Ways of studying the brain

Exam paper mark scheme

Biopsychology specification: still to cover The divisions of the nervous system: central and peripheral (somatic and autonomic). The structure and function of sensory, relay and motor neurons. The process of synaptic transmission, including reference to neurotransmitters, excitation and inhibition. The function of the endocrine system: glands and hormones. The fight or flight response including the role of adrenaline. Localisation of function in the brain and hemispheric lateralisation: motor, somatosensory, visual, auditory and language centres; Broca’s and Wernicke’s areas, split brain research. Plasticity and functional recovery of the brain after trauma. Ways of studying the brain: scanning techniques, including functional magnetic resonance imaging (fMRI); electroencephalogram (EEGs) and event-related potentials (ERPs); post-mortem examinations. Biological rhythms: circadian, infradian and ultradian and the difference between these rhythms. The effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle. This week: Brain scanning techniques Split brain Research methods

Objectives To be able to… Outline and evaluate ways of studying the brain; including functional magnetic resonance imaging (fMRI); electroencephalogram (EEGs) and event-related potentials (ERPs); post-mortem examinations. Apply this knowledge to two exam questions comparing the ways of studying the brain.

Outline and evaluate one study that investigates brain plasticity (6) Starter Outline and evaluate one study that investigates brain plasticity (6) Optional: Key words to help with your evaluation Objective left handed male participants Highly controlled scientific quasi experimental

Model Answer One study investigating brain plasticity is Maguire et al (2000). In this study Maguire examined the brains of London taxi drivers using MRI scans. She compared the brains with a group of matched controls. Maguire found that the hippocampi of the taxi drivers differed from that of the controls as their posterior hippocampus was larger. It is thought that this is because learning the ‘knowledge’ causes reorganisation of the brain and the area responsible for navigation and spatial skills becomes larger. This study was a highly controlled investigation that used scientific methods to examine the brain. The use of MRI scans allowed for easy comparison between the groups and provided objective measurements of the hippocampus. In the study Maguire only used male participants. This means that the results cannot be generalised to female taxi drivers and so is an unrepresentative sample. We can also argue that, because the sample were all left handed, we cannot generalise the results to left handed taxi drivers as the organisation of their brains may be different. A final point is that although Maguire used scientific methods to examine the brain, the research method was quasi experimental. This is because Maguire could not randomly allocate the participants to the two groups. This lack of control over the independent variable means that other factors (rather than being a taxi driver) may have influenced the results.

Starter: Picture Quiz In pairs…any ideas? Write down everything you know about these techniques

Ways of studying the brain You are a specialist on one of the ways of studying the brain. The other members of the group need to know how the technique works, the advantages and disadvantages of the technique. They have been given specific questions to ask regarding the brain scanning technique to elicit as much information as possible. You will have 10 minutes to look over your technique from your pack/textbook (as well as the additional notes provided by your teacher). Each specialist will have to answer the questions posed about their brain scanning technique in order to help their group members fill in their grid Each group member will have to speak clearly and coherently in order to give the other members time to complete their grid For those in the group that feel like they would like a challenge in explaining a technique select: FMRI or ERP

So what have we learned? Add any new additional information that you have learnt today about each technique

Check understanding (AO2) Apply it A psychologist wants to investigate: Brain waves triggered by being tickled on the hand Brain waves during different stages of sleep (REM-dream sleep and N-REM) Difference in frontal lobe activity of psychopaths and normal controls Structure of the brain of a girl called Genie (who was locked in a room with no contact for the first 8 years of her life) and has now passed away. Which would be the best method of investigation for each of these examples? Explain why this method is more suitable for this particular example, than the other methods? 1. ERP 2. EEG 3 FMRI 4. Post Mortem

Making the big decisions: Apply it AO2 Tip! Research the method of PET scans (positron-emission tomography). This may be appropriate for one or more of the cases below. Decide on the best method for studying the brain from each of the following cases. Justify your decisions. Describe any problems you may run into by using your chosen method. Use all of your resources from today to help you

If you want to challenge yourself select the case studies in red A. Your patient, Henry, has an incredibly rare brain injury which means that he struggles to form new memories. Interestingly, he can still learn new skills but he has no recollection of being taught. He is 87 years old. B. You have a 23-year-old patient who you suspect is epileptic. They have a fear of small spaces but have lots of spare time as they do not work. C. You are a researcher interested in how the brain reacts to very specific reasoning tasks. In particular, the brain’s initial response to a visual puzzle or an optical illusion. You need your patients to be able to sit down and study images in a reasonably realistic setting. D. You are a researcher who is interested in where we store memories in our brain. You know it is the hippocampus but you need a detailed and specific view to determine whether positive and negative memories go to the same part of the hippocampus. You’ll need to carry out your research on children and seriously ill hospital patients. E. You are interested in discovering where language is produced in the brain because you suspect that language production and language comprehension are controlled by different areas of the brain. You have 10 participants, and a budget of £100,000 F. You are interested in the areas of the brain responsible for emotional processing in people with ADHD, who find it difficult to stay still for prolonged periods. You have a budget of £3,000. If you want to challenge yourself select the case studies in red

Check understanding (AO1) Challenge: Match as many of the remaining three to their correct method of studying the brain as you now can This is how it appears in one of the specimen papers:

Exam focus The electroencephalogram (EEG) and event-related potentials (ERPs) both involve recording the electrical activity of the brain. Outline one difference between the EEG and ERPs. (2 marks) Extension: outline one difference between EEG/ERP and FMRI

Model answer EEG is as recording of general brain activity usually linked to states such as sleep and arousal, whilst ERP’s are elicited by specific stimuli presented to the participant

Exam focus Discuss EEG and FMRI as brain scanning techniques to studying the brain (8 marks) Read the modal answer to question 2. Highlight A01, A03, evidence of signposting, evidence of PEL/ PEEL Extension: compare your answer to the modal answer. Add, in green, any improvements you want to make to your own answer.

Exam focus Describe and evaluate brain scanning techniques as a way of investigating the brain (16) If you want to challenge yourself, plan without notes

Plenary A researcher used an fMRI scan to investigate whether different types of long-term memories are located in different parts of the brain. Participants were asked to think about family holidays they had been on as a child and their brain activity was recorded. The same participants were then asked to mentally ‘list’ European capital cities and their brain activity was again recorded to see if there was a difference. What type of experimental design is being used in this study? (1 mark) What are the two types of long term memory being described? (2 marks) Name 1 area of the brain we would expect to be active when thinking about family holidays and 1 area for capital cities (2 marks) Who conducted a study of a similar nature to this? (1 mark) This could be described as a laboratory experiment. Briefly discuss the Strengths of a lab experiment with reference to the investigation above (2 marks)

Plenary Repeated measures Episodic (holiday), semantic (facts) episodic- hippocampus. Semantic- frontal and temporal lobes. Tulving Strengths- highly controlled, which means we can clearly identify the area of the brain that is active during certain tasks. More able to establish cause and effect. Extension: what are the weaknesses of a lab experiment

Check understanding (AO2) Apply it! Shaun is worried about his sleeping patterns and he wants to know how he will be assessed. He is terrified of enclosed spaces and any invasive medical procedures. Advise him on which method would be most appropriate for him, and calm him down by explaining what will happen during his assessment. However, you must be honest with him and include any risks which may be involved.