a system can hold, the more conscious it is.</li> <li>Any system with integrated information is conscious (including computers)</li></ul>

Question 14

Q

Integrated Information: Experiences

Answer

A

<ul> <li>Our experience is integrated and unified <ul> <li>It can’t be experienced as its components (contrast, location, content etc)</li> </ul> </li> <li>Our experience is informative <ul> <li>It is specific and distinct from alternative experiences</li> <li>Total black (an absence of sensory input) is informative for what it is not [Something vs Nothing]</li> </ul> </li></ul>

Question 15

Q

Integrated Theory: Cerebellum and Gut

Answer

A

<ul> <li>Cerebellum andgut show limited signs of consciousness, despite having millions of neurons.</li> <li>IT suggests cerebellum and gut are not conscious because the neurons are not connected to each other like they are in the cortex.</li> <li>Any system with integrated information is conscious</li></ul>

Question 16

Q

Limitations of Integrated Theory

Answer

A

Contradictions

<ul> <li>Theory states that consciousness=integrated information andsystem will be conscious if phi > 1</li> <li>Predicts gut has thousands of micro-conscious units, but our brains can't accessseparate gut consciousness?</li></ul>

Time Scales

<ul> <li>Many bodily systems signal at the different speed</li> <li>Predicts we have multiple layers of consciousness overlaid in different time scales?</li></ul>

Question 17

Q

Theory vs Theory

Answer

A

<ul> <li>Sparse coding requires a network of specific cells to fire for consciousness. Does not say where in the brain or to what extent networks integrate</li> <li>Potentially consistent with Global work space or IIT</li></ul>

<ul> <li>Involvement of distributed frontal brain regions consistent with IIT, Global Work Space and potentially sparse coding (if sparse network is distributed widely)</li></ul>

Question 18

Q

Summary of Theories

Answer

A

All of these theories simply state that consciousness is the result of “X” condition, but they do not explainwhy “X” condition should lead to a conscious experience.

Question 19

Q

SAQ. What is binocular rivalry and why is it a good tool for consciousness research?

Answer

A

Binocular rivalry is the presentation of 2 stimuli simulataneously but we can only be conscious of1 at a time.

It is good because withchanges in percept, we can use neuroimaging and neural activity for example toidentify what is assoicated with the percept change.

Question 20

Q

SAQ. What is Backward Maskingand why is it a good tool for consciousness research?

Answer

A

Actual stimulus is the same but by manipulatingthe time gap between target and mask, we sometimes don't perceive the target.

Hence, can use neuroimaging or neural recording to compare responses between when we see target and we don't see target and what is associated with consciousness.

Question 21

Q

What is the question in reference to "levels of consciousness"

Answer

A

Changes in the intensity or degree of consciousness.

Even if we can answer this question, we still won't know about the content of the person's experience (e.g., what does 'less consciousness' feel like?)

Question 22

Q

What are 2 dimensions of consciousness

Answer

A

Awareness: Levelsof consciousness

Vigilance: Awake behaviour, eyes open

Question 23

Q

If we want to measure consciousness, what can we not rely on?

Answer

A

Measure of consciousness that does not rely on sensory processing or behaviour as consciousness can exist with undeveloped/impaired sensory processing and/or motor output.

Question 24

Q

Problem of diagnosis in acute brain injury?

Answer

A

<ul> <li>High levels of misdiagnosis in Coma, Vegetative State (VS), and Locked-in Syndrome as all 3 states are “non-responsive” despite different levels of awareness & cognition</li></ul>

In cases like brain death, it is clear it is brain death if there is total loss of activity throughout the brain. Normally, if you put someone in the brain scan you can still see activity in the brain

Question 25

Q

Evidence of consciousness in VS? (3)

Answer

A

<ul> <li>Healthy people and a non-responsive VS patient (GCS = 4) was asked to imagine “playing tennis” or “visiting rooms in your house”</li> <li>Brain activity in the VS patient was found to be similar to the healthy people</li> <li>Even if people failed, they show minimal consciousness</li></ul>

Question 26

Q

What is consciousness not linked to? (2)

Answer

A

Level of consciousness:

<ul> <li>Not directly linked to neural activity (though zero activity= zero consciousness) (e.g., sleep)</li> <li> Not directly linked to amount of neural synchrony (e.g., anesthesia show increase synchrony as consciousness is lost) </li></ul>

Question 27

Q

IIT's argument on level of consciousness. (2)

Answer

A

Integrated information theory (IIT)

<ul> <li>Greater the complexity of the neural signal = Greater consciousness</li> <li>Highly complex brain activity patterns = Greater consciousness</li></ul>

Question 28

Q

How does IIT assessconsciousness

Answer

A

IIT reduces complexity to a single score to separate those that are conscious from those that are not

<ul> <li>Stimulate brain with TMS > Record "complexity" of brain with EEG > Compress (Remove redundant information) > Complexity Index</li></ul>

"Complexity" is defined by information (e.g., football fan). The more random it is, the more complex it is.

Question 29

Q

How do we separate out individuals in different states of consciousness?

Answer

A

Complexity index gives a number between 0 and 1 and there is a cut off.

If the complexity of the brain’s response is measuredand they get a complexity index below the cut off, then they are considered unconscious

<ul> <li>LIS = Above cut-off</li> <li>VS and Coma = Below cut-off</li></ul>

Question 30

Q

Deep brain stimulation and coma

Answer

A

Electrical stimulation to the Thalamus (Relay Centre)has been used to successfully “jump-start consciousness” in people in a vegetative or minimally conscious state.

Question 31

Q

Anaesthesia and consciousness

Answer

A

Anesthetic drugs are used everyday but their mechanism of action remains a mystery.

However, it impacts the thalamus (often deactivated in VS and some of the first to reactivate when recovered)

Question 32

Q

What does IIT and Global Workspace Theory say about cortico-thalamic loops?

Answer

A

Integral part of many theories of consciousness

<ul> <li>IIT: Connections from many areas goes through the thalamocortical system (Integrated Hub)</li> <li>Global Workspace Theory: Thalamocortical area is the workspace</li></ul>

Question 33

Q

Consciousness and psychedelics

Answer

A

Uni-demsnional level-based account might be too simplistic to account for the full range of human conscious.

Might have multiple dimensions of consciousness

Question 34

Q

Ethical/Philosophical questions of Consciousness (4)

Answer

A

<ul> <li>How much faith should we put in a brain signal measure of consciousness?</li> <li>Would such a measure be relevant to treatment of Animals? Babies or Elderly patients with dementia?</li> <li>What if it there was an age, race or gender that appeared to have higher levels of consciousness?</li> <li>If a complexity measure is identified, then the potential to recreate that in a robot or computer is an obvious consequence. Do we need to consider the ethics of robotic “life,” or an internet with feelings</li></ul>

Question 35

Q

3. One famous study uses fMRI to assess the level of brain function in a Vegetative State patient. What was the main finding of this study? What can we conclude from the finding?

Answer

A

They found that VS patients and healthy participants had similar regions of activation when told to imagine "playing tennis" or "visiting rooms in your house". Even if the VS patients 'failed' the task, fMRI still revealed brain activity. This suggests that VS patients still have some level of consciousness.

Question 36

Q

What are the basic hallucinogen effects (4)

Answer

A

<ul> <li>Rarely cause full hallucinations but commonly induce striking perceptual distortions.</li> <li>Mystical experiences & altered sense of self.</li> <li>Strongly influenced by personal and environmental context.</li> <li>Negative side effects of all hallucinogens is predominately due to the “drug experience”. These drugs are non-toxic and non-addictive.</li></ul>

Question 37

Q

How do hallucingents cause motion illusinons?

Answer

A

Psychedelics impact how individual signals are integrated (Visual, etc...)

Question 38

Q

Psilocybin current uses in research (4)

Answer

A

<ul> <li>Clinical Therapy: To test as a possible treatment for a range of conditions including depression, addiction, OCD etc</li> <li>Psychopharmacology: To understand the role of the natural neurotransmitters in healthy perception & cognition.</li> <li>Model Psychosis: the use of hallucinogens to induce temporary “psychosis-like” episodes in the healthy people to understand the mechanisms underlying clinical psychosis.</li> <li>Consciousness: Recent increasing focus of research on altered states of consciousness and understanding the breadth of human experience.</li></ul>

Question 39

Q

What receptor does Psychedalics activate? And what does this receptor do?

Answer

A

The exact action of these drugs is not known. However, the majority of hallucinogens activate specific serotonin receptors located across the cortex, especially the5-HT_2Areceptor

<ul> <li>5-HT_2Acauses hallucinations and alters conscious experience</li></ul>

Question 40

Q

What are the consequences of activating the 5-HT_2Areceptor? (2)

Answer

A

Consequence of activating 5-HT_2A receptors are (i.e. hallucinogens cause):

<ul> <li>Increase in overall excitation in the cortex</li> <li>Increased amplitude and frequency of activity of neurons travelling from the cortex to the thalamus <ul> <li>E.g. Neurons that code for colour inappropriately sends information to thalamus</li> <li>Disrupts corticothalamic loops, exactly how this happens is a matter of debate. One theory suggests hallucinogens primarily cause more information being sent from the cortex to thalamus</li> </ul> </li></ul>

Question 41

Q

What didLSD Imaging Studies find? (2)

Answer

A

<ul> <li>Visual imagery correlated with increased visual cortex resting state functional connectivity</li> <li>Ego dissolution correlated with reduced default mode network integrity</li></ul>

Question 42

Q

What are thehallucinogen effects on perception. Are they random?

Answer

A

Effects are unusual but not random (also not always pleasant)

Question 43

Q

What are the 3 key things in Consciousness science?

Answer

A

<ol> <li>Perception</li> <li>Self/Unity</li> <li>Cognitive/function</li></ol>

Question 44

Q

Effects of hallucinogens on perception

Answer

A

<ul> <li>Subjective: Greater volume or variety of contents</li> <li>Psychophysics: Measurable reducton on some stuff</li></ul>

Question 45

Q

Effects of hallucinogens on cognition

Answer

A

Cognition: Reduced

<ul> <li>Communication: Reduced</li> <li>Attention & Working Memory: Reduced</li></ul>

Question 46

Q

Effects of hallucinogens on self/unity

Answer

A

<ul> <li>Subjective: Unclear</li> <li>Psychophysics: Less</li></ul>

Question 47

Q

Is it appropriate to consider psychedalics a higher state of consciousness?

Answer

A

Unclear. But it argues against the uni-dimensional view of consciousness

Question 48

Q

What are the methodological challenges of meditation

Answer

A

<ul> <li>Many types of meditation, and every person does things differently <ul> <li>e.g., mantra vs visual</li> </ul> </li> <li>Many placebo ingredients (e.g., in-group, common goal, effortful, strong belief it is helpful, population bias) so it is hard to identify the “important” bits <ul> <li>Everyone thinks that meditation is good</li> </ul> </li> <li>Studies using “active controls” such as quietly listening to music for 30min every day, often lead to similar changes as "meditation controls"</li></ul>

Question 49

Q

Meditation and Stress (3)

Answer

A

<ul> <li>Evidence map of meditation suggests some positive effects</li> <li>Brain areas involved in attention control, emotion regulation and self-awareness are shown to be associated with meditation</li> <li> Number ofpsychological and neurobiological effects of meditation have been linked to a reduction in the stress response </li></ul>

Question 50

Q

What did Mindfulness-Based Cognitive Therapy on depression do? (2)

Answer

A

<ul> <li>Mindfulness-Based Cognitive Therapy (MBCT) reduced relapse rate for depression</li> <li>The more severe the initial depression (higher z-score values) greater the benefit of MBCT.</li></ul>

Question 51

Q

Lecture Summary

Answer

A

<ul> <li>The majority of hallucinogens activate a specific group of serotonin neurons that alter sensory and cognitive function by disrupting the flow of information between the cortex and thalamus</li> <li>Meditation has profound effects on an individual’s psychological state but there is still an absence of detailed scientific knowledge about the biological processes associated with meditation.</li> <li>Some evidence exists that meditation can impact attention/cognition and improve outcomes for major depression.</li></ul>

Question 52

Q

Describe two methodological obstacles associated with meditation research.

Answer

A

1.) It is difficult to control as people meditate differently; some do imagery, some do a mantra.

2.) Many placebo ingredients such as in-group and population bias, making it difficult to identify 'important' bits and what really distinguishes meditation from other things.

Question 53

Q

4. Converging lines of evidence suggest that “cortical thalamic loops” might be important in consciousness. Describe the functional role of the thalamus that is repeatedly emphasised in current theories of consciousness.

Answer

A

Thalamus connectsdifferent areas of the brain and acts as a relay centre. It is thought that our sense of consciousness is established here.

Question 54

Q

What is Neuroethics

Answer

A

<ul> <li>Neuroethics: Social, legal, ethical and policy implications associated with advances in neuroscience.</li> <li>Increased knowledge leads to greater prediction, understanding and possibilities for manipulation.</li></ul>

Question 55

Q

The problem with understanding

Answer

A

<ul> <li>Increased understanding of how “abnormal” brain structure/function impacts behaviour the extent to which an individual is seen to be in control or responsible for their behaviour can be reduced.</li> <li>Will society develop different expectations based on physical (dis)ability of the brain?</li></ul>

Question 56

Q

The problem with manipulation

Answer

A

The pharmaceutical industry invests trillions into drug development - Aim to increase positive side effects & reduce negative side effects

Drugs are available NOW that improve function beyond healthy. They “enhance” rather than treat.

Question 57

Q

Treamtent vs Cognitive Enhancement?

Answer

A

<ul> <li>Treatment <ul> <li>Reducing clinical symptoms and restoring normal function (i.e. depression, Alzheimer’s etc)</li> </ul> </li> <li>Cognitive enhancement <ul> <li>Expanding or augmenting the human capacity to think, feel, react, and remember, ‘beyond the species-typical level or statistically-normal range of functioning’.</li> </ul> </li></ul>

Question 58

Q

What isModafinil

Answer

A

<ul> <li>Designed to treat narcolepsy, a medical condition involving excessive daytime fatigue and sleep.</li> <li>Mechanism of action unknown but suggests involvement of Dopamine and Noradrenaline.</li> <li>In healthy people reduces the need for sleep (without obvious side effects or need to catch-up-sleep)</li></ul>

Question 59

Q

What is the enhancement drug use rates at University

Answer

A

Self reports of drug use for enhancement over the past 12 months show relatively low prevalence but broad range of use.

Prescription, Lifestyle, Illicit

Question 60

Q

Modafinil – ethical issues

Answer

A

<ul> <li>“Medicalization” of normal function <ul> <li>Normal life struggles are now becoming medical conditions e.g., Shift work sleep disorder. Official diagnosis can be important for medical benefits.</li> </ul> </li> <li>Off-label drug use <ul> <li>Use of drugs for purposes they were never designed or tested for.</li> </ul> </li> <li>Explicit Coercion <ul> <li>If drugs improve productivity employers may force workers to take them (i.e. the army or other industries).</li> </ul> </li> <li>Implicit coercion <ul> <li>Your boss might not force you to take drugs but if everyone else is doing it, then they might be necessary to compete.</li> </ul> </li> <li>Distributive justice <ul> <li>Are we increasing the class divide with chemical “haves” and “have nots”?</li> </ul> </li> <li>Authenticity & personal achievement <ul> <li>Enhancements = Short cuts to hard work?</li> <li>Tutoring vs Drugs?</li> </ul> </li></ul>

Question 61

Q

Future Cogntiive Enhancements

Answer

A

<ul> <li>Memory (AD)</li> <li>Attention (ADHD)</li></ul>

Developments on this clinical groups will aid memory and attention.

Question 62

Q

Are drugs bad?

Answer

A

You can’t ask this in isolation. You have to think about it in terms of the brain, the individual, development of a person and the impact on society

Question 63

Q

Does brain stimulation work?

Answer

A

No replication or consistent effects. Meta-analyses suggest on average, it does nothing.

Question 64

Q

Future concerns?

Answer

A

<ul> <li>Trust and bonding <ul> <li>Oxytonin pill for parent-child?</li> </ul> </li> <li>Sleep <ul> <li>Drugs that reduce the need for sleep be mandated for some jobs?</li> </ul> </li> <li>Memory <ul> <li>If more education is better should we add memory drugs to the drinking water so that everyone will remember more (i.e. 5% more) of what they learn?</li> </ul> </li></ul>

Answer 65

A

A danish study found areas with higher lithium in drinking water had far low rates of dementia.

Implication is we can potentially introduce lithium into all drinking water as an intervention against dementia.

Answer 66

A

Include any of the following with a brief amount of detail:

<ul> <li>Specific Postures, (species specific)</li> <li>Reduced activity, (some movements when rolling over etc, although these are likely occurring during brief arousals/awakening)</li> <li>Reduced responsiveness, (still do respond to most stimuli but need higher stimuli than during wake)</li> <li>Rapidly reversible, (unlike Coma/unconscious states)</li> <li>Eyes closed, (when eyes and eyelids present – not all species have eyes)</li> <li>Behavioural preludes (dog/cat walking in circles etc)</li></ul>

Answer 67

A

The CSF of sleep deprived dogs was injected into the brains of well rested dogs and induced sleep in the donor animals.

This led to the theory that there was a toxin in the body that built up during wakefulness and was removed during sleep.

Answer 68

A

Cataplexy is a period of muscle weakness or paralysis of skeletal muscles (but not eyes or breathing muscles) that occurs in response to strong emotions in many patients with narcolepsy.

It can be treated with antidepressants which supress REM, or sodium oxybate which dramatically improves sleep quality over a few weeks.

Answer 69

A

Cetaceans show unihemispheric sleep in which one half of their brain sleeps at a time. This likely enables them to keep swimming/breathing while asleep. They also show no REM sleep.

The mothers and calves have greatly reduced/absent sleep in the immediate post-partum period and do not show sleep rebound effects following this period.

Answer 70

A

Local sleep refers to the fact that different parts of the brain may be in different sleep-wake states at the same time.

Any of the following evidence could be used:

<ul> <li>intracranial electrode recordings in epilepsy patients have shown different sleep stages at the same time,</li> <li>SWS unfolds regionally (frontal regions first then works backwards),</li> <li>SWS has been shown to be regionally distributed in a use dependent fashion after arm immobilisation or tasks that use a specific known area of the brain.</li> <li>Sleep walking and sleep talking are weaker lines of evidence, as are sleep inertia and lapses in performance that occur right after awakening, but they do still support the concept.</li></ul>

Answer 71

A

Social pain/bereavement activates the same regions of the brain as physical pain.

Therefore, some painkillers would be expected to reduce activity in the brain areas responsible for pain generation and therefore may make the person feel slightly better.

Answer 72

A

<div>Any of the following:<ul> <li>Blood/brain CO₂ levels <ul> <li>RTN</li> </ul> </li> <li>Blood oxygen (O₂) levels <ul> <li>RTN via peripheral chemoreceptors</li> </ul> </li> <li>Lung irritants and/or overstretching of the lungs <ul> <li>DRG</li> </ul> </li> <li>Emotions, Pain, Body Temperature, Volitional inputs <ul> <li>PRG</li> </ul> </li> <li>Exercise <ul> <li>PRG directly (in anticipation of exercise for e.g.,) and via. increased CO₂ through RTN</li> </ul> </li></ul></div>

Answer 73

A

Binocular rivalry is the presentation of 2 stimuli simulataneously but we can only be conscious of 1 at a time.

It is good because with changes in percept, we can use tools like neuroimaging and neural activity to identify what is associated with the percept change.

Answer 74

A

They found that VS patients and healthy participants had similar regions of activation when told to imagine "playing tennis" or "visiting rooms in your house", demonstrating they could understand and perform the task.

Even if the VS patients 'failed' the task, fMRI still revealed brain activity, suggestingthat VS patients still have some level of consciousness.

Answer 75

A

The thalamus acts as a relay centre connecting many parts of the brain.

In integrated information theory, thalamus acts as the integrated hub as connections from many areas goes through the thalamocortical system.

In global workspace theory, thalamocortical area acts as the workspace that gives rise to consciousness.

Answer 76

A

1.) It is difficult to control as people meditate differently, which may have different effects.

2.) Many placebo ingredients such as in-group and population bias, making it difficult to identify 'important' bits and what really distinguishes mediation from other things.

Answer 77

A

Myasthenia Gravis, severe muscle weakness, is caused by the production of antibodies thatbind to Acetylcholine receptors,

Acetylcholine cannot bind to the membrane to produce action potentials and contraction on the muscle, inhibiting muscle movement and causing muscle weakness.

Answer 78

A

The efference copy means you cannot tickle yourself.

Unlike healthy controls, schizophrenia patients with auditory hallucinations experience the same degree of ticklishness irrespective of whether a tickle is self-generated or externally generated.

This suggests schizophrenia may result from faulty efference copies of speech, movement and thought.

Answer 79

A

<ul> <li>In the forced desynchronny protocol, participants had appropriate amount of SWS (processes S) regardless of time of day (Process C).</li> <li>SWS in naps during the day was correlated to time-spent awake, irrespective of time of day. And SWS during that night would be reduced.</li> <li>SWS occuring in the dayafter a night of deprivation reflects the appropriate rebound effects, irresepctive of time of day.</li> <li>Animals with ciradian pacemaker cells removed show appropriate homeostatic drive</li> <li>Circadian rhythm can be phaseshifted without affecting SWS, such as when travelling to different time zones.</li></ul>

Answer 80

A

In the forced desychrony protocol, a slight interaction between the circadian and homeostatic systems are often observed, where SWS when the sleep time is out of circadian rhythm is reduced.

Phase shifting ability of light is much more effective if the person was not sleep deprived, suggesting an interaction.

Answer 81

A

A Danish study found that areas with higher levels of lithium in drinking water were associated with lower rates of dementia.

For public policy, this implies adding lithium into drinking water may act as intervention against dementia.

Answer 82

A

1.) Serious physiological consequences ensure after extended periods without sleep, such as in the study where sleep deprived rats died.

2.) Accomodations has been made to permit sleep across multiple environments and lifestyles across species, suggesting that it has significance.

3.) Numerous brain regions have been evolved to maintain sleep in the system.

4.) Sleep has persisted through evolution despite appearing maladaptive with respect to other functions such as food.

5.) Sleep occurs across many species such as primates, birds, and reptiles, and it also probably occurs in amphibians, fish and invertebrates.

Answer 83

A

At birth, about 16 hours is spent asleep with 50% of that in REM.

Across first 2 years, amount of REM reduces and consequently total sleep reduces such that about 25% is spent in REM.

From 2 years to adoloscene, both REM and NREM reduces and by adoloscene, our total sleep time is approximately 8 hours.

From adoloscene onwards, thisremains relatively stable till old age.

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Week 11-12 (Consciousness) Flashcards

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