2 - Biopsychology Flashcards
(131 cards)
1
Q
Describe the divisions of the nervous system
A
Nervous system split into CNS & PNS
CNS split into Brain & Spinal Chord
PNS split into Autonomic & Somatic
Autonomic split into Sympathetic & Parasympathetic
2
Q
Explain the role of the brain in the CNS
A
The centre of all awareness. Responsible for core information processing.
Outer layer - cerebral cortex - highly developed and distinguishes our higher mental functions
3
Q
Explain the role of the spinal chord in the CNS
A
Extension of the brain.
Responsible for reflex actions.
Helps the brain monitor and regulate body processes
4
Q
Label the 6 parts of the brain
A
Frontal lobe Parietal lobe Occipital lobe Temporal lobe Cerebellum Brain stem
5
Q
What are all the lobes of the brain together called?
A
The cerebrum
6
Q
What does CNS stand for?
A
Central Nervous System
7
Q
What does PNS stand for?
A
Peripheral Nervous System
8
Q
What is the role of the PNS?
A
Consists of all the nerves that are external to the CNS.
Helps to relay impulses from the CNS to parts of the body, and vice versa.
9
Q
Explain the ANS
A
Autonomic Nervous System.
Part of the PNS.
Governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses.
10
Q
Explain the SNS
A
Somatic Nervous System.
Part of the PNS.
Controls muscle movement and receives information from sensory receptors.
11
Q
Explain the 2 key differences between the CNS & PNS
A
CNS’ primary purpose is to organise and analyse information whereas PNS is to follow CNS commands.
CNS controls reflex (involuntary) actions whereas PNS is responsible for voluntary actions
12
Q
What are the 2 sub-sections of the ANS?
A
Sympathetic
Parasympathetic
13
Q
What does the sympathetic nervous system do?
A
Increases heart & breathing rates Dilated pupils Inhibits digestion & salive production Contracts rectum Prepares fight or flight response Secrets noradrenaline Decreases use of non-vital organs
14
Q
What does the parasympathetic nervous system do?
A
Decreases heart & breathing rate Constricts pupils Stimulates digestion & saliva production Relaxes rectum Prepares rest and digest response Secretes acetylcholine Relaxes the body Restores organs to ordinary processes
15
Q
Define neurone
A
A specialised cell which carries neural information around the body
16
Q
What are the 3 types of neurones and what are their roles?
A
Sensory - carries messages from sensory receptors to the spinal chord and brain (CNS)
Relay - connects the sensory neurones to the motor neurones and other neurones
Motor - connects the CNS to effectors such as muscles and glands
17
Q
List 8 parts found in a motor neurone
A
Nucleus Dendrites Cell body Axon Myelin sheaths Node of ranvier Schwarns cells Axon terminal
18
Q
Define dendrite
A
Branched structures from the cell body that carry impulses from adjacent neurones to the cell body
19
Q
Define axon
A
Carries nerve impulses from cell body down the length of the neurone
20
Q
Define cell body
A
Includes the nucleus containing genetic material of the cell
21
Q
Define what nodes of ranvier are
A
Gaps in the myelin sheath which sped up the transmission by making it jump across the gaps in the axon
22
Q
Define myelin sheath
A
Fatty layer that protects and insulates the axon and the electrical impulse, speeding up transmission
23
Q
Define axon terminals
A
They communicate with the next neurone in the chain across the synapse
24
Q
What are the 2 types of effects that neurotransmitters have in neighbouring neurones?
A
Inhibitory & excitatory
25
Give an example of an inhibitory neurotransmitter
Serotonin inhibits neurones which are receiving the impulses, making the neurone “negatively charged” and less likely to fire.
26
Give an example of an excitatory neurotransmitter
Adrenaline excites receiving neurones making them more likely to fire.
27
Define summation
The net calculation of adding up inhibitory and excitatory synaptic inputs to determine the likelihood of a cell firing due to it receiving both an inhibitory and an excitatory neurotransmitter
28
What is the endocrine system?
A network of glands in various places in the body which manufacture hormones.
It works with the nervous system to regulate physiological processes however, the endocrine system is much slower.
29
How are hormones manufactured?
They are secreted by endocrine glands. They travel through the bloodstream to target organs
30
What are the 2 glands in the endocrine system that psychology is interested in?
```
Pituitary glands (controlled by the hypothalamus in the brain)
Adrenal glands
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31
Name 8 different glands in the endocrine system
```
Pituitary gland
Hypothalamus
Thyroid gland
Parathyroid gland
Adrenal glands
Pancreas
Ovaries
Testes
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32
Describe the pituitary gland (roles, structure, hormone production etc.)
Located in the brain
Known as the “master gland”
Controls the release of hormones from all the other endocrine glands in the body
Controlled by the hypothalamus
Produces many hormones such as LH, FSH, oxytocin etc.
33
Describe the adrenal gland (roles, structure, hormone production etc.)
```
Located above the kidneys
2 main parts:
The outer (adrenal cortex)
The inner (adrenal medulla)
Hormones it secretes:
Cortisol - supports cardiovascular functions
Adrenaline - prepares fight or flight response
Noradrenaline - increases blood pressure
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34
Define gland
An organ in the human body that secretes chemical substances for use in the body
35
Outline 1 difference between the nervous system and the endocrine system
The nervous system uses electrical impulses whereas the endocrine system uses chemical messengers transported in blood
36
Where are neurotransmitters released from and absorbed?
Synaptic vesicles
| Post-synaptic receptor sites
37
What are neurotransmitters?
Chemicals which diffuse across the synapses to relay impulses to the next neurone
38
Give 6 physiological changes that adrenaline has on the body and their adaptive benefit
Increased heart rate - speed up blood flow to organs
Faster breathing - increase oxygen intake
Muscle tension - improve reaction time and speed
Pupil dilation - improve vision
Sweat produced - helps regulate temperature
Reduced digestive function - saves energy
39
What does adrenaline do?
Prepares fight or flight response
40
What does noradrenaline do?
Increases blood pressure
41
What is the fight or flight response caused by?
Stress/stressful situations
42
Explain the case of Phineas Gage
| Why was this important?
In 1848, he was working in a railway line with explosives. A metal pole went through his frontal lobe. His personality changed - he became quick tempered and rude.
This questioned the holistic theory of the brain.
43
What did Broca and Wernicke study?
How did they do this?
What did they find?
What did this enable them to do?
People with language problems.
By looking at their brains post-mortem, they found anatomical differences and damage.
This enabled them to identify specific brain areas associated with specific language functions.
44
Using an example, explain what is meant by localisation of function
The idea that certain areas of the brain can be linked with specific functions. This was suggested after the case of Phineas Gage, which questioned the holistic view. Damage to an area will affect the associated function.
45
The brain is divided into 2...
These are joined by the...
This is made up of...
Its function is to...
Hemispheres
Corpus callosum
Bundles of nerve fibres
Allow communication between the hemispheres of the brain
46
Define contralateral. Give an example.
| What is the opposite of contralateral? Define it.
When the function on one side of the body is controlled by the opposite hemisphere of the brain.
Eg: movement of the left hand is controlled by the right hemisphere.
Lateral. When a function is only dealt with by one hemisphere of the brain.
47
The cortex of the brain is like a tea cosy. Why?
It’s a thin layer 3mm thick covering inner parts of the brain. It looks grey and is more developed than in other animals.
48
How many lobes are in each hemisphere?
| List them and what their functions are
4.
Frontal lobe - abstract thinking, planning and social skills.
Parietal lobe - touch, spatial orientation, nonverbal thinking.
Temporal lobe - language, hearing and visual pattern recognition.
Occipital lobe - vision.
49
```
What lobes are the following in?
Broca’s area,
Motor cortex,
Somasensory cortex,
Auditory centres,
Wernicke’s area,
Primary visual cortex.
```
```
Frontal lobe,
Frontal lobe,
Parietal lobe.
Temporal lobe.
Temporal lobe.
Occipital lobe.
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50
What is the function of?
Broca’s area,
Wernicke’s area.
Speech production, and grammar.
| Speech comprehension.
51
Where is the motor cortex found?
| Explain its function
The back of the frontal lobe.
| Controls voluntary movement in the opposite side of the body. Damage may result in loss of control over fine movements.
52
Where is the somatosensory cortex found?
| Explain its function
The front of the parietal lobe.
It’s where sensory information from skin is represented. The amount of it devoted to a particular body part details its sensitivity.
Eg: receptors for face and hands occupy over half of it.
53
What separates the motor cortex and the somatosensory cortex?
A ‘valley’ called the central sulcus/central fissure.
54
Where are the visual centres found?
| Explain their function
Occipital lobe
Each eye sends information from the right visual field to the left visual cortex and from the left visual field to the right visual cortex. This means that damage to the left hemisphere for eg: can produce blindness is part of the right visual field of both eyes.
55
Where are the auditory centres found?
| Explain their function
Temporal lobe
Analyses speech-based information. Damage may produce partial hearing loss; the more expense the damage, the more extensive the loss. Also, damage to a specific area of the temporal lobe - Wernicke’s area - may affect the ability to comprehend language.
56
```
When was Broca’s area identified?
What is it linked to?
What is the condition called when this area is damaged?
What does this cause?
Give an example case study?
```
1880’s.
Speech production.
Broca’s aphasia.
Speech that is slow, laborious and lacking in frequency.
Tan. He was named Tan because his Broca’s damage meant “tan” was the only thing he could say.
57
How did Carl Wernicke discover his region?
What is damage to the Wernicke’s region called?
What does this cause?
He noted people who could produce speech but struggled to understand it. These people could produce fluent speech but it had no meaning.
Wernicke’s aphasia.
Patients will add nonsense words in with their speech.
58
Evaluate localisation of function in the brain
+ Phineas Gage case study was the foundation and allowed for more insight into the theory.
+ Peterson supports as he found proof of localisation through brain scanning the activity of the areas during a listening and reading task.
+ Tulving found that semantic and episodic memories are focused in different sides of the pre-frontal cortex. Summin about plasticity equipotential - application.
- Dronkers et al looked at Broca’s patients’ brains and found other areas’ lesions could impact speech disruption.
- Lashley (1950) removed areas of the cortex (10-50%) in rates who were trying to work out a maze. He found that no area of the cortex being removed was specifically important in completion or the task. The brain appears to process the task holistically. Yh but that’s rats.
- Dougherty et al (2002) looked at OCD patients with cingulotomy (lesioning of the angulate gyri). Post surgery follow up 32 weeks later: a third of patients met the criteria for successful surgery.
59
Define lateralisation
The concept that the 2 hemispheres of the brain have different functionality.
Some mental processes in the brain are mainly specified to one hemisphere of the brain - either the right or the left.
60
Define split-brain
Research where people have had their brain hemispheres separated by severing the corpus callosum
61
Define holistic with respect to the brain
The brain functions as one holistic mechanism and that the 2 hemispheres of the brain work together
62
Explain contralateral processing of visual information
In a typical brain, information from the left visual field is processed in the right hemisphere and information from the right visual field is processed in the left hemisphere.
63
What is the corpus callosum?
A bundle fibres that allows each hemisphere to “talk” to each other.
64
Explain Sperry’s split-brain research.
1968.
He aimed to show that the hemispheres of the brain had certain functions. He studied patients who had received an operation to cut their corpus callosum to control epileptic seizures. As a result, information from one hemisphere could not be communicated to the other for processing. This allowed researchers to assess the function of each hemisphere individually.
65
Outline the main aspects of Sperry’s procedure.
| Include detail on the participants.
Patients stare at a black dot and an image or word is projected to patients’ RVF or LVF for 0.1 seconds.
There were 11 participants and all had a history of epileptic seizures.
66
State and explain Sperry’s findings regarding what participants’ left and right visual fields did when objects were presented to either visual field
RVF - p’s could easily describe what was seen. This mean info from the R.V.F. is processed in the L.H. Because the language centres are also located in the L.H, P’s are able to make what they are shown.
LVF - participants would say they didn’t see anything. This means info from the L.V.F is processed in the R.H. They couldn’t say what they saw due to no language centres being there.
67
State and explain Sperry’s findings regarding what participants’ left visual field did when objects were touched but not visible
LVF - participants couldn’t name the objects but could also select an object associated with what the say eg: an ashtray if they saw a cigarette. This shows the the R.H. allowed the, to understand what the object was and to make choices based on meaning. They couldn’t name objects because there are no language centres in the R.H.
68
State and explain Sperry’s findings when participants were asked to match a face from several others, when shown to their left and right visual fields.
Pictures presented to the L.V.F. were consistently selected yet those presented to the R.V.F. were constantly ignored. This shows the R.H. appears to have a role in facial recognition. Images presented to the R.V.F. processed in the L.H. because patients didn’t acknowledge those faces; it may be that recognition doesn’t take place in the L.H.
69
Evaluate lateralisation of function in the brain and split-brain research
+ scientific breakthrough - it was controlled, and could access the brain. It provides an insight into both the brain and consciousness through research - application
+ methodology - highly specialised and standardised procedures. His procedure was very well-controlled and useful. Replicable, falsifiable - validity.
- plasticity - the brain can change after to damage to compensate. Language lateralisation changes with age.
- generalisability - there were only 11 participants in Sperry’s experiment. This may have caused unique changes in the brain that may have influenced the findings. Some participants had experienced more disconnection.
70
What is plasticity also known as?
Define it.
What are the brain changes a result of?
Neuroplasticity, cortical remapping.
The brain changes or adapts functionally and physically.
The brain changes as a result of experience and learning new stuff.
71
What is functional recovery?
What is it a form of?
Why does the brain change?
When the brain changes, redistributes or transfers functions from one area to another.
A form of plasticity.
The brain changes as a result of damage and trauma.
72
Explain what Gopnick et al did
A study on the connections in babies’ brains.
During infancy, the brain shows rapid growth in the number of synaptic connections. At age 2-3, the number of these peaks is at 15,000. This is twice as many as there are in the adult brain. This difference is the result of a process called synaptic pruning.
73
Define synaptic pruning
When synaptic connections that we don’t use very much are deleted, and those that we do use are made stronger.
74
State the 3 pieces of research that suggests neural connections can be changed or formed at any stage in life (evidence of plasticity)
Maguire et al (2000) - London taxi drivers
Draganski et al (2006) - medicinal students
Mechelli et al (2004) - bilingual brains
75
Explain Maguire et al’s evidence to show plasticity in the brain
London taxi drivers.
There was increased grey matter in the hippocampus compared to the control group. The more time spent in the job, the greater the structural difference.
76
Explain Draganski et al’s evidence to show plasticity in the brain
Medical students.
| Brain scans before and after final exams showed changes in the posterior hippocampus and parietal cortex
77
Explain Mechelli et al’s evidence to show plasticity in the brain
Bilingual brains.
| There was a larger parietal cortex in bilingual brains compared to people who can only speak one language.
78
Explain the difference between functional recovery and spontaneous recovery
Functional recovery refers to when unaffected areas of the brain adapt and compensate for damaged areas.
Spontaneous recovery is when there is quick recovery shortly after the trauma this can be slowed down after several weeks or months which is when rehabilitation may be required to help further recovery.
79
Explain what Doidge found
2007 - the unmasking of neural pathways.
Found that Secondary neural pathway is not typically used for the damaged function (dormant synapses) are activated or unmasked so that functioning can continue. This is supported by different structural changes in the brain.
80
What are the 3 structural changes in the brain during functional recovery that support the unmasking of neural pathways?
Axonal sprouting
Reformation of blood vessels
Recruitment of homologous areas
81
Explain axonal sprouting
New nerve endings grow and connect with other underaged nerve cells to form new neuronal pathways
82
Explain the reformation of blood vessels
Blood vessels reform to support other changes
83
Explain the recruitment of homologous areas
Similar areas in the opposite hemisphere of the brain carry out the functions of the damaged area e.g: if Broca’s area was damaged a similar area in the right hemisphere could be used to take over language production.
84
Evaluate plasticity and functional recovery
+ practical applications of research into neuroplasticity - neurorehabilitation. After brain illness/injury, the brains’ spontaneous recovery tends to slow down after a number of weeks, so forms of physical therapies may be required. Techniques include movement therapy and electrical stimulation to counter deficits in motor/cognitive functioning that may be experienced eg: after a stroke. Shows the brain has the capacity to fix itself to a point, but further help required.
- plasticity can have negative consequences - possible maladaptive behavioural consequences eg: prolonged drug use results in poorer cognitive functioning and risk of dementia when older. 60-80% amputees have phantom limb syndrome. Usually unpleasant, painful and are thought to be due to cortical reorganisation in the somatosensory cortex that occurs as a result of limb loss.
- explanations need to account for I.D. eg: age - F.P. tends to reduce with age. The brain has a greater propensity for reorganisation in childhood due to new experiences and learning. Bezzola et al’s experiment...
+ support from animal studies - early evidence from Huber and Wiesel...
85
Explain Bezzola et al’s experiment on golf in relation to individual differences in plasticity and functional recovery
They demonstrated how 40 hours of golf training produced changes in the neural representation of movement in participants aged 40-60. Using fMRI, the researchers observed reduced motor cortex activity in novice golfers compared to a control groups suggesting more efficient neural representations after training. This hows neural plasticity continues throughout our lifespan.
86
Explain Hubel and Wiesel’s study as support from animal studies for plasticity and functional recovery.
They sewed a kitten’s eye shit and analysed the brains’ cortical responses. The visual cortex area associated with the shut eye wasn’t idle (as had been predicted) but continued to process information from the open eye.
87
What are the 4 ways of investigating the brain?
fMRI
EEG
ERP
Post mortem examinations
88
Explain what fMRI’s are and do
Functional Magnetic Resonance Imaging works by detecting the changes in blood oxygenation and flow that occur as a result of brain activity in specific parts of the brain. More active areas consume more oxygen and has a greater blood flow (the haemodynamic response). It creates 3D images (activation maps), showing which parts of the brain are involved in specific mental processes. This helps understanding of localisation of function.
89
Explain what EEG’s are and do
Electroencephalograms measure electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a skull cap. The scan represents brainwave patterns that are generated from the action of millions of neurons, providing an overall account of brain activity. It’s often used by clinicians as a diagnostic tool as unusual arrhythmic patterns of activity may indicate neurological abnormalities such as epilepsy, tumours or disorders of sleep.
90
Explain what ERP’s are and do
Event Related Potentials are types of brainwaves that are triggered by particular events. This data contains all the neural responses associated with specific sensory, cognitive and motor events. Researchers can ‘tease out‘ these responses by using a statistical averaging technique, all extraneous brain activity from the EEG is filtered out leaving the responses that relate to xyz. Research has revealed many different forms of ERP.
91
Explain what Post Mortem Examinations are and do
They are a technique involving the analysis of a dead brain. In psychological research, those who have this usually have a rare disorder and have experienced unusual deficits in mental processes or behaviour during their lifetime. This establishes the likely cause of the affliction the person suffered. This may also involve comparison with a neuro typical brain in order to ascertain the extent of the difference.
92
Evaluate fMRI’s
+ no radiation, virtually risk-free, non-invasive and straightforward to use. High spatial resolution in images which provide a clear picture of how brain activity is localised. Can produce information about the brain relating to a specific task being carried out. Images can show more than one part of the brain active at one time. Can show localisation of brain function.
- expensive compared to other neuroimaging techniques and can only capture a clear image if the person is completely still. Not portable equipment. It can only measure blood flow in the brain, not the activity of individual neurones, so it can be difficult to exactly what kind of brain activity is being represented on screen. 5 second time lag - shit temporal validity.
93
Evaluate post mortem examinations
+ Broca and Wernicke both relied on these studies for establishing links between language, brain and behaviour decades before neuroimaging existed. They improve medical knowledge and help generate hypotheses for further study. Allows investigation of areas deep in the brain as well as neurochemistry in the brain. Can show localisation of brain function.
- causation. Observed damage may not be linked to the deficits reviewed. Other decay trauma can be unrelated. Ethical issues regarding informed consent from family. Limited sample size - dead people.
94
Evaluate EEG’s
+ proved invaluable in the diagnosis of conditions such as epilepsy and it also helped understand sleep. Non-invasive.
- not useful for pinpointing the exact source of neural activity as reading produced come from many neurons so are general. It doesn’t allow researchers to distinguish between activities originating in different but adjacent locations. Electrodes attaches to scalp can only give readings from the brain cortex, not deeper areas of the brain.
95
Evaluate ERP’s
+ bring more specificity to measuring neural processes than could ever be achieved using raw EEG data. Non-invasive. Can produce information about the brain relating to a specific task being carried out. Uses statistical averaging to add detail to EEG recording.
- lack of standardisation in ERP methodology between research studies - this makes it difficult to confirm findings. Electrodes attaches to scalp can only give readings from the brain cortex, not deeper areas of the brain. Research faces difficulties because researchers may use different statistical analysis which prevents comparisons to be made and conclusions to be drawn.
96
What is a biological rhythm?
A cycle of activity that occurs with some regularity in a living organism.
97
Give examples of some biological rhythms
Menstrual cycle, sleep/wake cycle, temperature
98
What are biological rhythms governed by?
Both internal biological clocks and environmental cues
99
What is an endogenous pacemaker?
| What is an exogenous zeitgeber?
Internal, biological clock.
| External, environmental clock.
100
What are the 3 types of biological rhythm?
How often do they occur?
Give examples for each
Infradian - less than 1 in 24 hours - menstrual cycle, SAD.
Circadian - every 24 hours - core body temp, sleep/wake cycle.
Ultradian - more than 1 in 24 hours - stages of sleep, basic rest-activity cycle.
101
Why is light important?
It’s an exogenous zeitgeber that helps to guide when we feel drowsy and sleep, and when we wake and are more alert.
102
What are the 3 light-deprivation studies?
| What is the aim of these studies?
Siffre cave studies
Aschoff and Weaver (1976) bunker study
Folkard et al (1985) cave study with speeded up clock
To assess the role of a person’s internal biological clock (endogenous pacemaker)
103
Explain the Siffre cave studies
These were several cave studies with no normal light or external sound. He learnt that his ‘free running’ rhythm was around 25 hours. He spent 2-6 months underground, a decade apart. He still had a regular sleep/wake cycle. This suggests that clocks and external zeitgebers may ‘entrain’ sleep/wake to 24 hours.
104
Explain Aschoff and Weaver’s bunker study
1976
Group of participants spent 4 weeks in a bunker with no natural light. Most participants’ rhythms were between 24 and 25 hours. One participant’s cycle extended to 29 hours. This suggests clocks and external zeitgebers may ‘entrain’ sleep/wake cycle to 24 hours.
105
Explain Folkard et al’s cave study with speeded up clock
1985
12 people lived in a cave for 12 weeks, going to bed when the clock said 11:45 and waking at 7:45. Researchers gradually sped up the clock so that in the end a day was only 22 hours long. Only one person comfortably adjusted to this.
106
When is the core body temperature:
At its highest?
At its lowest?
Why is this?
6pm
4am
There may be a link to cognitive ability - we may perform when we are warm.
107
Evaluate circadian rhythms
Practical applications: drug therapy. Circadian rhythms coordinate a number of the body’s basic processes such as heart rate, digestion and hormone levels. Circadian rhythm research has shown there are certain peak times during the day or night when drugs are most likely to be effective. This led to development of guidelines to do with timing of drug dosing for anti cancer, cardiovascular respiration, anti-ulcer and anti-epileptic drugs (Baraldo - 2008).
Shift work. Boivin et al (1996) found a circadian trough - a period of reduced concentration around 6am meaning mistakes and accidents are more likely. Knutsson (2003) found that shift workers are 3 times more likely to develop heart disease - this may in part be due to the stress of adjusting to different sleep/wake patterns and the lack of poor quality sleep during the day. This work has economic implications because research into the sleep/wake cycle may have economic implications in terms of how best to manage worked productivity.
- methodological problems. Siffre was not isolated from artificial light, which a study found could alter people’s rhythms from 22 hours to 28 hours.
- I.D. - Siffre was one guy. Czeisler found that C.R’s. can range from 13-65 hours. Duffy found a difference between lark and owl people.
108
What are pharmacokinetics?
The actions of drugs on the body and how well they are absorbed and distributed.
109
Define desynchronisation
The adverse consequences that can occur as a result of circadian rhythms disruption.
110
Explain one useful application that has come from age differences in circadian rhythms
Duffy et al. revealed that some people display a natural preference for larks or owls. They are also age differences in sleep/wake patterns. A pilot study led by Dr Kelley in North Tyneside found that starting school at 10am increased grades and positivity. This is because teenagers’ circadian rhythm is allegedly 2 hours behind.
111
What are the 2 ultradian rhythms you need to know?
| What are the 2 infradian rhythms you need to know?
Stages of sleep, BRAC.
| The menstrual cycle, SAD.
112
How are stages of sleep measured?
How long is a sleep cycle?
How many do we have a night?
Using an EEG
Approx 90 minutes
Around 5 cycles a night
113
Explain stages 1 and 2 of sleep
Light sleep, easy to wake, at the beginning of sleeping, brainwave patterns start to get slower and more rhythmic (alpha waves), becoming even slower as sleep becomes deeper (theta waves).
Stage 1 - theta waves. Stage 2 - light sleep.
Can experience hypnogogic dreams shortly after drifting off, may experience feeling being out of control or falling. These dreams are significant for the fact we often wake with a jolt (a hypnic twitch) when we’re about to hit the ground.
114
Explain stages 3 and 4 of sleep
Both delta waves.
Slow waves with greater amplitude than earlier waves, this is deep sleep/slow wave sleep. It is difficult to rouse someone.
No dreams.
115
Explain stage 5 of sleep
REM sleep - Rapid Eye Movement - denotes the fast, jerk activity of eyes under eyelids.
The body is paralysed yet brain activity speeds up significantly in a manner that resembles the awake brain.
Research has shown REM activity is highly correlated with dreaming.
116
What does BRAC stand for?
Who argued this? What did they argue?
What is this characterised by?
Give 2 examples.
The Basic Rest-Activity Cycle.
Kleitman (1969) argued that there is a 90 minute cycle when we are awake. This is characterised by a period of feeling alert followed by a time of psychological fatigue.
Eg: the frequent observation that students struggle to concentrate for more than 90 minutes at a time. Similarly, coffee breaks at work.
Ericsson et al (1993) found that the best violinist tended to practice for 3 sessions during the course of the day, each session lasted no more than 90 minutes, and there was a break between each to ‘recharge’.
117
How many days are in the average menstrual cycle?
| Explain the key hormones in the menstrual cycle and what they do.
28 days.
Rising levels of oestrogen lead the ovary to develop an egg and release it at ovulation. After ovulation, the hormone progesterone helps the womb lining thicken in preparation for possible pregnancy. If there is no pregnancy, the egg will be absorbed and menstruation begins.
118
Explain the 4 key stages of the menstrual cycle.
| State the days as to when each occurs.
Day 1 - menstruation.
Day 14 - the egg is released from the ovary, the uterus lining builds up.
Day 21 - the lining is maintained.
Day 28 - if no pregnancy, the lining begins to breakdown (menstruation begins).
119
```
Explain McClintock’s study. Include:
Participants,
Technique,
Findings.
What does this show about the relationship between exogenous zeitgebers and endogenous pacemakers?
```
1998 - synchronising menstrual cycles using pheromones.
There were 29 women with a history of irregular periods.
Pheromone samples were taken from nine women at different stages of their menstrual cycles via a cotton pad placed in their armpit. They were worn for at least eight hours to ensure pheromones were collected. The pads were then treated with alcohol and frozen. They were them dabbed onto the top lips of the other women.
68% of women experienced changes to their cycle which brought them closure to their ‘odour donor’.
120
What does SAD stand for?
What was it diagnosed as?
List some symptoms.
Seasonal Affective Disorder.
Diagnosed as a mental disorder in DSM-5.
Persistent low mood, general lack of activity and interest in life.
121
What is a circannual rhythm?
A yearly cycle - a type of infradian rhythm.
It can also be classed as circadian as it may be due to the disruption of the sleep/wake cycle and this can be attributed to prolonged periods of daily darkness during winter.
122
Explain what the exogenous zeitgeber and the biological pacemaker are for SAD.
How do they interact to lead to symptoms of depression?
E.Z: lack of sunlight hours.
B.P: melatonin - a hormone. During the night, the pineal gland secretes melatonin until dawn where there’s more light.
The lack of light means melatonin secretes for longer. This is thought to have a knock on effect on the production of serotonin in the brain.
123
Evaluate ultradian and circadian rhythms
+ research on bodily rhythms supports the idea that exogenous zeitgebers and endogenous pacemakers interact - eg: menstrual synchronisation, looking at amount of daylight hours in relation to mood. Application - understand and treatment of SAD, helping people with sleep disorders, through melatonin use and light cues, timetabling of academic activities with 90 minute BRAC in mind.
+ research supports ultradian rhythms and stages of sleep’s existence. Dement and Kleitman study.
- methodological issues in menstrual synchronisation study. Confounding variables eg: stress, diet, exercise. This means everything could have happened by chance. Small sample can’t be generalised, objectivity, experimenter bias.
+ phototherapy works by a light box that simulates very strong light in the morning and evening. It is thought to rest melatonin levels in people with SAD. Eastman (1988) showed that it relieves symptoms by up to 60% of sufferers.
124
Explain Dement and Kleitman’s experiment
They monitored sleep patterns or 9 adults in a sleep lab. Brain wave activity was recorded on an EEG and the researchers controlled alcohol and caffeine effects. REM activity highly correlated with how vivid dreams were and participants woken during sleep reported very accurate dream recall.
Using EEG as a measure of stages of sleep is beneficial because replications notes similar findings. This increased the reliability of this research.
125
State 2 endogenous pacemakers
SCN
| Pineal gland
126
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What does SCN stand for?
What is it considered?
Where is it found?
What is its main function?
What does it use?
What information does it send and where?
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Suprachiasmatic nucleus.
The master clock.
Hypothalamus.
To regulate circadian rhythms.
It uses information about ambient light and levels of melatonin to help it work out the time of day.
It send information about levels of light to the pineal gland.
127
What does the pineal gland secrete?
What does it look like?
What are the highest and lowest levels of this hormone?
What is it known as?
Melatonin
Shaped like a pine cone
Highest in the middle of the night, lowest in daylight hours
Known for its role in regulating circadian rhythms
128
Explain the 2 experiments that are evidence for the importance of endogenous pacemakers. Include the method and findings for both.
Research that shows the role of the SCN in establishing and maintaining the circadian sleep/wake cycle:
Decoursey et al (2000) - destroyed SCN connections in 30 chipmunks, returned them to the wild and observed them for 30 days. Many were killed by predators because without circadian rhythms, they were awake at the wrong time.
Ralph et al (1990) - bred ‘mutant’ hamsters with a 20 hr cycle and then transplanted foetal SCN cells into the brains of normal hamsters. Previously normal hamsters now showed a 20hr cycle as well. This supports the SCN as an endogenous pacemaker.
129
Explain the 2 experiments that are evidence for the importance of exogenous zeitgebers. Include the method and findings for both.
Campbell and Murphy (1998) shone light in the back of knees of participants woken several times in the night. Some cycles changed by up to 3 hours. This shows light is an important zeitgeber, but doesn’t have to go through the eyes - skin appears to be a receptor too.
The potential role of social cues:
Parenting - imposing meal times and bed times to entrain the circadian rhythm.
Jet lag - by using zeitgebers of the country you have travelled to, you can adjust your cycle so that it is synchronised to the new time zone. Eg: when the locals eat, leave curtains open when you sleep so that the light (zeitgeber) can help entrain your circadian rhythm to the new time zone.
130
Evaluate endogenous pacemakers and exogenous zeitgebers
+ using animals - less ethical issues than human testing.
- there are still ethical issues.
- peripheral oscillators research - Damiola et al (2000) changes feeding patterns in mice. This altered the circadian rhythms of their liver cells by up to 12 hours yet their SCN wasn’t affected. There’s the SCN isn’t the only controller of circadian rhythms. Even if the SCN is the master clock, other influences are at play. Explanations lack validity as they can’t explain what all of these factors are.
- pacemakers and zeitgebers cannot be separated and will always interact. Studies like Siffre attempt to isolate zeitgebers, but they don’t reflect real life where endogenous pacemakers and exogenous zeitgebers always interact. Many examples of research are therefore limited because they don’t explain the interaction so they lack validity.
131
Give examples of peripheral oscillators
Adrenal gland, oesophagus, lungs, liver, pancreas, spleen, thymus and skin
