AO3: Biopsychology (Year 13) Flashcards
1
Q
Localisation of Function: Sur’s research provides a challenge to the theory of localisation of function
A
- E: In 2000, Sur did an experiment where he rewired the brains of ferrets so visual info was processed by the auditory cortex instead of the visual cortex and found that the ferrets were still able to see through their eyes
- E: The ferrets’ auditory cortex was able to process visual info which challenges the theory of localisation as if different functions were truly localised to specific areas of the brain then the ferrets wouldn’t have been able to see out of their eyes but because they could we know this isn’t the case. But even though the ferrets could see, their vision wasn’t as good as if the information was processed in the visual cortex which rather supports the theory of localisation of function as the newly recruited auditory cortex was not effective at assuming a function (visual processing) it lacked specialisation for. Moreover the auditory and visual cortexes have similar functions as the both process sensory info so further research would need to be done to see if an area with a completely different function (e.g. Broca’s area) could process visual info
- L: Sur’s research does challenge localisation of function but weakly due to the effectiveness of localisation
2
Q
Localisation of Function: Broca’s Research on Louis Leborgne provides support for localisation of function
A
- E: Leborgne had a speech impediment where he could understand language but could only respond with the word ‘tan’. After he died, Broca did research and found that this was the case because he had a lesion in what is now known as the Broca’s area
- E: Supports localisation of function by showing how specific functions are localised in the brain. Leborgne ‘s function of language production was localised to his Broca’s area which suggests that this is where speech production is localised. As well as this,
Leborgne was still able to understand language which suggest that the function of speech comprehension is localised to a different area of Leborgne’s brain that wasn’t damaged. However, the evidence is from a single case study so the findings can’t be generalised to people without lesions in the brain
3
Q
Localisation of Function: Issue is that is is a reductionist theory
A
- E: By itself the theory takes complex phenomena like language production and reduces it down to specific areas of the brain, e.g. the Broca’s area
- E: This shows localisation of function is reductionist as it takes complex phenomena and breaks it down to simple explanations. However, this doesn’t work for some complex functions in the brain like consciousness which can’t be reduced to specific regions in the brain suggesting it’s an emergent property that is a result of the brain as a whole rather than a specific area. But if this only applies to some complex brain functions then it doesn’t completely undermine localisation of function but suggests that it provides a limited explanation of the brain
4
Q
Plasticity and Functional Recovery: Sur’s animal research shows the extent of plasticity and functional recovery in the brain
A
- E: In 2000, Sur did an experiment where he rewired the brains of ferrets so visual info was processed by the auditory cortex instead of the visual cortex and found that the ferrets were still able to see through their eyes
- E: The fact that the auditory cortex was able to assume the function of another area of the brain that had been damaged (the visual cortex) provides support for functional recovery as it shows the ferret brains rearranged themselves to be able to recover the function of processing visual information. As a feature of plasticity is functional recovery this also provides support for plasticity. However even though the ferrets could see, their vision wasn’t as good as if the information was processed in the visual cortex which shows the limitations of functional recovery as although they were able to process their vison was really bad. Finally, this research is an animal study making it unwise to generalise the findings on functional recovery to humans.
5
Q
Plasticity and Functional Recovery: Research has shown the importance of age for plasticity and functional recovery
A
- E: In 2008, Marques de la Plata did research and found that those over 40 receiving treatment showed less functional recovery and also were more likely to decline in brain function over the next 5 years than those who received the same treatment but were under 40
- E: This shows younger brains are more capable of functional recovery and this tracks considering functional recovery is a feature of plasticity and younger brains are known to be more plastic so we can assume they would be better at rearranging the brain after an injury. However the research did show that brains over 40 were still able to functionally recover to a degree showing that all brains have an aspect of plasticity. A limitation of this study is that its a quasi experiment and since the IV is a pre-existing difference (age) there was no way to control the IV using random allocation which undermines internal validity
6
Q
Plasticity and Functional Recovery: A strength of research into plasticity and functional recovery is its real-life implications for neurorehabilitation
A
- E: Neurorehabilitation uses motor therapy and electrical stimulation of the brain to counter the negative effects in motor and cognitive functions following brain injury or strokes
- E: By understanding plasticity and functional recovery, researchers were able to come up with neurorehabilitation which shows the importance of research into plasticity and functional recover. Moreover this has economic implications as the cost of caring for those with brain injury can be significantly decreased if people recover and are able to care for themselves and even return to work so they can generate income for themselves
7
Q
Hemispheric Lateralisation and Split Brain Research: Sperry’s research into split brain patients demonstrated some of the ways in which hemispheric lateralisation occurs
A
- E: In a particular study, the split brain patients were shown pictures to their left or right visual field. When the photos where shown to their right eye (left hemisphere) the patients could describe them but when they were shown to the left eye (right hemisphere) they couldn’t however they could still match the image to an object
- E: This shows how certain functions are lateralised or bi-lateralised to different hemispheres in the brain. The patients could only verbally describe what they saw when the image was shown to their left hemisphere which suggests language productions is lateralised to the left hemisphere. This is further supported by the theory of localisation of function as the Broca’s area and Wernicke’s area are both found in the left hemisphere. Sperry’s manipulation of the IV (the visual stimuli) improves the credibility of the study as by doing this he was able to test each hemisphere which improves internal validity
8
Q
Hemispheric Lateralisation and Split Brain Research: Issues with generalisation
A
- E: Usually uses small samples (example being Sperry’s research which only used 11 split brain patients) and the participants have undergone a very specific surgery which is only used as a last resort for severe epilepsy
- E: Generalising findings on hemispheric lateralisation for non-split brain patients can be difficult when using a small unique sample so the research lacks population validity. However researchers don’t really have a choice but to use these small, unrepresentative samples because of the unique nature of split brain patients
9
Q
Hemispheric Lateralisation and Split Brain Research: Some research has challenged conventional wisdom on hemispheric lateralisation
A
- E: Kim Peek was born without a corpus callosum, meaning his hemispheres have been disconnected since birth and yet he has demonstrated many extraordinary mental abilities, e.g he can read the pages of a book in 8-10 seconds as he reads the right pages with his right eye and the left pages with his left eye
- E: This challenges the claim that language is lateralised to the left hemisphere as if Peek is able to read from his right eye (which under normal circumstances would connect to his left hemisphere where language processing is supposedly only lateralised to) then this suggests that his right hemisphere also has the capability to process language. However, Kim Peek’s situation is a single case study meaning there are issues with generalisation as one person can’t be representative of a whole population so this study only provides a weak challenge to hemispheric lateralisation
10
Q
Circadian Rhythms: Research by Siffre supports the idea the sleep/wake cycle is a circadian rhythm
A
- E: In 1962, Siffre lived in the Alps underground for 2 months with only a lamp and found his sleep/wake cycle increased to 25 hours
- E: Siffre’s research showed the sleep/wake cycle is free running as it stayed to roughly 24 hours when he was underground without the external cue of sunlight. The fact his sleep/wake cycle extended to 25 hours suggests that the free-running state of the sleep/wake cycle is more than 24 hours and the external cue of light is what keeps the cycle to 24 hours. Conclusions are undermined by the presence of the lamp as it acts as an extraneous variable which undermines the internal validity and the experiment also lacks population validity as Siffre only did the experiment on himself (can’t generalise findings)
- L: Research supports sleep/wake cycle as a circadian rhythm but support is limited due to lack of internal and population validity
11
Q
Circadian Rhythms: Research into Circadian Rhythms has important health implications
A
- E: Research on the effects of working night shifts (aka shift work) has found that those who work night shifts are 3x more likely to develop heart disease than those who don’t do shift work
- E: Shows that damaging our natural circadian rhythm can be dangerous to our health as night workers would have to stay awake when their free-running circadian rhythm would be telling them to sleep. This has economical impacts as it means more money would have to be spent on healthcare in the long run and more importantly those who would have been working are now economically inactive
- L: Demonstrates how research into circadian rhythms is very important
12
Q
Circadian Rhythms: Research has found individual differences in the timings of circadian rhythms
A
- E: In 2001, Duffy et al. did research and found ‘morning people’ wake up and go to bed earlier (roughly 6am and 10pm) whereas ‘evening people’ wake up and go to bed later (roughly 10am and 1am)
- E: By understanding how circadian rhythms vary for individuals it can benefit society as it would mean employers should tailor the working hours of employees to their circadian rhythm to maximise productivity and this in turn has economic implications
- L: This shows that taking the individual differences in the timings of circadian rhythms into account ultimately has beneficial social and economical implications for society
13
Q
Exogenous Zeitgebers/Endogenous Pacemakers: Research into the role of exogenous zeitgebers and endogenous pacemakers on the sleep/wake cycle has real-life implications
A
- E: Sleep deprivation has become a huge issue in the modern world as it is linked with every mental health issue and many physical health conditions
- E: Research into the role of exogenous zeitgebers and endogenous pacemakers on the sleep/wake cycle has showed an increase in blue light emitting devices (e.g.) are factors that impact sleep deprivation. This has allowed for information and guidance that will impact the physical and mental health of humans, as well as prescribing melatonin and other interventions, decreasing the impact of sleep deprivation in society
- L: There are social benefits that come from understanding the role of exogenous zeitgebers and endogenous pacemakers on the sleep/wake cycle
14
Q
Exogenous Zeitgebers/Endogenous Pacemakers: Research into the role of exogenous zeitgebers and endogenous pacemakers on the sleep/wake cycle illustrates the importance of an interactionist approach
A
- E: An interactionist approach challenges both sides of the nature vs nurture debate as it looks to see how biological and environmental factors interact
- E: It is impossible to explain the sleep/wake cycle using only biological or environmental factors as it uses both. The environmental stimuli (exogenous zeitgebers) interact with the biological structures (endogenous pacemakers, pineal gland) to regulate the sleep/wake cycle
- L: Therefore the role of exogenous zeitgebers and endogenous pacemakers on the sleep/wake cycle can only be understood using an interactionist approach
15
Q
Exogenous Zeitgebers/Endogenous Pacemakers: The importance of the SCN on the sleep/wake cycle been demonstrated in research
A
- E: In 2000, Decoursey did research where he cut the SCN connections of 30 chipmunks, observed them in their natural habitat for 80 days and found that the sleep/wake cycles of the chipmunks had been severely disrupted. Moreover, many of the chipmunks were killed by predators in the 80 days
- E: This shows the importance of the SCN (the body’s main pacemaker) as if the SCN wasn’t important, the chipmunks’ sleep/wake cycle wouldn’t have been impacted. Moreover, the deaths of the chipmunks implies that they were now awake at times when predators were also around which shows the sleep wake cycle of the chipmunks is naturally selected to increase survival advantage so the trait can be passed to offspring. However, this study was done on chipmunks, who are biologically different and have different environments to humans so the findings on the role of endogenous pacemakers in the biological processes of humans can’t be concluded from this study
- L: This study shows the role of the SCN in the sleep/wake cycle but it can’t be generalised to humans
16
Q
Ways of Studying the Brain (Post-Mortem): Limitation is the issue of Causation
A
- E: In post-mortem examinations, the brains of people with unusual behaviour is studied with hope that an abnormality in the brain will also be found that can be used to explain their behaviour
- E: However, correlation ≠ causation so it can’t be said for certain that the cause of that person’s unusual behaviour
- For example a third variable such as lesions or illness that impacted other areas of the brain could have caused the unusual behaviour
- Since post-mortem exams don’t study live brains compared to brains scanning methods (fMRI, EEG, ERG) it can be problematic to assume that the causation of behaviour is brain abnormality
17
Q
Ways of Studying the Brain (Post-Mortem): Strength is that it provides a detailed examination of the barin
A
- E: Post-mortem examinations can reach areas of the brain like the hippocampus and the hypothalamus compared to brain scanning techniques that can’t view those areas of the brain without losing spatial resolution
- E: This is a major advantage as it allows for researchers to form a more detailed picture of all areas within the brain
- Because of this more research into the brain can be done more easily and provides a major advantage of post-mortem examinations compared to other brain scanning techniques
18
Q
Ways of Studying the Brain (fMRI, EEG and ERG): Strength of fMRI/ Limitation of EEG/ERG is spatial resolution
A
- E: Spatial resolution is the smallest measurement that a scanner can detect
- fMRI scans have a spatial resolution of roughly 1-2mm compared to EEGs and ERGs that have a spatial resolution of roughly 30cm
- E: The spatial resolution of fMRIs is significantly greater than that of EEGs and ERGs
- This means psychologists can determine the activity of different regions in the brain more accurately using fMRIs compared to using EEGs or ERGs and as a result, they can determine the areas of the brain that are active when different behaviours are carried out
19
Q
Ways of Studying the Brain (fMRI, EEG and ERG): Strength of EEGs/ERGs/ Limitation of fMRIs is temporal validity
A
- E: Temporal resolution is how quickly the scanner can detect changes is brain activity
- EEGs and ERGs have a temporal resolution of 1-2 milliseconds compared to fMRIs which have a temporal resolution of 1-4 seconds
- E: This means psychologists can detect changes in brain activity much faster using EEGs and ERGs than using fMRIs and as a result gives a more accurate reading of the timings of change in brain activity
20
Q
Ultradian and Infradian Rhythms: Some research has suggested the menstrual cycle (an infradian rhythm) can be entrained by pheromones of other women
A
- E: McClintlock collected samples of women’s sweat (which contains pheromones) from 9 different women and he then applied it to the upper lips of 20 other women (absolutely gross ik). He found 68% of the sweat recipients had their menstrual cycles become more closely synced to the sweat donors
- E: Since the sweat donors experienced changes to their cycles as a response to an external stimuli suggests the menstrual cycle can be entrained by exogeneous zeitgebers, similarly to circadian rhythms. However the results of this research has been found as challenging to replicate by other researchers which questions the conclusion the menstrual cycle can be entrained by exogenous zeitgebers
21
Q
Ultradian and Infradian Rhythms: Research has helped to understand the sleep cycle (an ultradian rhythm)
A
- E: In 1957, Dement and Kleitmen monitored the sleep of 9 patients using an EEG and found 5 distinct stages of brain activity. In one stages, the patients’ eyes moved rapidly so this was called REM and the other 4 were called NREM. Patients woken during REM sleep were more likely to report dreams than those woken during NREM sleep
- E: This research helped develop what we now know as the sleep cycle. The reports of dreams during REM sleep also helped develop scientific knowledge on the nature of dreams. The use of an EEG increases the accuracy of the study as an EEG takes readings of the brain every millisecond (high temporal resolution). However the use of 9 participants weakens the population validity of the study so it’s hard to generalise the findings to create a general law for everyone’s sleep cycle
22
Q
Ultradian and Infradian Rhythms: Researchers have investigated the impact of the menstrual cycle on sexual behaviour
A
- E: In 1999, Penton-Voak did research and found that women prefer ‘slightly feminised’ faces when looking for a long term partner but had a preference for more masculine faces during ovulation
- The preference is suggested to be a result of physical attributes that are sometimes associated kindness and cooperation when a women is looking for a partner that will care for her children and by finding these genes in a partner, they will be inherited by her children. This shows that infradian rhythms like the menstrual cycle can have a powerful impact on human behaviour. However, this research is socially sensitive as it implies that biology is the only factor that comes into play when women are selecting a partner and that women have little free will when choosing a partner. This could result in stigmatism towards women
