Biopsychology methods of studying the brain Flashcards
what is post morterm examination
Research study a persons unique abnormal behaviour whilst they are alive after death they analyse the structure of the brain areas that are damaged after post mortem examination and correlate brain damage with the abnormal behaviour if no data on these brain structures before the person dies it is compared against a healthy brain to show abnormalities.
what is the strength of post mortem relating to precision
it allows for a more detailed examination of anatomical and neurochemical features compared to fmri where you cannot expect to get close to the brain and really examine the details wheras in post mortem examination you can physically asses the brain parts so give more precise info in which parts of the brain is involved in paryicular behaviours.
what is strength of post mortem scientific credibility
strength is that brain post mortem examination has helped add scientific credibility in the past it provides evidence which is crucuial in building first understanding of key brain processes. Paul broca used post mortem examination and established a link between language and the brain area before neuroimaging was developed impinning in giving hypothesis for further study which adds scientific credibility before neuroimaging development.
what is a weakness of post mortem the cause and effect
One weakness of post-mortem examination is the data gathered after the death limited data and its retrospective so you are unable to follow up and further investigate other areas of damage in addition we don’t know whether the damage caused the abnormal behaviour or the brain damage occurred to brain decay after death
weakness of post . ortem related to smaple size
Another weakness is that it is generally a small sample size as it is often difficult to find patients with certain brain abnormalities for who we have data on therefore we cannot apply the findings to the population.
what is an fmri
Uses magnetic field and radio waves to measure the change in blood flow present in the form of neural activity. The active brain requires energy so oxygen is carried to the brain through haemoglobin and used to create energy and water. The fmri detect the water molecules and allows you to infer neural activity. Activity is presented as 3d activation to map the active areas are highlighted during task highlighted yellow and red. To investigate the brain activity we compare the experimental task activity to a baseline task and visualise the difference.
what is a strength of fmri safety
is safer than other scans as it avoids the use of radiation , unlike PET scans it also is risk free and non invasive so can be used frequently and still provide a clear quality of the brain activity.
what is a strength of fmri during tasks
that it helps understand a change in brain activity during tasks in comparison to mri and post mortem which only give structural information only. Fmri can measure deeper reigion of the brain fro example the amyglada whereas eeg and erp only measure areas that are near the surface and gives a more complete picture of activity in brain.
what is a weakness in terms of temporal resolution
is that there is poor temporal resolution, in the brain activity changes very quickly change in blood flow detected by fmri are very slow thus fmri cannot detect quick changes and is poor at detecting when activity happens known as poor temporal resolution vs eeg it measure exactly when activity takes place . so the fmri measure changes in blood much slower than change in neural activity. Quicker changes of activity in the brain are unlikely to be detected by fmri so not effective for identifying when brain activity occurs.
what weakness sample size
weakness is the reduced sample size due to cost. Compared to other methods it is very expensive so we must use a small sample size in order to reduce the cost and therefore difficult to generalise the findings to target population so decreasing the validity of the findings.
what is an eeg
Measures electrical activity in the brain electrodes are placed in the scalp detects small electrical changes resulting from neural activity the number of electrodes are based on the area which is being researched the wider the area the more electrodes are used, records signals from thousands of neurons directly under the area of the electrodes and provide a measure of general activity in the brain , there are four patterns alpha waves which are presented in relaxed and retiring state, beta waves when awake and mentally active, theta waves light or drowsy seleep and finally delta waves patterns seen when in deep sleep
what is the strength eegpractical application
there are practical applications which has helped diagnose and research disorders such as epilepsy as it measure random burst of electrical brain activity and it also helps woth further research on sleep cycles as it shows different brain waves in different stages of sleep.
what is a strength eeghigh temporal resolution
There is high temporal resolution as unlike fmri eeg picks up on quick changes in neural activity that happen in each millisecond when electrical impulses happen there is a very precise temporal resolution as you are able to identify when neural activity occurs
what is a strength population size of eeg
Cheaper than FMRI as eeg is much more cheaper than FMRI so a lot more people can be used as samples so a larger sample size so we can generalise to the larger population increasing validity of the findings
what is a weakness eeg the spatial
the low spatial resolution information from the eeg in general as it combines activity from lots of locations underneath the electrodes and therefore has low spatial resolution as it is doesn’t pinpoint exactly where neural activity is taking place whereas FMRI can.
