Biopyschology Flashcards

Question

Excitation and Inhibition with Neurones

Answer 1

Neurotransmitters either have an excitatory or inhibition effect on the neighbouring neurone Serotonin causes inhibition in the receiving neurone, resulting in the neurone become more negatively charged and so less likely to fire Adrenaline (both a hormone and neurotransmitter) causes excitation in the postsynaptic neurone, resulting in the neurone becoming more positively charged and more likely fire

Answer 2

Whether a postsynaptic neurone fires is decided by the process of summation The excitatory and inhibitory influences are summed (added up) - if the net effect on the postsynaptic neurone is inhibitory then it is less likely to fire - if the net effect on the postsynaptic neurone is excitatory then it is more likely to fire This happens by the inside of the postsynaptic neurone

Answer 3

Summary: brain analysed after death to determine whether certain observed behaviour during a person’s lifetime can be linked to structural abnormalities in the brain Details: used to establish underlying neurobiology of a particular behaviour (e.g. researchers might study a person who displays behaviours while they are alive that suggest possible underlying brain damage) So when the person dies, the researcher can examine the brain of these individuals and look for abnormalities that might have explained their behaviour (and which are not found in control patients) An early example of this method was Broca’s work with an patient called Tan, who displayed speech problems when he was alive - found to have lesions in the area of the brain that is now known to be the Broca’s area - important area for speech production Have also made it possible to identify some of the areas of the brain responsible for memory and has also been used to establish a link between psychiatric disorders and underlying brain abnormalities

Answer 4

A strength of using post Mortem examinations is that they allow for a more detailed examination of anatomical and neurochemical aspects of the brain that would not be possible with non-invasive scanning methods For example, it enables researchers to examine deeper regions of the brain such as the hypothalamus and hippocampus, that would not be accessible with non-invasive methods, which pose great risks This is a strength because it allows psychologists to gain a deeper understanding of the role of the brain in human development, behaviour and abnormality Post mortem examinations have played a central role in developing understanding of schizophrenia For example, Harrison (2000) suggests that asa direct result of post mortem examinations, researchers have discovered structural abnormalities of the brain and have found evidence of neurotransmitters, both of which are associated with the disorder. This is a strength because gaining knowledge has not only developed psychologists understanding of why sz developed, it allows for the development of more successful treatment methods

Answer 5

A limitation of Post Mortem examinations is that they can sometimes lead to inaccurate data and findings For example, length of time between death and Post Mortem examinations, drug treatment and age of death are all confounding influences of any difference between case and controls This is a limitation because the findings obtained from Post-Mortem examinations may be criticised as lacking internal validity making it difficult for conclusions and cause and effect to be drawn A further weakness is that the approach is retrospective For example, due to the fact that the individual is already dead, the researcher is unable to follow up anything that arises from the post Mortem concerning a possible relationship between brain abnormalities and cognitive functioning This is a limitation because it means that the conclusions that can be dawn from post Mortem examinations are often limited

Answer 6

Summary: a record of tiny electrical impulses produced by the brain’s activity By measuring characteristics though have patterns, the EEG can help diagnose certain conditions in the brain Detail: measure electrical activity in the brain Electrodes (placed on top of the scalp) detect small extricate changes resulting from the activity of the brain cells When electrical signals from the electrodes are graphed over a period of time, the resulting representation is called an ECG ECG activity can be used to detect different types of brain disorders (e.g.g epilepsy) or to diagnose other disorders that influence brain activity (e.g. Alzheimer’s) The four basic ECG patterns are: - alpha (awake but relaxed) - beta (awake but physiologically aroused) - delta and theta waves (sleeping) When a person is moving from light sleep to deep sleep, the occurrence of alpha waves decrease and are replaced by theta and then delta waves

Answer 7

A strength of using ECG to measure brain activity is that is created a measure of brain activity functioning in real time (high temporal resolution) For example, the ECG canine takes a reading of the active brain rather than a passive brain This is a strength because the researcher can accurately measure a particular task or activity with the brain activity associated with it A strength of using ECG machines is that they are useful when trying to make a clinical diagnosis For example, epileptic seizures are caused by disturbed brain activity which means that the normal ECG reading suddenly changes This is a strength because ECG machines can help diagnose whether someone is experiencing epileptic seizures or other brain activity

Answer 8

A problem with using ECG readings/machines is that they can only detect activity in superficial regions of the brain For example, the ECG cannot reveal what is going on in deeper regions of the brain such as the hypothalamus or hippocampus. This is a weakness because it means that the information gained form ECG machines about brain activity is often limited (unless more invasive procedures are used e.g. inserting electrodes into the brain to measure deeper brain activity One disadvantage of ECG is that it has poor spatial resolution Spatial resolution refers to the smallest feature (or measurement) that a scanner can detect and is an important feature of brain scanning techniques. Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy. ECGs only detect the activity in superficial regions of the brain Consequently, ECGs are unable to provide information on what his happening in the deeper regions of the brain (such as the hypothalamus), making this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2mm

Answer 9

Summary: Isolating the electrophysiology response of the brain to specific sensory, cognitive or motor event by statistically analysing the ERP data Detail: EPRs are small voltage changes in the brain that are triggered by specific events or stimuli (e.g. cognitive processing of a specific stimuli) EPRs are difficult to pick out from all the other electrical activity being generates in the brain at a given time To establish a specific response to a target stimulus required many presentations of the stimulus are these responses are then averaged together any extraneous neural activity that is not related to to the specific stimulus will not occur consistently, whereas activity linked to the stimulus will - this has the effect of cancelling out the background neural “noise”, making the specific response to the stimulus stand out more clearly EPRs can be split into 2 categories: 1 - waves occurring in the first 100 milliseconds after presentation of the stimulus are termed ‘sensory ERPs’ as they reflect an initial response to the physical characteristic of the stimulus 2 - ERPs generated after the first 100 milliseconds reflect the manner in which the participant evaluated the stimulus and are termed ‘cognitive ERPs’ as they are demonstrating information processing

Answer 10

An advantage of the ERP technique is that is has good temporal resolution It takes readings very millisecond, meaning it can record the brain’s activity in real time as opposed to looking at a passive brain This leads to an accurate measurement of electrical activity when undertaking a specific task An advantage of the ERP is that it is an non-invasive technique I like other scanning techniques, such as Positron Emission Tomography (PET), ERP does not use radiation or involve inserting instruments directly into the brain and are therefore virtually risk-free Furthermore, ERPs are much cheaper techniques in comparison with the fMRI scanning and are therefore more readily available Consequently, this should allow more patients/ppts to undertake ERPs, which could help psychologists to gather further data on the functioning human brain and therefore develop our understanding of different psychological phenomena, such as sleeping, and different disorders like Alzheimer’s

Answer 11

One disadvantage of ERP is that it has poor spatial resolution Spatial resolution refers to the smallest feature (or measurement) that a scanner can detect, and is an important feature or brain scanning techniques. Greatest spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy ERPs only detect activity in superficial regions of the brain. Consequently, EEGS and ERPs are unable to provide information on what is happening in the deeper regions of the brain (such as the hypothalamus), making this technique limited in comparison to the fMRI, which has a spatial resolution of 1-2 mm A further weakness of using ERPS is that the output can only be interpreted by a trained professional For example, psychologists using ERPs require intense and expensive training in order to fully appreciate the activity measure from the ERP This is a weakness because such training can increase the cost of research and with limited funding in specific research areas, this can minimise the use of ERPs (attempting to save money)

Answer 12

Summary: method used to measure brain activity while a person is performing a task Detects radio waves from changing magnetic fields which enables researchers to detect which areas of the brain are rich in oxygen (and therefore active) Detail: a technique for measuring changes in brain activity while a person performs a task Does this by measuring changes in blood flow in particular areas of the brain (indicates oxygen in the area) If a particular area of the brain becomes more active, there is increased demand for oxygen in that area The brain responds to this extra demand by increasing blood flow, delivering oxygen in the red blood cells As a result in these changes in blood flow, researchers are able to produce maps showing which areas of the brain are involved in particular mental activity

Answer 13

FMRI scans can be praised for being non-invasive For example, it does not involve the insertion of any instruments into the body, nor does it expose the brain to potentially harmful radiation as is the case with some other scanning techniques This is a strength because it means that individual’s behaviours can be investigated without their physical, mental or psychological health being places at risk FMRI offers are more objective and reliable measure of psychological processes than is possible with verbal reports For example, blood volume can be accurately measures to see which parts of the brain are being utilised in certain tasks so research using fMRI scans are not simply relying of observations of the ppts behaviour or self reports from the ppts themselves This is a strength because it means that fMRIs are a useful way of investigating psychological phenomena that people would not be capable of providing in verbal reports whilst also removing any chance of bias (from observations/self-reports) FMRI scans have good spatial resolution Spatial resolution refers To the smallest feature (or measurement) that at scanner can detect, and is an important feature of brain scanning techniques. Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy. FMRI scans have a spatial resolution of approx 1-2 mm which is significantly greater than other techniques (EEG, ERP, etc.) Consequently, psychologists can determine the activity of different brain regions with greater accuracy when using fMRI, in comparison to when using EEG and/or ERP

Answer 14

FMRIs are not a direct measure of neural activity in particular brain areas For example, fMRIs only measure changes in blood flow in the brain which makes interpreting fMRI scans high complex This is na weakness because it is not truly a quantitive measure of mental activity in these brain areas FMRI scans have poor temporal resolution Temporal resolution refers to the accuracy of the scanner in relation to time, or how quickly the scanner can detect changes in brain activity FMRI scans have a temporal resolution of 1-4 seconds which is worse than other techniques (e.g. EEG/ERP which have a temporal resolution of 1-10 milliseconds) Consequently, psychologists are unable to predict with a high degree of accuracy the onset of brain activity The sample sizes for fMRI research are often small/unrepresentative For example, research usually has a limited amount of funding an using fMRI scans often requires lots of money (for upkeep of tigger machines, training for researchers to learn how to effectively use the machines) This is a weakness because this makes the research difficult to generalise/gives research low population validity

Answer 15

Localisation of function refers to the theory that functions such as movement, speech and memory are performed in distinct regions of the brain (localised) the opposite view is that the brain acts holistically to perform functions Different areas within the localisation theory are: - different regions of the brain - functions that are associates with those regions - the extent to which the research evidence support localisation of function

Answer 16

Our brains are divided into 2 symmetrical halves - the left and right hemisphere There is some hemispheric lateralisation - i.e. some of our physical and and psychological functions are controlled or dominated by a particular hemisphere - for example, language centres are found in the left hemisphere and Visio spatial tasks ate best performed by the right As a general rule, each hemisphere controls the opposite (contralateral- contralateralised wiring) side of the body

Answer 17

The cortex (outer layer of the brain) of both hemispheres is subdivided into four centres, or lobes, of the brain Each of these loaves is associated with different g functions, and damage to that specific areas in the lobes means that the functions associated with that area will also be affected

Answer 18

Lobe - frontal Area - found at the back of the frontal lobe Function - controls voluntary movement in the opposite side of the body Results of damage - loss of muscle function (muscles aren’t damaged - your brain that controls them is) - this could be loss of control over fine motor movements u to paralysis following severe trauma - effects are in opposite side of body to damage

Answer 19

Lobe - parietal Area - found at the front of the parietal lobe, separates from the motor area by a fold called the central sulcus Function - detects sensations (e.g. touch, heat, pressure) from the opposite side of the body Result of damage - loss of sensation - neglect symptom - reduced awareness of stimuli - agnostic - inability to identify objects and faces (Effects in opposite side to damage)

Answer 20

Lobe - occipital Area - found at back of the occipital lobe Function - Brain’s visual processing centre - each hemisphere’s occipital lobe received infro from the contra lateral visual field Result of damage - leads to partial or complete lindens - called cortical blindness —> the person s unable to see but there is no damage to the structure of the eye

Answer 21

Lobe - temporal Area - found at the top of the temporal love Function - receives and analyses speech-based info Result of damage - leads to partial or complete hearing loss - known as cortical blindness —> person is unable to hear but there is no damage to the structure of the ear

Answer 22

Unlike the motor area, somatosensory area, visual area and auditory rea, which are all found in both hemispheres, in most people language is restricted to the left hand side of the brain The 2 language centres are Broca’s area and Wernicke’s area

Answer 23

Located in left frontal lobe Responsible for speech production Damage results in Broca’s aphasia: - patient understands wat is being said to them - however, their own speech is characterised by being slow, laborious and lacking in fluency - often have difficulty with prepositions (positioning words) and conjunctions (connecting, joining words) - demonstrated by Broca’s famous patient - the case of ‘Tan”

Answer 24

Located in the left temporal lobe Responsible for speech comprehension Damage results in Wernicke’s aphasia - patient has difficulty understanding speech However, they have no problem in producing speech - as a result, the speech they produce i fluent but meaningless and will often contain neologisms (nonsense words)

Answer 25

Clinical case study research demonstrates loss of certain functions if damage is caused to particular areas of the brain For example: - the case of Tan )aphasia) - the case of Clive Wearing (amnesia - hippocampus) - Phineas Gage (frontal lobe damage) This is a strength of localisation theory because these case studies do suggest that these functions are localised in certain areas However, these individuals experience very specific Bain damage - their brain damage is specific to them Are we able to to take these very specific and personal findings and generalise them to all cases f brain damage in support of the theory

Answer 26

Brain scan reserach further supports these case studies by demonstrating how many language are localised to particular areas of the brain For example: - healthy ppts show activation in Broca’s area during a reading out loud task and Wernicke’s area during a listening task —> Peterson et al, 1988 (used brain fMRI scans) - there is activation of different parts of the prefrontal cortex when accessing semantic and episodic memories (Bucker & Peterson, 1996) This type of research is a strength because it is much more scientific and objective (unlike case studies that are subjective) No room for bias in interpreting results Results the brain scans show cannot be interpreted in different ways - the results are what they are

Answer 27

Neurosurgery is based on theory of localisation It works by destroying parts of the brain that are thought to contribute to psychological problems For example, in OCD, a region of brain called cingulate gyrus appears to be more active. The bilateral cingulotomy is designed to surgically interrupt this circuit. Surgeons can either burn away tissue by heating the tip of the electrode, or use a non-invasive tool known as a game knife to focus beam of radiation at the target site. An alternative is the capsulotomy where surgeons insert probes through the top of the skull and down into the capsule, a region of the brain near the hypothalamus that is part of the circuit. They then heat the tips of the probes, burning away tiny portions of tissue In general review of research, Cogrove and Rauch (2001) sported thar cingulomoty was effective in 56% of OCD and capsulotomy in 67% The surgery wouldn’t work if localisation theory wasn’t true If this area of the brain wasn’t acclimated with OCD then the surgery wouldn’t work So it must mean that this area of the brain is specific to that function No other functions damaged in the surgery, which you would expect if holistic theory was true However, you would expect all patients to have been helped but this wasn’t the case, going against localisation theory

Answer 28

Some recent research with more advanced brain imaging techniques has suggested that lanaguge systems are more distributes rather than being localised to Broca’s and Wernicke’s areas - one 2106 review found only 2% modern researchers think that language is completely controlled by these areas Seems as of language functioning is more widely distributed with ‘language streams’ being identified in regions in the right hemisphere ad subcortical areas such as the thalamus Contradicts localisation theory although as motor and somatosensory functions are highly localised, these findings may actually suggests that the correct approach in arguing for localised vs holistic nature of brain is dependent on the function we are considering

Answer 29

Lashely trained rates to run around maze and destroyed areas of their brain cortex (between 10% to 50%) destroying tissue in almost every area that allowed rats to stay alive Found that is was the amount of brain destroyed, not the specific part of the brain that was destroyed, which led to the worsening of performance Lashely concluded that higher cognitive processes, such as learning and memory aren’t localised but are instead distributed in a more holistic way across brain and that any healthy area of the cortex can perform damaged areas However, maybe the brain compensates if it is over damaged We are humans, not rats

Answer 30

Compared to the left hemisphere, the right hemisphere can only produce rudimentary words and phrases However, it does contribute emotional context to what is being sad (i.e. interrogative, happy or sad tone of voice, understanding humour, Sarcasm, metaphors and in direct requests) This has led to suggestions that left hemisphere is the analyser and right hemisphere is the synthesiser which in turn led to idea that left Brain people are more scientific ad logical and right brain people who are more creative In most individuals without sz, the left hemisphere is slightly larger than the right hemisphere (ceberal asymmetry) However in some individuals with sz, the right hemisphere is notably larger than the left (reversed cerebral asymmetry) This deterioration to left hemisphere could lead to poverty of language (alogila) which is often seen in sz

Answer 31

However, one weakened is that this idea that the left hemisphere is the analyser and the right hemisphere is the synthesiser is wrong Research suggests that people don’t have a dominant side of their scans which creates a different personality. Nielsen et al (2013) analysed brain scans for over 1000 people aged 7 to 29 and while they did find that people used certain hemispheres got certain tasks (which is evidence for lateralisation), there is no evidence of a dominant side. So mathematicians don’t have a dominant left hemisphere and artists don’t have a dominant right side Suggests the notion of right or left brained people is wrong

Answer 32

While language is lateralised, many other functions aren’t - motor, somatosensory and vision areas appear in both hemispheres of the brain In case of motor area, there is contractural wiring - idea that fright hemisphere control’s movement left of left side of body and vice versa In case of vision, it’s even more complex Vision and both contralateral (opposite side wiring) and ipsilateral (same side wiring) Each eye has left visual field and right visual field from which it receives light The left visual field of both eyes is connected to the right hemisphere The right visual field of both eyes is connected to left hemisphere This enables the visual areas to compare slightly different perspective from each eye and Aidan’s depth perception There is similar conteralateral and ipsilateral wiring for auditory input to the auditory area which helps us locate the source of sounds

Answer 33

A strength is that there is empirical research evidence that suggests the two hemispheres do process information differently, this isn’t just theoretical model of how Brain processes information Fink et al (1996) used PET scabs to identify which brain areas were active during a visual processing task. When asked to focus on finer details in an image (e.g. individual trees) showed regions of left hemisphere are active. When asked to focus on global detail (e.g. the whole forest) regions of the right hemisphere are more active At least as far as visual processing is concerned, hemispheric lateralisation is a feature - PET scans show objectivity however lack mundane realism There is research to support lateralisation can actually change over time Szaflarski et al (2006) found language became more lateralised to left hemisphere with increasing age in children and adolescents but after age 25, lateralisation decreased with each decade of life

Answer 34

The corpus callosum is a large system of nerve fibres that connect the left and right hemisphere A split-brain operation involves severing this This is usually done to reduce epilepsy (as during an epileptic seizure the brain experiences excessive electrical activity between the hemispheres) This has provided neuroscientists and psychologists with a way of studying how the hemispheres function when they can’t communicate with each other

Answer 35

Sperry (1968) studies 11 split brain patients and compared to non-split brain patients Shown a computer screen where either rods or pictures to be shown to either the LVF or RVF Hands are on hidden objects - can’t be seen but can be felt (Order = scenario, the information is received by, the response of the ppt, explanation) Picture or word of an object is shown to ppt’s right visual field - the left hemisphere - the ppt could describe what they had seen, either verbally or in writing - this is because language is lateralised in the left hemisphere Paiute or word of an object is shown to the patients left visual field and asked to describe it - the right hemisphere - the ppt couldn’t describe they they had seen either verbally or in writing - this is because the information received by the right hemisphere couldn’t be transferred to language centre in left hemisphere because the corpus callosum have been served Picture or word of an object is shown to the patient’s left visual field and asked to select of matching object - the right hemisphere - the ppt couldn’t describe what they had seen but could select a matching object (e.g. a watch is they were shown a watch) or a semantically similar object (e.g. an ashtray is shown a cigarette) out of sight using their left hand - suggests that the right hemisphere does have language compression but not speech or writing Picture or word of an emotional object (e..g a nude pinup picture) is shown to the patient’s left visual field - the right hemisphere - the ppt couldn’t describe what they had seen but did have an emotional response e.g. giggling or blushing - this suggests that the right hemisphere appears to experience its own emotional reaction Conclusions - certain functions are lateralised in tge brain - support functions that the left hemisphere is verbal and the right side is ‘silent’

Answer 36

Research support from more recent research including work from Michael Gazzaniga (1989) He had the same findings as Sperry - could say words presented to the right visual field bu not the left visual field Also found that ppts could draw with their left hand words presented to the LVF showing, like Sperry said, the right hemisphere has language comprehension Shows external reliability as consistency over time, supporting research supported Lack of control over variables due to it being a quasi experiment A quasi experiment is the IV is a naturally occurring difference between groups of people For example, split-brain patients all had severe epilepsy and the neurotypical control groups didn’t This is a major confounding variable (as only the split-brain patients had epilepsy) and it could be being neurodivergent itself explains the split brain task results, not the actual split brain The research is oversimplified and the results are typical of the right-handed men

Answer 37

The brain isn’t s static organ and the functions and processes of the brain can change as a result of experience and injury Neural plasticity is the apparent ability of the brain to change and adapt its structures and processes as a result of experience and new learning This links directly to idea of functional recovery the way that certain ability of the brain may be moved or distributed rather than lost following trauma to the brain

Answer 38

As each neuron matures, it sends out multiple branches This plasticity (‘brain change’) increases the number of syntactic contacts from neuron to neuron This is important because synapses don’t just ‘pass messages’ from one neurone to another, they also help strengthen the connection between neurons The number of connections and the strength of those connections are linked to intelligence and other higher ability skills While plasticity occurs throughout life, it is especially relevant during the early “critical years” when brain plasticity enables the senses, language, and together skills develop Therefore than surprising that during infancy the brain experiences rapid growth in the number of synaptic connections At birth, each neuron in the cerebral cortex has approx 2,500 synapses By the time a child is 3, the number of synapses is approx 15,000 (6x as many) synapses per neuron The strength of synapses can be increased or decreased, depending on their activity levels Very active synapses are likely to become stronger, embedding knowledge, skills and memory further (long-term potentiation) Those that are less active tend to becom weaker (long-term depression) As we mature, the connections we don’t use are deleted This is called neural pruning (Purcell & Zukerman, 2011) - use it or lose it situation

Answer 39

When a neurone is activated e.g. by reading a piece of text, actin (a protein side cells) causes temporary movements on neurones towards other neurons with which they are connected This is quite normals and research by University of California found that this activation lasts up to 5 minutes and then disappears quite quickly But if the neurone isn stimulated repeatedly (by repeating task 4 times in one hour), the synapse would physically split, forming new synapses and a potentially permanent neural change So, we can physically consolidate a memory though repetition or exposure to experience

Answer 40

Long-tern synaptic plasticity forms the model for memory storage, and a famous study by Maguire et al. (2000) demonstrates this She studies 16 London taxi drivers and found the volume of grey matter (where there is a high concentration of neurones) in the posterior hippocampus of London taxi drivers’ brain was positively correlated with their time as a taxi drivers and that there were significant between the taxi drivers’ brains and those of controls It’s important to note that this area of the brain is involved in memory and spatial navigation This shows that the brain can permanently change in response to frequent explosive to a particular task

Answer 41

One strength of research into neural plasticity is there there is a large body of objective research supporting the theory that the brain can change and adapt as a result of experience and learning and this occurs across the lifespan and across a range of experiences - Mechelli et al. (2004) found that learning a second language increases the density of grey matter in the left parietal cortex and that this density is influence by the fluency attained (more fluent, more density) and the age at which the second language was learnt (younger age, more density) - Lazar et at. (2005) found how experienced meditators had a thicker cortex (the outer surface of the brain that is associated with higher level cognitive processes; this was especially thicker in arrears related to attention and sensory processing) compared to non-meditators - Draganski et al. (2006) imaged the brains of medical students three months before and after their final exams. Changes were seen to have occurred in the posterior hippocampus and the parietal cortex - Boyke (2008) found that event at 60+, learning a new skills (juggling) resulted in increased neural growth in the visual cortex - Bezzola et al. (2012) showed how 40 hours of golf training increased motor cortex activity in new golfers aged 40-60 - Kuhn et al. (2013) found significant increase in right hippocampal formation and the right prefrontal cortex in a video gaming training group (that trained for 2 months for at least 30 minutes per day with a platformer game) compared with a control group This is a strength because it shows there is a large body of objective, empirical evidence for neural plasticity

Answer 42

Neural plasticity isn’t always a good thing - it may have negative consequences For example, taking part in addictive behaviours (which activates the dopamine pathways in the mesolimbic system) can result in a umber of neural changes One of these is that the dopamine stimulated neurons in the area now the brain called the dorsal striatum which is involved in forming habitats and can lead to tolerance and relapse in addicts A second example is phantom limb pain syndrome, a condition in which patients experience sensation, whether painful or otherwise, in a limb that doesn’t exists It has been reported to occur in 80-100% of amputees and is often resistant to treatment The exact cause isn’t known but it is thought to be due to cortical reorganisation of the somatosensory cortex After an amputation the brain may remap that part of the body’s sensory circuitry to another part of the body In other words, because the amputated area is long longer able to receive sensory information, the information is referred elsewhere, from a missing hand ton a still-present cheek for example So when the check is touched, it’s as though the missing hand is also being touched Because this is yet another version of tangles sensory wires, the result can be pain This is a limitation because it suggests that brain plasticity isn’t always a good thing

Answer 43

An example of neural plasticity than can occur after trauma such as stroke or damage following injury Healthy brain areas may take over functions of those areas that are damaged, destroyed or missing It may do this by forming new synaptic connections close to the areas of damage These secondary neural pathways are activated to enable function to continue, often in the same way as before

Answer 44

1. Axonal sprouting - undamaged axons grow new nerve endings to reconnect neurones whose links were injured or severed - undamaged axons an also sprout nerves endings and connect with other undamaged nerve cells, forming new neural pathways to accomplish a needed function 2. Denervation suspersensitivity - undamaged axons that do a similar job to those that are damaged become aroused to a higher level to compensate for those that are lost - however this can have negative consequences e.g. being over sensitive to pain messages 3. Recruitment of homologous reads of the opposite side of the brain For example, if Broca’s area was damaged ……

Answer 45

Real-world applications. Neuroscientists have suggested that this process can occur quickly (spontaneous recovery) but then after weeks or months it can slow down, at which point rehabilitation therapy may be required to further recovery Understanding of the processes involved in plasticity and functional recovery has been helped contribute to neurorehabilitaion One such example is constraint-induced movement therapy to help patients who have had strokes, where they repeatedly practise using the affected part of their body (e.g. an arm) while the unaffected arm is restrained. Research has shown that CIMT significantly increases function and strength following several hours of therapy CIMT works because the repeated movement and work causes more actin the neurones and causing more downwards pressure to next neurone causing more neurone branches to synapses, causing more functional recovery Gives validity to functional recovery because it shows that it works in practice

Answer 46

However one point to bear in mind for functional recovery si that factors such as age and level of eduction may impact recovery rates Elbert et al (1994) concluded that the capacity for neural reorganisation is much greater in children than in adults, meaning that neural regeneration is less effective in older brains Schneider t al (2014) found that 40% of people who achieved a disability-free recovery had more than 16 years of education compared to 10% of those who had less than 12 years of eduction. Therefore, we must consider individual differences when assessing the likelihood of functional recovery in the brain after trauma It is also worth remembering that a lot of research studies into functional recovery is based on a small samples of patients or case studies of individual patients Less evidence gathered from small group, may be more biases likely such as gender or cultural biases, and therefore can’t be applied to general population

Answer 47

Take longer than 24 hours to complete

Answer 48

Governed by monthly changes in hormone levels The cycles refers to first day of women’s period to the day before her next period Typical menstrual cycle takes about 28 days to complete but can be anything from 14-60 days Further detail: The menstrual cycle is a monthly sequence of events in females During the cycle, an egg is released and the uterus is prepared for implantation is fertilisation happens Girls are born with around 1 million eggs already present in their ovaries There are 4 stages of the cycle Stage 1 - menstrual stage, bleeding starts (menstruation) on ay 1 and lasts for about 4 days, this is the uterus lining breaking down Stage 2 - follicular stage, the uterus forms a thick spongy lining ready for fertilised eggs, day 4-14 Stage 3 - ovulation phase, an egg develops and is released form an ovary (ovulation) into the uterine tube at about day 14 (peak fertility peak) Stage 4 - luteal phase, uterus lining maintained or about 14 more days to about day 28, if a fertilised egg doesn’t implant the uterus lining breaks down Hormones controlling menstrual cycle are made in the pituitary gland Follicle stimulating hormone (FSH) makes a follicle (egg plus surrounding cells) mature in the ovary, FSH is only made in first half of the cycle and inhibited later so only one follicle matures per cycle Luteinising hormone (LH) stimulates ovulation and inhibits FSH production, LH causes the remains of the follicle to develop into a structure called the corpus luteum The corpus luteum produces hormone oestrogen and progesterone, the control growth of uterus lining The levels of the 4 hormones fluctuate during the menstrual cycle

Answer 49

The menstrual cycle is an endogenous system, in that is it controlled by internal factors (hormones) However, it can be influenced by exogenous zetigebers, i.e. factors external to the body One such exogenous factor is the menstrual cycles of other women During their menstrual cycle, a woman will secrete pheromones Pheromones are substances which are secreted to the outside of the body by an individual and received by a second individual of the same species Stern & McMlintock (1998) demonstrated how menstrual cues May synchronise as a result of the influence of pheromones: - used 29 women with a history of irregular periods - samples of pheromones were gathered from 9 different ppts at different stages of the menstrual cycle - they were gathered by asking women: ~ place a cotton wool pad in their armpit of at least 8 hours on each day of their menstrual cycle - the pads where then treated with alcohol and frozen - on day 1, the remaining 20 women day day 1 of cycle pads rubbed on their upper lip - on day 2, they had day 2 of the women’s cycle pads rubbed on their upper lip and so on - found 68% of women experienced changes to their own menstrual cycle which brought them closer to the cycle of their ‘odour donor’ Also been suggested that male pheromones may also be an exogenous factor than can influence the menstrual cycle McClintock (1971) reported that women work withy men have much shorter menstrual cycles and suggested this could be because male pheromones may ‘reset’ a woman’s biological clock for her menstrual cycle

Answer 50

It may be that the role of pheromones play in menstrual cycle have an evolutionary basis Pregnancies may also become synchronised. In EEA (environment of evolutionary adaptive ness) a number of mothers would have died in childbirth while their child might have survived. This would allow other new mothers to feed the child so it survives and can be looked after and taken care of It is also advantageous for women to be around men to have much shorter menstrual cycles because they are fertile more often, so it increases their chances of a successful reproduction However, it is also worth remembering that there are methodological limitations of synchronisation studies There are many EVs and CVs that can effect changes to the menstrual cycle These can include: - stress - diet - life style - certain medications - perimenopausal This can explain why findings into synchronisation of menstrual cycles in women aren’t consistent - not all research have managed to replication these findings This a is a limitation because it doesn’t suggest that menstrual synchrony studies are flawed However, there is some evidence of reliable findings into this area For example, Stern and McClintock (1998) based their work on an earlier study by Russel et al (1980). Russell applied the pheromones of one women (using the same cotton pad technique) to a group of sexually inactive women every day for 5 months. There was also a control group of sexually inactive women who received same treatment but had a clean cotton pad rubbed on their upper lip. The ppts didn’t know which group they were in. A record was kept of their menstrual cycles and at the end of the experiment, four of of the five women in the pheromone group had menstrual cycles that synchronised within a day of the pheromone donors Shows reliability and therefore validity

Answer 51

Seasonal affective disorder (SAD) is a depressive disorder that is a type of infradian rhythm known as a circannual rhythm because it repeats on a yearly cycle Further information: - type of depression that comes and goes in a seasonal pattern, also sometimes known as winter depression, because symptoms are usually more apparent and more server during the winter time (symptoms can be felt in summer rather than winter, thought much less frequently) The evidence suggests that SAD is related to seasonal variations in productions of melatonin, which is a hormone secreted by the pineal gland Melatonin affects the production of the neurotransmitter serotonin which is implicated in depression Melatonin is produced predominantly at night (i.e. darkness) and so more is produced during the dark winter months There is a negative correlation between melatonin and serotonin - as melatonin goes up, serotonin goes down and mood goes down

Answer 52

Strength research into SAD is that theory has predictive validity The means theory can make accurate predications about occurrence of SAD For example, Terman (1988) found nearly 10% of those living in New Hampshire (a northern part of the US) experienced SAD, compared to only 2% in southern state of Florida This would be expected because New Hampshire in the north has shorter days in winter i.e. darker whereas Florida in the south has longer days than higher i.e. lighter This is a strength because it adds validity to the melatonin explanation of SAD Second strength is there is real-world applications with development of therapies specific for SAD Phototherapy (or light therapy), exposed patients being exposed to a box which stimulated very strong light to reset the body’s internal clock and is found to reduce effects of SAD in about 80% of people and is regarded as a safer treatment compared to antidepressants Both adds validity to theory that SAD is linked to lack of light and the impact that has on the production on both melatonin and serotonin, while also helping improve people’s quality of life However, some users of phototherapy report headache and eye strain In addition, research by Rohan et al (2009) compared people with SAD who where treated with phototherapy to a group who received CBT and found a relapse rate of 46% over successive winters for the phototherapy group compared to 27% of CBT group Both could be used - phototherapy is available short term and has 80% success rate - can be accessed very quickly upon relapse - CBT could be sued alongside this as it’s not as readily available but can help prevent relapse

Answer 53

Take less than 24 hours to complete - i.e. occur more than once over the course of the day

Answer 54

Sleep cycle is one of most intensively researched ultradian rhythms Researchers have found that there bare 5 stages in in sleep that are based on a 90 minute ultradian cycle - a cycle that continues throughout then course of the night Each of the 5 stages in the sleep cycle is characterised by a different level of brain wave activity These can be measured using EEGs: - measures electrical impulses in the brain using electrodes that are placed on the scalp

Answer 55

This is the only stage you are in once A light sleep from which you can be easily woken from - most people would deny being asleep The body releases Heart rate and temperature fail Hypnogogic state may occur - quite vivid perceptions e.g. falling sensation Myclonic jerks may occur Characterised by alpha waves (mid frequency - often around 8-12Hz, short amplitude) - associated with being relaxed

Answer 56

A light sleep from which you can be easily woken, although minor nosies probably won’t disturb you The body continues to relax Heart rate, blood pressure and temperature fall Characterised by alpha waves (high frequency, short amplitude) and sleep spindles (brain activity following muscle twitching, each lasting approx 25 seconds)

Answer 57

A deep sleep from which you can’t be easily woken During stage 4r sleep, body temperature, heart rate and blood pressure drop to their lowest point and growth hormones are secreted Sleep walking, sleep talking and night terrors can occur in stage 4 sleep - however its a dreamless stage of sleep Characterised by delta waves (low frequency - 0.5-4Hz, high amplitude) Also known as slow wave sleep (SWS)

Answer 58

Paradoxical sleep - deepest stage of sleep but brain waves that most closely resemble being awake Heart rate and blood pressure increase and breathing becomes faster and more regular Rapid eye movement, so also known as REM (rapid eye movement) sleep Body is paralysed - stop you acting out your dreams - links to sleep paralysis Dreaming occurs Hardest stage to wake someone from EEG activity of theta waves, which closely resembles activity in the awake brain

Answer 59

Strength is that research into sleep cycle has improved our understanding of age-related chnages in sleep For example, Obayan et al (2004) carried out meta-analysis of 65 studies of sleep patterns across the life span, with ppts aged from 5-102 years old. The most dramatic finding was decrease of SWS (stages 3&4) from 24% total at age 5 to 9% total at age 70. This streaky decrease in SWS is significant as early as age 30. As stage 4 appears to have a restoration purpose (growth hormones are released), this means that as we get older asleep has less and less or a restorative function. This may explain various issues in older age, such as a reduced alertness This is a strength because we can use this understanding gained from reserach to encourage people to make use of relaxation and medication as they get older to help increase SWS One limitation of ultradian rhythm research is that is has found significant variation between people For example, Tucker et al (2007) found large differences between ppts in terms of the duration of each sleep stage, particularly stages 3&4. It has been suggested that these differences are biologically determined This is a limitation because it makes it difficult to describe a ‘normal’ sleep cycle ultradian rhythm in any meaningful way Research into the sleep cycle is carried out in sleep labs using EEGs Strengths: - difference et variables such as noise, caffeine intake and screen time can be controlled for the gain accurate results ~ internal validity - no demand characteristics as it is rather difficult to change how much you sleep if you’re tired and you have no control over your sleep cycle Limitations: - sleep labs aren’t representative of sleep we get at home - sleep we get at home won’t have all these variables controlled ~ lacks external validity ~ cannot generalise - people may not sleep as well in a foreign environment ~ lack of internal validity

Answer 60

These occur across a 24-hour cycle

Answer 61

The most obvious and most researched example of a Circadian rhythm is the sleep-wake cycle We tend to go to bed and wake up at approx similar times each day The sleep-are cycle is also governed by endogenous pacemaker - a biological ‘clock’ called the SCN (suprachiasmatic nucleus) This is a small group of cells that lies within the hypothalamus, just above the optic chiasm which takes in information about the amount and quality of light taken in by the eye Light can rests the SCN, which suggests that daylight is an important exogenous zeitgiber in the sleep wake cycle

Answer 62

Michel Siffre, a French cave explorer, spent nearly 7 months living in a cave in Texas, deep underground with no exogenous zeitgebers to tell him time time it was - no natural light, no clocks, no TV, no radio He ate and slept when he wanted to, lights came on when he woke up and turned off when he went to sleep His Circadian rhythm sleep-wake cycle therefore allowed to ‘free-run’ At first, his sleep-wake cycle was fairly erratic, ranging from 25-32 hours It eventually smelled at 24.9 hours instead of 24 hours There have been other, similar results recorded For example, Weber (1979) had ppts spend 4 weeks in a bunker deprived of natural light, and again found that all (but one) ppts settled into a 24.9 sleep-wake cycle

Answer 63

1. Our natural sleep-wake cycle is longer than 24 hours 2. As his sleep-wake cycle was regularly 24.9 hours once it settled, this is evidence of an endogenous pacemaker playing a role in our sleep-wake cycle 3. However as we in real world we live to 24 hours, not 24.9 hours, this suggests that exogenous zeitgebers (external factors) also play a role 4. But we mustn’t overestimate the influence exogenous zeitgebers have on our internal biological clock Folk et al (1985) studied 12 people who lived in a dark cave for 3 weeks, in which clocks were provided They were asked to go to bed when the clock said 11:45pm and get up at 7:45am Unknown to ppts, the researchers sped the clocks up over the study to the point than an apparent 24 hour day was actually 22 hours 11 of the ppts were unable to comfortably adjust to a 22 hour day, showing that we have a strong internal biological clock that cannot be easily overridden by zeitgebers

Answer 64

The main strengths of research into circadian rhythms are the number of practical applications it has had, such as: 1. Medical treatment (general circadian rhythm research) 2. Shift work (sleep-wake cycle research) 3. Shifting the school day (sleep-wake cycle) Medical treatment: Circadian rhythms research has been used to improve medical treatment, as research helps us understand how circadian rhythms co-ordinate a number of the body’s basic processes such as heart rate, digestion and hormone levels. For example, the field of chronotherapeutics looks at how medical treatment can be administered in such a way that corresponds to a person’s biological treatments. Heart attacks are mostly likely to occur early in the morning (as blood clotting peaks in the morning), so taking aspirin last thing at night can reduce a risk of a heart attack (as aspirin reduces blood platelet activity) (Bonten et al, 2015) This is a strength because it shows that circadian rhythm research can help increase the effectiveness of medical treatments by considering the timing of drug treatments Shift work: A second strength of research into circadian rhythms is that has helped us understand the adverse consequences thar occur when they are disrupted (desynchronisation) For example, consider people working night shifts. They have to work when their body wants to sleep and they have to work sleep when their body wants to be awake. Night shift workers experience circadian trough with a period of reduced concentration at around 6am, meaning mistakes and accidents are most likely to occur (most lorry accidents occur between 4am and 7am). Research has also indicated that shift workers are three times more likely to develop heart disease compared to people who work typical working patterns. One suggestion has been to rotate shifts with the clock, i.e. a week of morning shifts, week afternoon shifts, then week of evening shifts then week night shifts and then back to morning shifts. Czeisler et al (1982) tested this in a chemical plant in Utah and found workers reported feeling better and less tired on the job and managers reported increased productivity and fewer errors. Night shift workers also have higher rates of mental healthy issues and divorce This is a strength because it shows the circadian rhythm research has real-work health and economic productivity for shift workers (Further research into desynchronisation has been carried out into jet lag. In jet lag, your body clock tells you it is one time but the external factors tell you it is a different time. This only occurs West to East (the worst) and East to West. People could use melatonin as a supplement to help them manage and reduce jet lag (the hormone that makes us sleepy). 1 2001 review looked at 10 studies in which people who were travelling used melatonin and were given it around the bed time of their new location. They reported significantly reduced jet lag) Shifting the school day: One strength of research into carcadian rhythms is that is has practical applications being able to be linked to the eduction system and the start times of schools For example, research has shown that teenagers need more sleep than people of other age groups, for a number of reasons. Firstly, during puberty the brain undergoes reorganisation, as said by researcher Neil Stanley, and sleep gives us the opportunity to do thus. Not only do teenagers go through the experience of changes in the brain and body, but they are also experiencing many other factors in their life that lead them to require to sleep longer, such as exams, the transition from childhood and adulthood and functioning in this new life with less emotional support than they were initially provided with. All of this makes a lot of energy and is also very stressful, and seep is important for processes such as memory and learning, dealing with emotions and repair and recuperation. With all of these processes requiring sleep, it explains why teenagers need a lot more sleep than others and therefore we can adapt the eduction system so that teenagers are able to get this extra sleep This is a strength because practical applications have emerged as a result of these research results. A few sixth form colleges have adapted the start time of their school day, starting at 10am, to allow their students longer to sleep in the morning so their body can undergo these processes, as well as improve their attention in lessons (reserach has shown that within our internal circadian rhythm, our peak attention time is 10am), allowing them to get the most out of their eduction

Answer 65

One limitation of research into circadian rhythms is that generalisations are difficult to make Cave and bunker studies are based on very small samples of ppts Other research suggests that sleep-wake cycles vary much more widely than these findings might initially suggest For example: - Czeisler et al (1999) found individual differences in sleep-wake cycles varying from 13 to 65 hours - Duffy et al (2001) found some people are ‘larks’ and others are ‘owls’ - Even Siffre (1999) observed that his own sleep-wake cycle had changed since he was a young man in the early 1960s This is a limitation because it means it’s difficult to use the research data to discuss anything more than averages, which may be be meaningless, meaning that the practical applications that’s have been developed from such research may not be as useful or as practical as we might think or want them to be

Answer 66

The internal body clock The sleep-wake cycle involves both the SCN and the pineal gland - biological processes that control our biological rhythms - included neural factors and hormones It works as follows to create our circadian sleep-wake cycle: 1. The optic chiasm takes in information about the amount and quality of light taken in by the eye 2. This information travels along the optic nerve into the SCN 3. The SCN passes the information to the pineal gland 4. The pineal gland secretes melatonin in relation y to the amount of light there is - There is a negative correlation here - less light, more melatonin 5. Melatonin induces sleep - levels rise from dusk and reach a critical level which makes us sleepy

Answer 67

There is a large body of evidence form animal studies that demonstrated the influence of SCN (endogenous pacemaker) on the sleep-wake cycle - we can generalise to humans because there are similar mechanisms in the mammalian brain here DeCoursey et al (2000) chipmunk study - 30 chipmunks had their SCN connections destroyed - returned to their natural environment and observed for 80 days - their sleep-wale cycle disappeared by the end of the 80days and a significant number had been killed by predators - they were awake and out and about when their predators were awake and hunting Ralph et al (1990) hamster study - mutant hamsters with 20 hour sleep-wake cycles were bred (they had polyphasic sleep-wake cycles) - SCN cells from foetal tissue of the mutant hamsters were transplanted into the brains of normal hamsters - these hamsters then took on the 20 hour sleep-wake cycle, instead of their usual polyphasic sleep-wake cycle, because the SCN controls the sleep-wake cycle

Answer 68

Research studies are reliable and have been backed up by a range of other studies: - Stephan & Sucker (1972) damaged the SCN in rats and found their sleep-ale cycle was disputed - Morgan (1995) removed the SCN from hamsters and found their sleep-wake cycle disappeared. They also transplanted;anted SCN from mutant hamsters bred to have shorter cycles. Their sleep-wake cycle returned but was shorter - Silver (1996) transplanted normal cells into hamsters bred to have mutant cycles and those who had had mutant SCN cells transplanted. They found normal polyphasic sleep-wake cycle returned Also shows that these have good predictive validity

Answer 69

However, one limitation is that research into endogenous pacemakers in the sleep-wake cycle has predominantly focused on the SCN in the brain but thus might be at the cost of minimising or ignoring other biological clocks we have in other parts of our bodies For example, until relatively recently, research that suggested the existence of circadian oscillators (biological clocks) in peripheral organs (e..g lungs, pancreas, skin) in mammals was largely dismissed. This was despite the fact there was increasing amount of research showing that these exist and that, while they are influence by the SCN, also act independently form it. For example, changing the feeding patterns of mice could alter the circadian rhythms in the liver by up to 12 hours while the rhythm of the SCN was unaffected This is a limitation because it means we might be ignoring other complex influences on our circadian rhythms Additionally, when studying the tole of endogenous pacemakers such as the SCN in our circadian rhythm sleep-wake cycle we cannot study these in isolation Even in the (rare) cave and bunker studies, where researchers such as Siffre attempted to remove as many exogenous zeitgebers as they could, there were still some zeitgebers e.g. the artificial lights that Siffre used, and it is entirely possible that these could have reset his biological clock. It is clear that in everyday life there in an interactionist system here - our pacemakers and zeitgebers do interact This is a limitation because it suggests that the more researchers attempt to isolate the influence of internal pacemakers, the lower the validity of the research

Answer 70

As we have seen, light is the key exogenous zeitgeber in our sleep wake cycle We can even recieve information about light from other parts of our body other than sour eyes Campbell and Murphy (1998) shows that light can be detected by skin receptors - they woke up 15 ppts at various times and each time they woke them, the shone a light pad on the back of their knees This changed their usual sleep-wake cycle by up to 3 hours The role of light being the main zeitgebers is supported by case study research For example, Miles et al (1977) documented the circadian rhythms of a man who has been bribed since birth He had a strong 24.9 hour sleep-wake y cycle despite the fact he was exposed to other exogenous zeitgebers such as clocks, alarms and radios He struggled to set his body to a 24 hour cycle so much that he had to use sedatives to sleep and stimulants in the morning to co-ordinate his sleep-wake cycle with that of the world around him This is strong evidence is the key exogenous factor in sleep-wake cycle, as it was the only exogenous ziethgeber he lacked However, light can’t be the only exogenous zeitgeber For example, people in the artic circle lie in a world of endless days in summer and endless night is winter, yet they are able to maintain a fairly regular sleep wake cycle This suggests that our sleep-wake cycle is primarily controlled by endogenous pacemakers than can override environmental changes in light Or it might suggest that there other other exogenous zeitgebers other than light that help people t maintain theirt circadian sleep-wake cycle, such as social cues e.g. meal times This can be seen in new Born babies who have random sleep-week cycles when they are born - circadian rhythms start to emerge about 6 weeks Within 10 weeks from this point, a baby’s circadian rhythm is pretty munch in line with parental schedules, including adult-determined mealtimes and bedtimes We can also see the effect of socials cues when dealing with jet lag This is caused by our internal body clock being out of sync with the external world, and it can have a negative impact on Alertness and performance An effect way of dealing with thus us to immediately adopt (even as soon as you get off the lane) to local times for eating and sleeping and ignoring your own internal feelings as much as you can

Biopyschology Flashcards

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