4 Ways to STUDY the BRAIN | Biopsychology

there are many ways to find out what is going on in your brain some involve cutting the brain up like this others involve sticking things on your head like this or other ways involve a very large magnet like this but how do they all work and are they any good at telling us what we're thinking hey everyone welcome back to Bear it in mind in this video we're going to explore different ways of studying the brain including post-mortems FM Ariz eegs and erps as we take a look at how each one works we'll critically evaluate them to consider their strengths and limitations at the end of this video there'll be some practice questions of what we cover so that you can check your understanding and link below is a free resource that goes with this video so firstly let's consider post-mortems as a way of studying the brain the word post means after and the word morm means death so after death so a postmortem is an examin ination of a dead body and specifically for our purposes it's the examination of the brain after death now all to frequently when asked in an exam to explain how post-mortems are conducted students typically write they look at the brain when they are dead and yes but there is more to it than that and remember the point of this part of the topic is to understand how looking at the brain after death helps us learn about the brain's involvement in our behaviors so how do we explain post-mortems further three steps number one Behavior firstly they study the individual's Behavior whilst they are alive there may be something particularly abnormal about a person's Behavior which has meant they've been referred to a doctor or psychologist for assessment their strange Behavior could suggest that there might be damage in the brain that is behind these problems two brain next they study their brain after death when the person dies the researchers can examine the brain to look for abnormalities and lesions in the brain importantly their brain is compared to a normal brain in order to identify differences three correlation finally the analysis of the brain allows the researcher to form a correlation between the abnormal behavior of the patient and a particular area of the brain we've considered postmortem research in this topic of bioc pychology already you may remember the research of Paul Brooker PA brocker was sent a patient called Louis Victor lebor when brocker studied lebor he found that regardless of the question asked him he always responded tan brocker carried out different tests to explore the extent of his problems and concluded that he had a problem producing speech when patient tan died brocker himself conducted the postm Martin exam on his brain which revealed a large lesion in the left frontal lobe this discovery provided support for a correlation between an area of the brain the left frontal lobe being responsible for speech production now let's evaluate post-mortems one strength of postmortem is the level of detail they gather about the brain this is because postmortem enable deeper regions of the brain to be investigated compared to brain scanning techniques like eegs which we'll get to shortly post-mortems allow for the examination of the structure of the brain beyond the cerebral cortex that's the outer part of the brain near the skull and it can provide insight into deeper regions of the brain such as the hippocampus areas that are inaccessible for certain brain scanning techniques like eegs however one of the limitations with post-mortems relates to cause and effect this is because post-mortems are forming a correlation between a person's behavior during their life and the damage in their brain the problem is that the behavior such as being unable to produce speech may not have come from that damaged part of the brain the damage in the brain could have been caused by another Factor such as a head injury or an illness another issue with post-mortems as a way of studying the brain relates to ethical issues particularly around inform consent this is the idea that participants in research should be fully informed of the research to which they agree to take part in this case patients would be giving consent to their brain being analyzed through a postmortem when they die for example if we consider the most famous case study in Psychology that of patient hm he suffered from severe Amnesia and so could not form any new long-term memories after his death a postmortem examination of his brain was carried out but to what extent given his condition could he have consented to such procedures therefore other ways of examining the brain that can be done whilst the patient is alive could be argued to be more appropriate particularly from an ethical standpoint throughout the topic of bioc pychology we have considered numerous studies that have scanned the brain using MRIs or fmis so what's the difference an fmri stands for functional magnetic resonance imaging an fmri is different from an MRI because of the word functional an MRI just takes an image of the structure of the brain whereas an fmri measures changes in brain activity whilst participants perform a task well what about the word magnetic what's that all about here's three steps to describe how fmis study the brain and our behavior number one blood flow this way of studying the brain measures blood flow in the brain whilst a person performs a task two oxygen if an area of the brain becomes more active those neurons in the brain use the most energy and require more oxygen three magnetic oxygen is released for use by these active neurons at which point the hemoglobin which carries the oxygen in the blood becomes deoxygenated deoxygenated hemoglobin has a different magnetic quality from oxygenated hemoglobin and that's what the magnet detects for an example of an fmri scan of the brain researchers at Stanford University conducted what they called The Love competition where they invited different people of varying ages to think about the people they most love in the world whilst their brain was being scanned in an fmri machine they were able to identify which individuals loved more deeply in comparison to others by measuring the level of activity in the dopamine serotonin and oxytocin Pathways in the brain linking any motion to a biological process it's a fun video I'll link it below if you've not seen it [Music] before so now let's evaluate fmis to do this we need to understand two key terms temporal resolution and spatial resolution firstly temporal resolution the word temporal refers to time this refers to how quickly the brain scan can detect changes in brain activity secondly spatial resolution the word spatial refers to location this is about how accurately it can show exactly which area of the brain is active it's about how specific the measurement of the location of activity in the brain is one of the main strengths of fmis relates to spatial resolution this is because fmri machines have high spatial resolution of approximately one to2 mm which is significantly greater than the other techniques such as eegs and erps therefore this suggests that fmis can provide more insight into the brain's activity because it offers a more accurate way of studying the brain however one of the limitations of fmis relates to temporal resolution this is because FM I scans have low temporal resolution of around 1 to 4 seconds which is not as good as other techniques for example EGS have a temporal resolution of 1 to 10 milliseconds therefore this undermines the extent to which fmis can tell us about the activity in the brain because this delay makes it harder for psychologists to know accurately when the brain activity started now we move to scanning techniques that use electricity w my finger slipped you may have seen images of people wearing a rather funky looking hat like this some of you watching may have even had an EEG yourself eegs stand for Electro enams breaking that long word into three you can see Electro which is a reference to electricity then there is enph which comes from the word enlon which is Greek for within the head so enph is referring to the brain and the gram refers to recording the activity so it's the measurement of the electrical activity of the brain over time we have seen in a video on neurons and synaptic transmission that the cells of the brain communicate to each other via electrical impulses and it is these electrical impulses that are detected by the EEG this information is then transmitted to a computer which monitors the results here's three steps to describe how EG study the brain and our Behavior one on electrodes this way of studying the brain measures electrical activity of brain cells and neurons through electrodes attached to the scalp information is processed in the brain as electrical activity in the form of action potentials or nerve impulses two intensity and frequency the EEG is able to pick up the size or intensity of electrical activity as well as the frequency or rate of electrical activity three waves electrical signals from the different electrodes are plotted on a graph that provides the data in the form of four different types of waves these are known as Alpha Beta Delta and theta waves the EEG has commonly been used in sleep studies to identify the different stages of sleep for example when you sleep your brain wave activity changes depending on which stage of sleep we are in now you might be thinking there are different stages of sleep well in another video on biological rhythms we'll be exploring this very thing now just before we evaluate eegs we're going to explore our next way of studying the brain event related potentials because the two are connected and then we'll evaluate them [Music] together the brain response to a single stimulus or event is not usually visible in an EEG recording and this is because as we've just seen the EEG records thousands of brain processes that are all happening at the same time it gives a general reading of the brain's activity but what if we wanted to see the brain's response to a specific event well here's where event related potentials come in event related potentials use electrodes to measure very small voltage changes within the brain when patients are presented with a stimulus such as a picture or sound which requires cognitive processing and P recording would look something like this event related potentials divide into two categories waves that occur within the first 100 milliseconds after presentation of the stimulus are known as sensory erps and event related potentials generated after the first 100 milliseconds are known as cognitive erps as they demonstrate some level of thinking and evaluation and processing by the patient as as event related potentials are difficult to identify from all the background activity within the brain the stimulus is presented many many times and are then averaged together so to condense this down to three steps one specific erps study the brain by measuring very small voltage changes in the brain that are triggered by specific events or stimuli two averaged to establish a specific response to a specific event or stimulus requires many presentations of the stimulus and these responses are then averaged together three filtered out using a statistical averaging technique all background brain activity from the original EEG recording is filtered out so that the event related potential the response to the specific event is left now I know that this is the most complicated of the four ways of studying the brain so I'll give you an example of an Erp being used in a study this is in more depth than you need to know for your a level exam so this is just for your own understanding and interest feel free to skip to the next part using the time stamps below if you want here's a study into depression that used erps will those who are suffering with depression respond differently to certain stimuli compared to a control group as a reminder an Erp look something like this waves that occur within the first 100 milliseconds after presentation of the stimulus are known as sensory erps and waves that occur after the first 100 milliseconds are known as cognitive erps P3 is often of interest because it's a cognitive Erp it shows the person processing and thinking in this study they found that at P3 depressed patients had erps that were less intense and were delayed in their response more time passed before their brain responded in other words they were slow lower in their responses to the stimuli presented to them than the control [Music] group so let's now evaluate both eegs and erps as ways of studying the brain firstly one strength of eegs is that they are effective tools for diagnosing certain brain disorders for example as we have seen eegs can be used to monitor stages of sleep and people can have their brain monitored whilst they are sleeping to diagnose any sleep problems additionally eegs are successfully used in diagnosing epilepsy as seizures are reflected in abnormal brainwave patterns a strength of both EEG and erps is that they are cheaper than fmis for example at the time of recording this video the cost of an EEG machine is anywhere between $1,000 and $225,000 whereas an fmri machine costs anywhere between half a million and $3 million this this means that eegs and erps are more accessible for a wider range of people and further means that larger sample sizes from studies can be used to draw conclusions about the brain's activity another strength of EGS and erps relates to temporal resolution as a reminder this refers to how quickly the brain scan can detect changes in brain activity this is because eegs have high temporal resolution as they take readings of the electrical activity in the brain every Mill second this means it can record the brain's activity in real time as compared to having to wait 1 to 4 seconds for an image of the brain's activity like an fmri therefore it could be argued that eegs provide an accurate measurement of when brain activity is occurring however as you can probably guess the limitation of eegs and erps relates to spatial resolution spatial resolution is about how accurately it can show exactly which area of the brain is active this is because EGS have low spatial resolution as they only detect the general activity of the cerebral cortex the outer part of the brain and not specific areas eegs are unable to provide information on what is happening in the deeper regions of the brain such as the hippocampus making this technique limited compared to fmis here's a summary table of what we've covered so far in this video that may be helpful for [Music] you now just before we get to the test yourself questions the next video in the bioc pychology topic is all about sleep and the biological clock that you have inside you that controls when you wake up and when you fall asleep you'll find that video linked below if you want to watch that but now it's time to check your understanding of what we've covered in this video I'll present one question at a time you can pause the video to answer it yourself first and then press play again to reveal the answer [Music] [Music] [Music] [Music] I hope you found this video helpful and we'll see you in the next one

Channel: Bear it in MIND

Views: 2,328

Keywords: aqa alevel psychology, revision, biopsychology aqa a level psychology, ways of studying the brain psychology a level, post-mortem, fMRI, functional magentic resonance imaging, EEG, electroencephalogram, ERP, Event related potentials, temporal resolution fMRI, spatial resolution fMRI, spatial resolution EEG, temporal resolution EEG, Biopsychology revision, aqa psychology paper 2 revision

Id: Xye1dDY5RYw

Length: 18min 29sec (1109 seconds)

Published: Wed Jan 31 2024