Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PSYCH 275 > Chapter 15: Sleep and Consciousness > Flashcards

Chapter 15: Sleep and Consciousness Flashcards

1
Q

Why is there such a huge debate surrounding the definition of consciousness? What are the two main ways we study consciousness?

A

Some researchers think that it is inaccessible to research because it is not a tangible/physical thing we can study. We can only gain information about consciousness through introspection, where people report on their experiences. We also study it through sleep, as we are partially conscious when we sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is sleep?

A

Partially conscious and partially unconscious, it is a period of enforced nonproductivity and vulnerability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the evidence for the restorative function of sleep?

A

Animals with a higher metabolic rate sleep more, to restore their energy stores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the adaptive hypothesis of sleep?

A

This theory states that the amount of sleep an animal engages in depends on the availability of food and safety. If there is a large availability of food and low safety then the animal will continuously eat throughout the day and keep an eye out for predators, and will not sleep much. Predators will sleep more as they will eat one big meal and they do not need to protect themselves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are two points that illustrate the importance of sleep?

A

Shift workers performance: those on night shift are less productive than those during the day as they fail to adjust to a new sleep/wake cycle. They also usually do not maintain their work sleep schedule when not working therefore hindering them more
Long term sleep deprivation studies show daylight savings messes with peoples sleep/wake cycle, and sleep quality is better when the days are longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is our circadian rhythms? What are these rhythms that are biologically programmed called? What brain region is responsible for maintaining the circadian rhythm?

A

Out circadian rhythm is our biologically programmed (endogenous) rhythmicity that is controlled by environmental cues. The suprachiasmatic nucleus (SCN) is a region of the hypothalamus that acts as the main biological clock by controlling the production and release of melatonin (makes us sleep). It keeps time and regulates cellular activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does lesioning the SCN do?

A

Leads to many short sleeps, instead of one long one in the innate 24 hour circadian rhythm period. It regulates when you sleep NOT how much

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are entraining stimuli? (Zeitgebers)

A

Timegivers, light is the primary entraining stimuli, bright lights while working and a dark room when sleeping maintains our natural circadian rhythm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the difference in time between the human circadian rhythm in the presence versus absence of environmental stimuli?

A

In the presence of environmental stimuli humans have a 24 hour circadian. In the absence of entraining stimuli humans naturally shift towards a 25 hour circadian rhythm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is melatonin and what is its role in sleep?

A

This is a hormone produced and released in the SCN, and it controls sleepiness. Light resets the biological clock everyday by suppressing the release of melatonin secretion. Constantly being around bright lights also suppresses melatonin release including before bed therefore harder to sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

If an animal does not use light to regulate sleep what do they use?

A

The moon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the pathway that leads to the release of melatonin before bed?

A

SCN signals the pineal gland to release melatonin which leads to sleepiness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a ultradian rhythm? What is an example?

A

A rhythm that is less than a day in length (hormone production, urinary output, alertness). The basic rest and activity cycle if a rhythm that is 90-100 minutes long, and explains the dip in productivity in the middle of the day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is brain activity like when asleep? What does this tell us about the triggers of sleep?

A

Brain activity is frequent and high intensity, your brain does not shut off when you sleep. This means that sleep is not necessarily triggered by the running out of energy, instead it may be turned on by some and turned off by others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is an EEG used for sleep? What is it paired with?

A

Electrodes on the surface on the head to measure brain activity during sleep. My be paired with an electrooculogram to measure eye movement as well as a electromyogram to measure muscle activity in the jaw.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the first stage of sleep? What appears here?

A

Lasts 1-10 mins, transition to light sleep, get transition from beta to alpha to theta waves as we fall asleep. Here we get hypnic/myoclonic jerks as well as hypnagogic imagery (feel like falling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the second stage of sleep? What appears here?

A

10-25 minutes, deeper sleep, brain waves decelerate, heart rate slows, body temp decreases, muscles relax and eye movement cease
Sleep spindles: 1-2 seconds of rapid brain activity
K-complexes: neural excitation followed by neural inhibition (peak followed by dip)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is stage 3/4 sleep? What happens?

A

This is referred to as slow-wave sleep (30 mins), and we get the appearance of delta waves, and this is the restorative stage of sleep, where it is important to feel rested.
We get sleep walking, bed wetting as well as night terrors here. Muscles are relaxed but still usable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the 5th stage of sleep? What do brain waves here mimic?

A

REM sleep, occupies about 20-25% of our sleep cycle, rapid eye movement, irregular pulse and muscle paralysis, get most vivid and story like dreams here, each cycle lasts between 20-1 hour and lengthens each time that we go back into it. Here the brainwaves mimic the same waves seen while awake (beta waves)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the order of the sleep cycle?

A

1 –> 2–> 3/4 –> 2 –> 5 (REM) –> 2 –> 3/4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Does your time in REM increase or decrease each cycle?

A

INCREASE

22
Q

What are the three hypotheses for why we sleep? Which one is best?

A

Hypothesis 1: sleep evolved to conserve organismsenergy (BEST)
Hypothesis 2: immobilization during sleep is adaptive because it reduces danger
Hypothesis 3: sleep helps animals to restore energy and other bodily resources

23
Q

What are the functions of slow-wave sleep?

A

Restoration of the brain (supported because sleep deprivation produces cognitive deficits)

24
Q

What are the functions of REM sleep?

A

Rebound phenomenon suggests need for REM sleep, and it also promotes consolidation of memories

25
Q

How is REM sleep a component of memory and learning?

A

After learning, if REM sleep decreases then we get decreased retention, we NEED REM sleep to retain what we have learned, because the things we learn replay in our head during REM sleep.

26
Q

What happens to brain waves during consolidation?

A

Synchronized peaks of theta waves

27
Q

How long after learning does info move to long-term memory? What brain region is involved in this?

A

4-7 days, moves to the hippocampus, and brain waves move out of synch again as you are not consolidating

28
Q

What is the synaptic homeostasis hypothesis?

A

The idea that synaptic pruning and removal of junk happens during sleep and makes memories and learning easier to achieve. Your dendrites decrease and therefore have less complex connections

29
Q

What are the brain arousal centers? (2) What happens if you lesion these areas?

A

Brain arousal centers send activating signals to higher levels of the brain
Pedunculopontine and laterodorsal tegmental nuclei (PPT/LDT): fire most rapidly during wakefulness and REM sleep, and slowest during non-REM sleep (why we get the same waves when awake and in REM)
Second branch: many basal forebrain areas
Lesioning these areas leads to temporary decrease in wakefulness but we eventually recover as these areas are not the only ones regulating awakeness

30
Q

What are the non-REM sleep controls? (2)

A

Ventrolateral preoptic nucleus (VLPO): an area of the hypothalamus that inhibits the arousal network (PPT/LDT), and neurons fire 2-4 times faster during non REM sleep in this area, and even more as sleep deepens
Parafacial zone in the medulla maybe

31
Q

What are the REM sleep controls?

A

PGO waves: high voltage brain waves travel from the PONS through the lateral GENICULATE nucleus of the thalamus to the OCCIPITAL area. Begins 80s before start of REM period and initiates the EEG desynchrony of REM sleep.
Sublateral nucleus (SLD): in the pons, governs the switching from REM to non-REM sleep, when active we are in REM

32
Q

What is insomnia? What can it be caused be?

A

Inability to sleep or gain adequate-quality sleep, to the extent that the person feels inadequately rested. CHRONIC LACK, can’t fall asleep or stay asleep, not enough stage 3/4 sleep, hyperarousal during sleep so you wake up more
Most common sleep disorder, more common in women
Can be caused by stress, taking depressants, or when you stop taking sleep aids

33
Q

What is sleep walking? What are its triggers? Is it genetic?

A

Somnambulism: originates during deep sleep and results in walking or performing other behaviors while still mostly asleep. Triggered by stress, alcohol or sleep deprivation
There is a genetic component, if you are the child of someone who sleepwalks you have a 50% chance of sleepwalking due to the presence of a specific allele

34
Q

What is narcolepsy?

A

Disorder where people fall asleep suddenly during the day time and go directly into REM sleep. The border between asleep and awake is blurred and they are usually deficient in orexin (stay awake hormone). BUT at night they sleep like everyone else

35
Q

What is cataplexy?

A

Disorder which the person has a sudden experience of one component of REM, atonia (loss of muscle tone), and they fall to the floor paralyzed but fully awake
Often comorbid with narcolepsy

36
Q

What is REM sleep behavior affective disorder? What could this be a precursor for?

A

People are uncharacteristically physically active during REM sleep, often to the point of injuring themselves or their bed partners. People may act out vivid dreams, more common in men and in people who smoke/drink heavily or work in welding/pesticides.
Could be a precursor for Parkinson’s

37
Q

What does consciousness refer to? What are the three structures that appear to be involved in consciousness?

A

State of awareness/focus, short term memory, sense of self, spectrum of consciousness. The ACC, the AIC, and the central lateral thalamus appear to be involved, NOT A SINGLE STRUCTURE

38
Q

What are the two networks that appear to be involved in consciousness?

A

Salience network and central executive network

39
Q

What is the salience network?

A

A group of brain regions that detect significant stimuli that require attention, determines whether info is important and attributes attention. Includes the AIC and the ACC

40
Q

What is the central executive network? How does the salience network work with this one?

A

Group of brain regions that control attention and working memory. The salience network bounces back and forth between the default mode network (awake/REM) and the central executive network (for activities requiring attention)

41
Q

What is awareness? How is it studies?

A

Awareness is the content of consciousness (hard to define).
Studied by monitoring brain activity to word exposure. If we do not recognize the word only the visual cortex is activated, but if we recognize the word then the visual and the lateral PFC, and the PPC are active

42
Q

What is attention?

A

The process of selecting our awareness targets, the verb/process of attributing awareness
The brains means of allocating limited resources by focussing on some neural inputs to the exclusion of others

43
Q

What are the two primary networks involved in attention?

A

Dorsal attention network (goal-directed control) and ventral attention (stimulus demands)

44
Q

What is agency? What test is usually used to determine whether a species has agency?

A

Attribution of an act or effect to ourselves rather than to an external force. Use the rouge test to determine whether and animal has agency, seen in chimps, humans, elephants, porpoises and magpies but NOT monkeys

45
Q

What brain regions are involved in the sense of self?

A

ACC and the insula are used in self-recognition, self-description, and memories

46
Q

What does transcranial magnetic stimulation to the parietal area do in terms of self?

A

Reduces the patient’s ability to use self-descriptive words, despite being able to describe others perfectly well.

47
Q

What three things are included in the self?

A

Body image (our body and its parts), mirror neurons (fire when we see others emotions) and memory (long term memory not short)

48
Q

What three things are mirror neurons important for?

A

Social understanding, empathy, understanding others intentions

49
Q

What are split brain patients? What are the two interpretations as to how split brain patients?

A

Patients who have had the corpus callosum cut to prevent epileptic seizures (usually), and their bodies may behave in two distinct ways
#1: The major/language dominant hemisphere is the arbiter of consciousness and that the minor hemisphere is an automaton
#2: Each hemisphere is capable of consciousness and severing the corpus callosum divides consciousness into two selves (RT/LT)

50
Q

What is dissociative identity disorder?

A

Involves a shift in consciousness and behaviour that appear to be distinct personalities or selves.
Some thing it is a form of PTSD as they both have similar brain changes

PSYCH 275 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions