Unit 2: Biological Level of Analysis Session 10

1. Unit 2:Biological Level of AnalysisSession 10 ‘All that is psychological is first physiological’

2. Today’s learning outcome Discuss the use of brain imaging technologies in investigating the relationship between biological factors and behaviour.

3. Don’t forget to take notes- this session will help you to complete some of your holiday assignment!

4. The use of technology in brain research • Modern technology is now extensively used in neuropsychology • Allows researchers to: • Study the active brain • See where specific brain processes take place • Enables localisation of function in LIVING brain

5. Invasive techniques in brain research • Animals are still extensively used in brain research as they allow psychologists to study specific biological correlates of behaviour using invasive techniques* • Many early experiments involve invasive techniques *often involves removing (ablation) or scarring (lesioning) brain tissue in order to study behavioural changes i.e. Study behaviour before and after ablation/lesioning

6. Hetherington and Ranson (1942) • Classic study involving invasive technique • Lesioned part of brain called ventromedial hypothalamus in rats • Rats increased food intake dramatically, and often doubled in weight • Led researchers to believe that hypothalamus acted as a brake on eating • More recent research, however, has argued that although hypothalamus plays a role in regulation of hunger, its exact role is not yet understood.

7. The use of invasive techniques? So what’s the problem???

8. Got it in the bag yet? Can Do Can’t Do With Participants

9. Ethical issues with invasive techniques • Invasive techniques raise serious ethical concerns • In cases of lesioning and ablation, the potential harm to the animal cannot be determined • In addition, any damage caused cannot be reversed • Finally there is the question of causing pain to animals

10. Modern brain imaging technologies • Modern researchers use brain imaging techniques to investigate relationship between behaviour and brain structures 1. Electroencephalogram (EEG) 2. Positron Emission Topography (PET) 3. Magnetic Resonance Imaging (MRI) 4. Functional Magnetic Resonance Imaging (fMRI)

11. Electroencephalogram (EEG) • Imageoften thought of as ‘brain waves’ • When neurons transport information through the brain, they have an electrical charge • Registers patterns of voltage change in the brain • Psychologists have gained better understanding of behaviours as diverse as sleep, emotions & epilepsy • Provides limited information- cannot reveal what’s happening in deeper brain regions; nor can it show actual functioning of brain

12. Positron Emission Topography (PET) • Monitors glucose metabolism in brain • Patient injected with harmless dose of radioactive glucose • Radioactive particles detected by PET scanner • Used to diagnose abnormalities like tumors, Alzheimer’s, schizophrenia etc

13. Magnetic Resonance Imaging (MRI) • Uses a magnetic field and radio waves to create detailed images of the body.  • Gives detailed pictures of internal structures in brain

14. Ashtari et al (2009) • Used MRI to investigate whether substance abuse (marijuana) can damage developing brain of young adults • Scan indicated that there were brain abnormalities in frontal, parietal and temporal regions in brain of marijuana users • Development of white matter (myelin*) was affected could explain slow information processing in brain • Concluded that early marijuana use can affect brain development but as study gives correlational data more research is needed *Remember: Myelin sheath covers neuron and helps to speed up neurotransmission

15. Where have we already seen use of MRI? Case study of H.M. • Corkin et al (1997) did MRI scan of H.M’s brain which allowed for precise picture of brain damage. Confirmed that hippocampus was missing- able to link to memory.

16. Strengths of Magnetic Resonance Imaging • MRI scans show how blood flows in brain and can be used to identify problems with blood circulation. Can be used for early detection of Alzheimer’s • Safe to use as no radioactive material is used

17. Limitations of Magnetic Resonance Imaging • Scanner not a natural environment for cognition- question of ecological validity • Very expensive • Movement may affect images • Cannot say anything about cause and effect relationships, only provide correlational data

18. Can MRI scans catch psychopaths? Watch the video

19. Functional Magnetic Resonance Imaging (fMRI) • Scanner measures changes in blood flow in active brain • Blood flow associated with use of oxygen and neural activity during information processing • When participants are asked to perform a task, scientists can observe the part of the brain that corresponds with that function • Use increased vastly over past ten years and now widely used by cognitive neuroscientists

20. Harris and Fiske (2006) • Study aimed to find biological correlates of stereotypes and prejudice • Studied brain processes as a response to extreme outgroups • Scanned students’ while they were watching pictures of different humans or objects • Predicted that prefrontal cortex would be active when students looked at humans but not objects • This was found EXCEPT when students looked at pictures of extreme outgroups e.g. Homeless and addicts • Brain regions linked to disgust were then activated and there was no activity in prefrontal cortex • Concluded this indicated a dehumanisation of outgroups. These groups apparently viewed as ‘disgusting objects’ rather than people

21. Where have we seen fMRI before? Baumgartner et al (2008) Oxytocin and Trust • fMRI scans carried out on participants • In oxytocin group cans showed decreases in responses in amygdala (involved in emotional processing) and caudate nucleus (involved in learning to trust) • Explanation for behaviour in trust game

22. Strengths of Functional Magnetic Resonance Imaging • One of most frequently used technologies in biopsychological research today • Shows actual brain activity and indicates which areas of brain are active • Scans have higher resolution than PET scans and are easier to carry out • Does not use radioactive substances • Can record activity in all regions of brain

23. fMRI to fight depression? Watch the video

24. Limitations of Functional Magnetic Resonance Imaging (fMRI) • Focus mostly on localised functioning in brain and does not take into account the distributed nature of processing in neural networks • Results are correlational so not possible to establish cause and effect relationships • Scanner not a natural environment for cognition- question of ecological validity • Brain areas activate for different reasons- e.g. Just because amygdala lights up does not necessarily mean fear is the response being observed

25. Journal Entry: TOK and Ethics • The use of PET and fMRI scans has helped psychologists to identify brain patterns for dysfunctional behaviours. There is a certain pattern for people with schizophrenia, alcoholism, depression, and other disorders • These patterns are present, even if person does not show any symptoms of disorder. 1. Do you think doctors should scan patients to let them know if they have a predisposition for a mental illness? What effect do you think this would have on the patient? 2. Could this technology be misused? Does the potential abuse of technology and knowledge mean that it should not be pursued.