Biopsychology Flashcards
(140 cards)
1
Q
Describe the motor cortex
A
Controls the muscles via the spinal cord
In the front lobe of both hemispheres
Different parts control specific areas of body
Cortex on right side controls left side
Cortex on left side controls right side
2
Q
Describe the Broca’s area
A
One of the language areas involved in speech production.
It is situated on the left hemisphere (in most people) close to the motor cortex that controls the mouth
3
Q
Describe the auditory centres of the brain
A
Located in the temporal lobes on both sides of the Brain
Information from the ears is processed in different areas of the brain but ends up in the auditory cortex where it is recognised and responded too
4
Q
Describe the wernicke’s area of the brain
A
Another language centre
Involved in language comprehension and anomia
Situated near the junction of the left temporal and partial lobes
5
Q
What is wernicke’s aphasia
A
Difficulty understanding language may speak nonsense or make up words
6
Q
How is the Broca’s area and the wernicke’s area connected
A
Neural loop
7
Q
Describe the visual centre of the brain
A
Many areas in brain involved in processing visual info
This is the main area for detecting patterns and processing info about moving objects
Visual cortex in the occipital lobe
8
Q
What may occur if there is damage to the visual cortex of the brain
A
Damage to left may mean individual is blind in right field of vision
Vice verca
9
Q
Describe the somatosensory cortex
A
Responsible for the sensation of touch
Distributed across the parietal lobes and receives information from opposite side of body to lobe
More areas in the cortex is given over to areas of the body with a lot of sensory receptors such as fingers and lips
(In both hemispheres)
10
Q
What is a strength of localisation of function of the brain
A
Supporting evidence
Development of brain scanning techniques such as fMRI providing objective scientific evidence for idea that different areas of brain perform different functions
One study of Broca’s area was active when reading out loud
Another study found semantic memories are associated with pre-frontal cortex whereas episodic memories are associated with the left pre frontal cortex ( tulving et al)
Findings support for localisation of function
11
Q
What is a weakness of localisation of the brain
A
Challenging evidence
Research shows functions such as learning does not appeared to be linked to specific area, processed in many
One study investigated impact of learning a maze on rats who each had different parts of their cortex removed
No brain area was found more important for learning than others
Also found learning involved numerous parts of the cortex rather than localised areas
Suggests some processes require all parts of brain not specific regions
12
Q
What is localisation of function in the brain
A
The idea that different part of the brain are responsible for particular skills and abilities (functions)
13
Q
What is the outer layer of the brain called
A
The cerebral cortex
14
Q
How many hemispheres are in the cerebral cortex
A
2
Left and Right
15
Q
How are the two hemispheres of the brain connected
A
Via the corpus callosum
16
Q
What is plasticity
A
The brains ability to adapt its structure and the way it processes information
E.g if the left motor cortex becomes damaged the right motor cortex can take over
17
Q
What are two examples of plasticity
A
Pruning
Bridging
18
Q
What is pruning
A
When brain connections are lost due to lack of use
19
Q
What is bridging
A
Where new connections are created due to use and stimulus
20
Q
Who studied plasticity using taxi drivers
A
Maguire et al
21
Q
Explain maguires research into plasticity
A
Studied brains of London taxi drivers, specifically the hippocampus
Used matched pairs to study 16 healthy taxi drivers, the control group was the same age matched on health non taxi drivers
Found London taxi drivers had more neuron cell body’s in their right and left posterior hippocampus than participates in the control
A positive correlation was found
22
Q
What is a strength of localisation of function of the brain
A
Development of brain scanning - fMRI provides objective, scientific supporting evidence for idea different brain areas perform different functions
One study found Broca’s area active when reading out loud.
Another study found memories associated with right pre-frontal cortex
Findings support localisation of function
23
Q
What are the weaknesses of localisation of function of the brain
A
There is challenging evidence - some research has shown that functions like learning are not appeared to link to specific brain locations - processed by many
One study investigated rats learning a maze who each had different part of cortex removed - no brain area found more important than others
Also found learning involved numerous parts of cortex - suggests some processes require all parts of brain not specific regions
Further evidence - challenged idea of localisation of function comes from research into plasticity.
People with brain damage and lose specific cognitive functions are sometimes able to functionally recover these abilities as brain reorganised itself
This suggests specific functions not confined to specific areas but other parts of the brain are able to fulfil lost function when needed.
This would suggest that the brain operates on a holistic (overall) rather than localised basis
24
Q
What is hemispheric lateralisation
A
This means that some functions of the brain are controlled by one hemisphere and not the other
25
What is the role of the left hemisphere
Responsible for speech and language
More active processing fine details
Logical and mathematical
26
What may be the outcome if a person has a stroke effecting the left hemisphere of the brain
Their ability to speak may be affected.
This is because Broca’s and Wernicke’s area are located exclusively in the left hemisphere
27
What is the right hemisphere of the brain responsible for
Visual and spatial processing
Processing the ‘bigger picture’
Recognising emotions and faces
28
What is an example of the left hemisphere processing fine detail
When looking at a picture, the left side of the brain will process the small intricate details
29
What is an example of the right hemisphere involving visual and spatial processes
A case study of a women with right hemisphere damage found she quickly became lost even in familiar settings unless she had verbal instructions with visual cues such as ‘turn right at the post box’
30
What is an example of the right hemisphere processing the bigger picture
When looking at a picture the right is active when looking at its whole, suggesting overall patterns
31
What is an example of the right hemisphere of the brain processing emotions and recognising faces
A study found when people were shown a split fave where one was half smiling one was neutral. The emotion indicated by the left side of the face was the one reported most often
The left visual field is processed by the right hemisphere
32
What happens if the visual centre is damaged
Damage to the left hemisphere - right eye may go blind
Damage to right hemisphere - left eye might go blind
33
What happens if the Broca’s area is damaged
People often suffer from Broca’s aphasia
Producing speech requires great effort, is slow and laboured
Speech lacks fluency in that words that help sentences function ‘it’ or ‘the’ are often missing
May be produce meaningful sentences but ones containing few words
34
What happens if the wernicke’s area is damaged
People who damage this suffer from wernicke’s aphasia
They can produce language and speak fluently
They have difficulty understanding languages so they often say nonsense or make words up
35
What happens if there is damage to the motor centres of the brain
There will be an issue with movement
36
What happens if you damage the somatosensory centre
You may have issues with pain tolerance it may be higher or lower
37
What happens if you damage the auditory centre
Potential hearing problems
38
What is a strength of hemispheric lateralisation?
There is an advantage of using lateralisation
It is often assumed whilst one hemisphere is occupied with a task the other is free to deal with another process so we can increase our capacity to process information
Eg we can process a language and spatial task at the same time.
One study in chickens found brain lateralisation enabled a chicken to forage for food and remain vigilant for predators
This suggests the idea of lateralisation seeks to be an effective way to process information and utilise brain capacity’s
39
What are weaknesses of research into hemispheric lateralisation
Challenging evidence
Turk et al - patient who suffered damage to left hemisphere developed capacity to speak using right hemisphere eventually leading to ability to speak about information presented to either hemisphere.
Suggests lateralisation of function is not a fixed characteristic of the brain and it can adapt following damage.
Weakness of research - loose confidence due to counter evidence question validity of research conducted
Challenging evidence - researched found language became more lateralised to left hemisphere with increasing age but after 25 lateralisation decreased each decade.
Suggests lateralisation changes / implies lateralised brain is only a feature of young children and adults - not true beyond adulthood
Weakness - question validity of original research due to counter evidence
40
Why was split brain surgery orgininally conducted
To treat patients with severe epilepsy
41
Describe what a split brain is
Surgery to remove the corpus callosum that connects two hemispheres - prevents each hemisphere communicating with the other
42
Who conducted research into split brains
Sperry et al
43
Explain the procedure of research into split brains
Sperry et al
Split brain individual would fixate on a dot in centre of screen while info briefly presented to right or left visual field or both
Patient asked to describe what was seen or select object that was presented on screen with left or right hand (objects behind a screen)
Words shown to right visual field were easily described because images presented to right side are processed in left hemisphere where the language centres are based .
Words shown to left visual field could not be described, however they could draw the word or pick up an item associated with the word.
Two words that represent an object E.g key and ring presented but participants could only pick up a key with left hand and recall word ‘ring’ as was processed by left hemisphere
44
In split brain research, what field of vision could participants see and recall
Word shown on right visual field could be described as this goes to left hemisphere where the language centres are
45
What had split brain research taught us
Left hemisphere is responsible for speech and language
Right hemisphere specialises in visual-spatial processing and facial recognition
Sperry concluded right hemisphere is capable of very basic language processing (recognising language) but more complex language tasks (speaking)
Split brain research not shown brain organisation in specific regions just that connectivity between regions is very important as the operation for different parts
46
Strengths of split brain research
Supporting evidence
Research indicates left hemisphere in charge of language and speech and right involved in visual and spatial processing as well as face recognition
Also evident two hemispheres need to communicate and contribute own processes to be successful overall functioning
Strength - research has strong evidence showing importance of corpus callosum and clear indication of hemispheric processing
47
Weaknesses of split brain research
Methodological issues
Split brain - rare procedure so few patients to be studied
Sperry’s research used 11 participants (small sample size) took part in all variations of study.
Low ecological validity as hard to generalise confidently regarding brain functioning from small sample size.
Split brain procedures also carried out on individuals with serious brain functioning problems that necessitated such surgery.
Weakness - we cannot confidently assume their responses after surgery are result only of two hemispheres being separated.
Challenging evidence
Gazzangia argued right hemisphere is able to handle language better than Sperry assumed
One patient (JW) developed capacity to speak using right hemisphere
Suggests language may not be exclusively limited to left hemisphere
Supports idea of brain plasticity as before surgery JW processed language in left hemisphere.
Weakness - shows brain can recover functions after physical trauma, loose confidence in accuracy of findings of Sperry’s research
48
What part of the brain is the motor cortex in
Very back of Frontal lobe, both hemispheres
49
What is the outer layer of the brain called
Cerebral cortex
50
Where is the somatosensory cortex
Behind motor cortex in parietal lobe, both hemispheres
51
Where is the visual cortex
Occipital lobe, both hemispheres
52
Where is the auditory cortex
Temporal lobe, both hemispheres
53
Who conducted challenging evidence for hemispheric lateralisation briefly what was it
Turk et al - patient could speak using right hemisphere
54
Who conducted challenging research to Sperry’s split brains
Gazzaniga
55
What was the name of the patient used in the split brain challenging evidence
JW
56
What is plasticity
Refers to the brains ability to change and adapt its structure and the way it processes information
57
What are two examples of plasticity
Pruning - where connections are lost due to lack of use
Bridging - where new connections are created due to use and stimulus
58
Explain a study into plasticity through learning and experiences
Maguire et al
To investigate how learning influences the hippocampus
Studied brains of London taxi drivers.
Natural experiment using matched pairs design of men with average age of 44, all with minimum 18 months job experience.
Control group had non taxi driver males matched for health, handedness and age
Found taxi drivers had more neuron cell bodies in their right and left posterior hippocampi than control group.
Positive correlation found between time spent as a taxi driver and volume of grey matter in right posterior hippocampus
59
What where the findings of Maguire et al plasticity study?
Taxi drivers had more grey matter (neuron cell bodies) in right and left posterior hippocampi then participants in control group
60
Evaluate Maguire research into plasticity
Psychologists argue it’s flawed
Taxi drivers not tested before they became taxi drivers so change of brain structure can not be concluded
Cause and effect can not be established - more research is required
Methods of measurement ehete objective and well controlled since measurements taken by a computer.
Study promotes healthy brain can change in response to learning. Implications after brain injury although only if it’s damage in hippocampal region as study is biologically reductionist
61
What is functional recovery
A demonstration of the plasticity of the brain.
The regaining of an ability that was lost following brain trauma
62
What is the process of functional recovery
If the brain becomes damaged after trauma structural changes can occur to regain sone of the function. This happens through neuronal unmasking and neural reorganisation
63
Explain the two processes of functional recovery
Neuronal unmasking is the process involving activating synapses that are inactive or unused. These are known as dormant synapses. When the brain is damaged the flow of neural impulses becomes diverted through nearby dormant synapses causing neural pathways to be created. This allows undamaged regions of the brain to take up the functions previously carried out by damaged areas.
Neural organisation is another example when a similar area of the brain on the opposite side takes over specific tasks. Eg Broca’s area was damaged, equivalent area in right hemisphere would take over its functions
64
Evaluate research into functional recovery
Supporting evidence
Gabby Gifford shot in the head and critically injured, comatised to survive. She made progress and rehabilitated, learnt to walk and write with her left hand. She learnt to read and speak in short phrases. This demonstrates the ability of the brain to create new connections using neurons manufactured by stem cells.
Alpha bias, research women being able to recover better than men as women’s brains are more lateralised. Study of 325 people who rehabilitated brain trauma were assessed and women performed better on tests over all. Emphasising the differences could lead to differences being ignored which could have a dramatic impact on negative recovery
65
What does fMRI stand for
Functional magnetic resonance imaging
66
What does EEG stand for
Electroencephalogram
67
What does ERP stand for
Event related potentials
68
What does PM stand for
Post mortem
69
What are the ways of studying the brain
FMRI
ERP
EEG
PM
70
How does functional magnetic resonance imaging work
Measures blood flow when individual does a task
Neurons in brain most active during the task will use up most oxygen.
Oxygen carried into blood stream attached to haemoglobin in red blood cells.
Once oxygen is used, haemoglobin becomes deoxygenated
Deoxygenated haemoglobin has different magnetic quality from oxygenated which is detected by fMRI and a dynamic 3D map of brain highlights areas used.
Increase in blood flow is a response to need for more oxygen in area when active suggesting increase in neural activity
71
When might fMRI scans be used in psychology
Participant asked to view images such as faces or objects whilst in MRI scanner to identify active parts of brain
72
How is an electroencephalogram used to scan brain
Works on premise information is processed in brain as electrical activity in form of action potentials or nerve impulses transmitted along neurons. EEF measures electrical activity through electrodes to the scalp, small charges are graphed.
Four patterns are made either alpha, beta, theta and delta.
73
What types of waves are detected in EEG
Alpha Bets Theta Delta
74
Where will EEG be used in psychology
To detect illnesses like epilepsy and sleep disorders. To diagnose other brain disorders like Alzheimer’s
EEG was used to understand REM
75
Explain how event related potentials are used to scan brain
Electrodes attached to scalp and stimulus presented to participant, researcher looks for activity related to stimulus. This is repeated and average graph is made.
Time between intervals I’d known as latency, ERP’s have a short latency of 100mliseconds
76
Where might ERP be used in psychology
Reactions to naked images of males or females showed both genders had stronger feelings towards opposite gender
77
Explain post mortem as a way of studying the brain
Used to investigate brain structure after death in individuals who showed unusual behaviour through life, to see if brain had abnormalities whilst alive.
Enables us to explore deep regions like hippocampus and hypothalamus
78
Where is post mortem used in psychology
Broca carried out a post mortem on a patient who could only say one syllable ‘tan’ and found he had damage in area known as the Broca’s area which is involved in speech production
79
What is spatial resolution
Refers to the smallest feature that a scanner can detect and is an important feature of scanning. Greater resolution allows psychologists to discriminate between different brain regions with greater accuracy
80
What is fMRI spatial resolution like
fMRI have good resolution of approximately 1-2mm which is significantly greater than other techniques.
Psychologists determine the activity of different brain regions with greater accuracy when using fMRI in comparison to when using EEG or ERP
81
What are the two nervous systems
Central nervous system
Peripheral nervous system
82
What is the central nervous system responsible for
Brain and spinal cord.
Responsible for controlling physiological processes such as breathing, heart rate and receiving information about the environment through the senses. Also controlling and initiating behaviour so has to be able to receive and transmit info to all body parts
83
Explain the role of the brain in the central nervous system
The information processor, oversees the running of the body and the coordination of behaviour as well as giving us conscious awareness.
Cerebrum - lagest part which is divided into two hemispheres which communicate via the corpus callosum
Cerebellum - at the back of the cerebrum, associated with motor skills and balance. Coordinates muscles and enables us to make very precise controlled movements
Brain stem - connects spinal cord to rest of the brain and motor and sensory neurons. Transmit info through brain stem to brain. Responsible for automatic functions of body such as breathing
84
Describe the cerebrum
Cerebrum - lagest part which is divided into two hemispheres which communicate via the corpus callosum
85
Describe the cerebellum
Located at the back of cerebrum and associated with motor skills and balance. Coordinates the muscles and enables us to make precise controlled movements. Abnormalities can affect us in a number of ways including movement problems and epilepsy
86
Describe the brain stem
Connects the spinal cord to the rest of the brain and motor and sensory neurons. Transmits info through brain stem to the brain. Responsible for regulating the automatic functions of the body such as breathing
87
Describe the function of the spinal cord in the CNS
To transmit information between the brain and rest of the body. Allows the brain to respond to incoming information so it can control and regulate body activity.
Spinal nerves branch off spinal cord to connect with different organs, muscles and glands. If the spinal cord is damaged no information can be relayed to and from the parts below the area of damage.
Spinal cord enabled some reflex actions such as pulling your hand away from a hot surface
88
What is an example of a reflex action your spine can perform
Pulling your hand away from a hot surface
89
Explain the peripheral nervous system
Made up of the autonomic and somatic nervous system. Responsible for communicating between the CNS and areas outside the peripheral to the brain such as limbs
90
Describe the somatic nervous system
Part of the peripheral nervous system that communicates with outside world. Communicates with muscles and gets sensory information from the skin.
Made up of 12 cranial nerves and 31 spinal nerves that emerge directly from the underside of the brain and spinal nerves. The nerves have motor and sensory neurons.
Sensory neurons send message to CNS and motor neurons send info from CNS to body part. Somatic nervous system deals with reflex actions that do not involve the brain
E.g tapping the knee
91
What nerves make up the somatic nervous system
12 cranial nerves
31 spinal nerves
92
What neurons are involved in the somatic nervous system
Sensory neurons send info to CNS
Motor neurons send info from CNS to parts of the body
93
Describe the autonomic nervous system
Peripheral nervous system
Controls unconscious bodily processes such as regulating heart beat and digestion. Affects the body’s threat to danger and initiated stress response. Divided into two sympathetic nervous system and parasympathetic nervous system.
Sympathetic - activating and stimulating effects
Parasympathetic- inhibiting effects
94
Describe the sympathetic nervous system
From the autonomic branch of the peripheral nervous system.
Brings about ‘fight or flight’ by increasing heart rate and bloody pressure and dialating blood vessels in muscles so more blood can get to them. Neurons from sympathetic nervous system communicate with almost every gland or organ.
95
Describe the parasympathetic nervous system
Autonomic branch of peripheral nervous system. Counter acts the sympathetic nervous system.
Once crisis has passed heart rate and blood pressure reduces.
Rest and digest
96
Describe a neuron
A nerve cell that is highly specialised to communicate information around the nervous system.
They have a large cell body which contains the nucleus (the control centre of the neuron)
Dendrites are long thin branches that protrude from the cell body. They receive information from neighbouring neurons and transport messages towards the cell body.
The axon id a large branch that carries info away from the cell body, there are small terminals at the end of the axon which communicate with the next neuron across the synapse.
The axon is encased in a fatty layer called the myelin sheath which protects the axon as well as enabling nerve impulses to travel quicker.
97
What are the 3 different neurons
Sensory
Motor
Relay
98
Describe the function of the sensory neurons
Carry information from sensory receptors (touch, sound, vision, taste) to the CNS.
Sensory neuron converts info from sensory receptors into neural impulses that are decoded in the brain to produce appropriate sensation to allow us to react appropriately. Some sensory info is dealt with in spinal cord and does not travel to brain to enable reflex actions to take place quickly.
Sensory neurons have long dendrites and short axons
99
Describe the function of relay neurons
Most common neurons. Communicate between motor and sensory neurons.
Exist only within the brain and spinal cord.
Have short dendrites and short axons
100
Describe the function of motor neurons
Within the CNS project their axons out of the CNS to directly or indirectly control muscles. Influence contraction of muscles. When axon is activated it produces contraction of the muscle, when inhibited produces muscle relaxation.
Short dendrites and long axons
101
What is the overall function of a neuron
To transmit information within a neuron by electrical impulses and between neurons chemically by neurotransmitters
102
Describe the transmission of information within a neuron
Info travels among a neuron by an electrical impulse based upon an accruing potential. When the neuron becomes positively charged compared to the outside it causes an electrical impulse to travel down the axon towards the end of the neuron. (Pre-synaptic transmission)
103
Explain the process of synaptic transmission
Electrical impulse (action potential) travels down neuron, until neuron becomes positively charged relative to the outside. When the action potential reaches the terminal of the neuron it triggers the release of neurotransmitters which cross the synaptic gap between neurons chemically. The neurotransmitters then bind to receptor sites on the post synaptic neuron where an electrical impulse is either triggered or prevented depending on whether the neurone is more excitatory (e.g adrenaline) or more inhibitory (e.g serotonin)
104
What is the endocrine system
Made up of glands that secrete hormones. Works alongside the nervous system to control physiological processes using blood vessels to deliver hormones to target sites.
Operates a system of negative feedback that maintains a stable balance of the hormones that are in the body
105
What is the hypothalamus role in the endocrine system
Controlling the pituitary gland (the control centre of the endocrine system)
106
Give two examples of glands and hormones in the endocrine system
The pituitary gland produces ACTH in response to stress. ACTH travels to the adrenal glands where cortisol is released. It also produces hormones involved in reproductive system and sexual characteristics LH and FSH
Testes - male reproductive glands produces testosterone which is responsible for male characteristics such as facial hair, deep voice and the growth spurt that occurs during puberty. It also has a role in sex drive, sperm production and muscle growth
107
What is the fight or flight response
A stress response triggered when we experience stressful situations. May be a physical or psychological threat.
Once a threat is detected the hypothalamus activates the sympathetic branch of the autonomic nervous system which causes the adrenal medulla to release adrenaline and noradrenaline which increases heart rate, dilates pupils, inhibits digestion.
Once threat has passed parasympathetic branch of autonomic nervous system returns body to resting state.
108
What is the body’s short term stress response
FIGHT OR FLIGHT
( Sympathomedullary pathway)
Hypothalamus triggers sympathetic branch of autonomic nervous system which causes the adrenal medulla to release adrenaline and noradrenaline which increases heart rate, increases breathing rate, dilates pupils and produces sweat.
Once threat passes, parasympathetic branch of autonomic nervous system returns body to resting state
109
What’s the body’s long term stress response
Hypo-pituitary adrenal system
Hypothalamus secretes CRH to pituitary gland which releases ACTH which triggers adrenal cortex to release cortisol which suppresses the immune system
110
What is the role of adrenaline
Adrenaline is a hormone that prepares body for action.
Increases heart rate - to increase blood flow to organs and increase movement of adrenaline around body
Increase respiratory rates - to increase oxygen rates
Pupil dilation - to increase light entry into the eye and enhance vision
Inhibit digestion - to increase energy for other functions
111
Evaluate the fight or flight response
Weakness - does not explain stress response in females. Taylor et al suggested women adopt ‘tend and befriend’ response in stressful situations influenced by oxytocin that brings about bonding and caring behaviour. Increases relaxation and reduces fear. Suggests women are more likely to protect offspring and form alliances with other women rather than fight or flight. However this is a strength as has prompted more recent research which has provided alternative explenation for women
Weakness - initial response may not be fight or flight but freeze. Gray suggests first response to danger is to freeze to avoid confrontation all together. During the freeze humans assess the situation to decide best course of action for particular threat. Suggests fight or flight explanation of behaviour is limited and doesn’t fully explain complex cognitive biological factors that underpin stress response.
112
What is spatial resolution like in EEG and ERP
Poor spatial resolution, only detect activity in superficial regions of the brain. Consequently EEG and ERP are unable to provide information on what is happening in the deeper regions of the brain such as the thalamus, making this technique limited in comparison to fMRI
113
What is temporal resolution
Refers to the accuracy of the scanner in relation of time (how quickly scanner can detect change in brain activity)
114
What is temporal resolution like in fMRI
Poor temporal resolution of 1-4seconds
Psychologists unable to predict with a high degree of accuracy the onset of brain activity
115
What is temporal resolution like in EWG and ERP
Good temporal resolution. Readings taken every millisecond meaning brains activity can be recorded in real time opposed to looking at a passive brain.
Leads to accurate measurements of electrical activity when undertaking a specific task
However EEG and ERP are uncomfortable so patients discomfort may affect cognitive responses
116
Is fMRI invasive
Non-invasive
Does not use radiation of involve inserting instruments into the brain and is virtually risk free
This allows participants to undertake fMRI scans which helps psychologists gather further data and helps develop understanding of localisation of function
117
Is EEG AND ERP invasive
Non-invasive so virtually risk free
This allows more patients to undertake EEG and ERP which could help psychologists gather further data on functioning of human brain and therefore develop understanding of different psychological phenomena such as sleeping and Alzheimer’s
118
Is post mortem invasive
Yes however it’s not an issue as the patient is no longer alive. However ethical issues in relation to consent as many post mortems are carried out on patients with severe psychological deficits who would be unable to provide fully informed consent
119
Can causation be determined in fMRI
fMRI do not provide direct measure of neural activity, simply measure changes in blood flow so it’s impossible to infer causation at a neural level. While any change in blood flow may indicate activity within a certain brain area, psychologists are unable to conclude whether this brain region is associated with a particular function
120
Can causation be determined from EEG
Electrical activity often detected in several regions of brain simultaneously - making it difficult to pinpoint activity in the brain in response to specific stimulus . Making cause and effect difficult
121
Can causation be determined in ERP
ERP provide very specific measurement of neural processes in response to specific experimental manipulation. Research can pinpoint activity produced by the brain in response to specific stimulus which enables cause and effect to be determined
122
Can causation be determined in post mortem exams
The deficit a patient experiences in their lifetime may not be linked to deficits found in the brain. The deficits reported could have been the result of another illness so psychologists are unable to conclude if the deficit is caused by brain damage
123
What is a biological rhythm
Any activity or process that occurs within the body at regular intervals. Controlled by internal structures and processed but also influenced by factors outside the body
124
What is a circadian rhythm
The sleep wake cycle
Core body temperature
125
Describe the sleep wake cycle
An internal body clock called the suprachiasmatic nucleus (SCN) in the hypothalamus controls the sleep wake cycle. The SCN is located above the hypothalamus just above the optic nerves from each eye cross over known as the optic chiasm
SCN receives info about light from eyes via optic nerve, even when our eyes are shut. If our internal clock is running slow then morning light automatically moves the body clock ahead putting the rhythm in sync with the outside world.
At night when level of light reduces SCN sends signals to the pineal gland instructing it to increase production of hormone melatonin.
Melatonin induces sleep by inhibiting the brain mechanisms that keep us awake. When level of light begins to increase, melatonin reduces and we start to feel more awake
126
Evaluate the sleep wake cycle
Supportive evidence - from animal studies. Mutated hamsters specially bred to have SCN that produced sleep wake cycle of 20 hours. When cells from their SCN were transplanted to normal hamsters. The normal hamsters took on the new shorter sleep cycle. This confirms SCN plays an important role in controlling circadian rhythms such as sleep wake cycle
Practical applications. Increased our understanding of the difficulties people face when having to function against naturally occurring circadian rhythms. People working nights shifts need to be alert in the night so strategies such as having very bright lights in hospital had helped these workers. Research had positive implications for the economy for productivity of shift workers
127
What is the SCN and where is it located
Suprachiasmatic located within the hypothalamus above where the optic nerves from the eyes cross over
128
Describe the core body temperature cycle
Normal body temperature is 37° but has a circadian rhythm across 24 hours and core temperatures vary in a regular pattern
It is highest at 6pm -38°
Lowest at 4am - 36°
Influenced by external temperature and maintained via homeostasis
Sleep is linked to body temperature
Sleep typically occurs when body temperature starts to drop and body temperature rises at end of sleep cycle
129
What are infradian rhythms
Menstrual cycle
Seasonal affective disorder
130
What is normal body temperature
37°
131
How is body temperature maintained
Homeostasis and influenced by external temperature
132
Describe the menstrual cycle
Average length is 28 days but this can vary from 23 days to 36
Biological rhythm characterised by fluctuating hormone levels that regulate ovulation.
Pituitary gland releases follicle stimulating hormone and luteinising hormone which stimulate follicle in one ovary to ripen an egg and trigger the release of oestrogen
Once egg ripened, progesterone is released which prepares uterus for pregnancy
If pregnancy does not occur progesterone is reduced resulting in uterus lining being shed
Menstrual cycle also influenced by external factors. Phernomones are similar to hormones but act on the body of a person close by and not person producing them
133
Evaluate the menstrual cycle
Supportive evidence for pheromones as an external factor influencing timings of menstrual cycles. Russell found females menstrual cycles synchronise with each others through odour exposure. Suggests the synchronisation of menstrual cycles can be affected by pheromones. Findings indicate external factors must be taken into consideration when investigating infradian rhythms as opposed to only considering endogenous influence
Challenging evidence claim pheromones lead to menstrual synchrony. One study examined a women’s basketball team for an extended time and found no correlation between menstrual patterns. Suggests external factors may have less of an impact on this infradian rhythm then some suggest
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Describe seasonal affective disorder
Seasonal affective disorder is an infradian rhythm with a cycle of a year
It is a mental illness that brings about depressive symptoms such as low mood lack of interest and reduced activity
It occurs when the hours of daylight reduce so is experienced in winter months
It is triggered by melatonin which is a hormone produced by the pineal gland, in winter melatonin is produced for longer and had an effect for suppressing serotonin production
Low serotonin is associated with depression
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What are the small gaps called in myelin sheath
Ranvier
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What is summation
Receptors on post synaptic neuron stimulated by excitatory and inhibitory neurotransmitters at same time
If more excitatory - more likely to generate electrical impulse
If more inhibitory - less likely to generate electrical impulse
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What are endogenous pacemakers
Internal mechanism that govern biological rhythms
suprachiasmatic nucleus most likely endogenous pacemaker for sleep wake cycle.
Located in hypothalamus above optic nerves receives info about light via optic nerve even when eyes shut
If internal body clock running slow, morning light automatically puts body clock ahead to put in rhythm with world
When light reduces at night pineal gland secretes melatonin to inhibit brain mechanisms keeping us awake.
When light comes back melatonin production stops, we feel more awake
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What are exogenous zeitgebers
Sun in exogenous zeitgeber in human sleep wake cycle.
Sunlight effects suprachiasmatic nucleus like resetting a clock that runs a little slow to the correct time each day.
Special cells in eye detect brightness of light, containing protein called melanospin that transmits signals about light to SCN
Social cues also act as exogenous zeitgebers such as eating and habit influence
If we experience mismatch in endogenous pacemaker and exogenous zeitgeber such as travelling across time zones, our sleep wake cycle quickly becomes aligned to new external cues known as entrainment
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3 evaluation points endogenous pacemakers
Supportive evidence mutant hamsters with sleep cycle of 20 hours, when cells of these put in normal hamsters, they changed to 20 hour sleep cycle too
Inappropriate to generalise animal studies to human. Human sleep cycle influenced by free will and social factors such as staying up late
Supportive evidence from Michel Siffre who spent time living underground to examine effects of sleep cycle without external cues. After months he had cycle of 25 hours
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3 evaluation points exogenous zeitgebers
Practical applications - night shift workers required to be alert at night, working in very bright light helps focus, light can also help reduce jet lag. Effectiveness of practical applications suggests exogenous zeitgebers play important role in sleep wake cycle
Prac applications into effect of social cues. Jet lag best dealt with by adopting to local eating and sleeping times rather than responding to internal times. Suggests exposure to exogenous zeitgeber effective in entraining sleep wake cycle
Challenging evidence. Miles described case of young man blind from birth with circadian rhythm of 25 hours. Despite exposure to social cues his sleep wake cycle could not be adjusted. He had to take sedatives at night and stimulants in morning to keep pace with 24 hour world. Suggest individual differences may alter exogenous zeitgeber impact on sleep wake cycle
