Biopsychology Evaluation Flashcards
Localisation of function evaluation
strength- supported by the Tan’s case study, Broca performed an autopsy on him after his death and found he has a lesion in what is now known as Broca’s area which was the cause of his aphasia (inability to speak) this is a strength as it shows damage in certain regions results in specific deficits
weakness- Lashley removed 10-50% of the cortex in rats that were learning a maze and found that no area was more important than others in learning so learning is not localised but holistic
strength- Peterson used brain scans which showed that Wernicke’s area was active during a listening task and Broca’s area was active during a reading task therefore it shows that different parts of the brain are active for different functions
Hemispherical lateralisation evaluation
strength- Fink used PET scans to show that when pts were asked to identify global elements of an image regions of the right hemisphere were more active but when they were told to focus on the finer detail the left hemisphere was more active, so visual processing is a feature of the connected brain
limitation- Turk shows that the brain can adapt following damage as he discovered a patient who suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere therefore plasticity does not support hemispherical lateralisation
limitation- Lashley removed 10-50% of the cortex in rats that were learning a maze and found that no area was more important than others in learning so learning is not localised but holistic
Split brain studies evaluation
strength- the research is well controlled as it used standardised procedures and controlled extraneous variables -the images only flashed up for 1/10th of a second to ensure there was no time for the info to spread across both sides of the visual field
limitation- the sample is unusual and limited as some pts may have received drug therapy and some may have more disconnection than others so cannot be well matched to a control group
fMRI evaluation
strength- less invasive than other scanning techniques like PET scans
strength- good spatial resolution so brain regions can be investigated more accurately and responses can be pinpointed
limitation- the machines are expensive to buy and maintain as they require trained operators
EEG and ERPs evaluation
strength- they are less invasive than other scanning techniques as radiation or instruments in the brain are not required so they are risk free
strength- cheaper than fMRI scanning and so it is more widely available
strength- high temporal resolution so it records brain activity in real time
Post-mortem examination evaluation
strength- they provide detailed examination of structure that is not possible with scanning techniques so allows for insight into deeper brain regions
limitation- ethical issues as informed consent cannot be gained and the examination is usually done on those with severe psychological deficits who cannot provide fully informed consent anyway
limitation- cannot establish causation as certain brain deficits could have been the result of another illness etc
Plasticity and functional recovery evaluation
strength- Maguire used an MRI scanner to scan the brains of London taxi drivers- they had more grey matter in the posterior hippocampus than a control group which was positively correlated with the amount of time they were a taxi driver
strength- practical applications- it has contributed to the treatment and rehabilitation of brain injury patients
limitation- Ramachandran and Hirstein found that 60-80% of amputees develop phantom limb syndrome and experiences sensations in the missing limb so this is a negative consequence of plasticity
Biological rhythms evaluation
circadian rhythm
strength- practical applications as it provides an understanding of the consequences that occur when they are disrupted e.g. night shift workers
limitation- small sample of case studies e.g. Siffre so findings cannot be generalised to everyone
Infradian rhythms
strength- research is supported by the theory of evolution as it would have been better for women to menstruate together and become pregnant at the same time to allow for orphaned babies to access breast milk and increase their chances of survival
limitation- other factors could cause the menstrual cycle to change such as stress, extreme dieting and exercising
ultradian rhythms
strength- improved understanding of age-related changes in sleep e.g. SWS reduces with age leading to reduced alertness
limitation- researchers ignore individual differences e.g large differences in duration of each sleep stage so normal sleep is difficult to describe
Endogenous pacemakers and the sleep-wake cycle evaluation
strength- Morgan studied hamsters by removing their SCN causing their sleep-wake cycle to completely disappear. After SCN cells were transplanted from other hamsters the sleep-wake cycle was reinstated therefore it shows the SCN is vital in maintaining the sleep-wake cycle
strength- Siffre’s case study is supporting evidence as it showed that without external cues like sunlight Siffre was still able to maintain a relatively normal cycle of 25hrs
strength- practical applications e.g. knowing when drugs work best and being advised to take them at certain times of day
Exogenous zeitgebers evaluation
strength- supporting evidence from Campbell and Murphy who found that shining a light on the back of pts knees shifted the circadian rhythm as light plays a role in our biological clocks
strength- practical applications e.g. Burgess found that exposure to bright light prior to a flight reduced jet lag which has huge benefits for the economy as it increases productivity when returning to work
limitation- Miles studied a man who was blind from birth and despite exposure to social cues his sleep/wake cycle remained abnormal
