Unit 2: Biological Level of Analysis Session 2

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

2. First things first... • Lab report draft submission • Drafts will be returned with feedback on Friday • Final report due Monday 4th March Unit 2: Biological LOA

3. A recap of session one • There are three principles that define the biological level of analysis • Can you remember any of them? Unit 2: Biological LOA

4. Three Principles of Biological Level of Analysis • There are biological correlates of behaviour • Animal research can provide insight into behaviour • Human behaviouris, to some extent, genetically based Unit 2: Biological LOA

5. How are these principles demonstrated in research? • There are biological correlates of behaviour • Animal research can provide insight into behaviour • Human behaviouris, to some extent, genetically based Unit 2: Biological LOA

6. 1.) There are biological correlates of behaviour Newcomer et al. (1999) • Performed experiment on the role of stress hormone cortisol on verbal declarative memory • Participants listened to a prose paragraph and had to recall is as a test of verbal declarative memory • Group 1 showed worst performance on task • Shows that an increase in cortisol has a negative effect on memory Unit 2: Biological LOA

7. 1.) There are biological correlates of behaviour • Phineas Gage • Iron rod blew threw his skull and he turned into a jerk • Shows that behavior has a physiological basis (his personality changed) • Shows there are biological correlates of behavior (after his frontal lobe was damaged he lost his ability to restrain himself) Unit 2: Biological LOA

8. 2.) Animal Research can provide insight into human behaviour Rozenweig and Bennet (1972) • Performed experiment with rats • Wanted to study role of environmental factors on brain plasticity • Rats spent up to 60 days in their respective environments before being killed • Brains of rats in group 1 showed a thicker layer of neurons in the cortex than group 2 • Shows that brain grows more neurons if stimulated Unit 2: Biological LOA

9. 3.) Human behaviour is, to some extent, genetically based Bouchard et al. (1990) • Minnesota Twin Study • Longitudinal study investigating role of genes in IQ** • Shows a link between genetic inheritance and intelligence but does not rule out the role of environment Unit 2: Biological LOA

10. New terms? What is the difference between monozygotic twins and dzygotic twins? Which one is which? Unit 2: Biological LOA

11. Monozygotic and DzygoticTwins • MZ twins are identical twins • They are from the same egg and share 100% of their genes • DZ twins are fraternal (non-identical) twins • They develop from two separate eggs and share 50% of their genes • They are no more alike than normal siblings • If there is a genetic basis to • behaviour, MZ twins should • show a higher concordance • rate Unit 2: Biological LOA

12. New terms? • Concordance rate? • Longitudinal study? Unit 2: Biological LOA

13. New terms? • Concordance rate: the statistical measure of similarity between twins. A higher % of concordance indicates a bigger similarity • Longitudinal study: A study • that takes place over a long • period of time. Can be weeks, • months or years. Unit 2: Biological LOA

14. Today’s learning outcome • Explain one study of localisation of function of the brain Unit 2: Biological LOA

15. Localisation of Brain Function • Not long after the case of Phineas Gage, two psychologists made some interesting discoveries when looking at stroke victims • Broca (1861) • Wernicke (1874) Unit 2: Biological LOA

16. Paul Broca (1861) • Found that people suffering from damage to their left frontal lobe of the brain were unable to make grammatically complex sentences • Area of the brain eventually came to be called Broca’s area • Broca’s patients had problems producing speech, but were able to understand it • This condition is now know as Broca’s aphasia Unit 2: Biological LOA

17. Paul Broca (1861) • Broca used a case study to support his claims • His most famous patient was a young man named Tan • He was called Tan because that’s the only word he could say • After his death, an autopsy revealed the source of his brain damage and led to the idea that the disability was the result of a specific brain trauma. Unit 2: Biological LOA

18. Carl Wernicke (1874) • First described the area that appears to be crucial for language comprehension • The left posterior superior temporal gyrus • Wernicke’s patients could produce speech, but could not understand it • This condition is known as Wernicke’s aphasia Unit 2: Biological LOA

19. Broca and Wernicke • The research undertaken by Broca and Wernicke provides us with a clear understanding of some of the factors involved in language processing • By carrying out post-mortem studies of people who had suffered from strokes, they came to the conclusion that language processing is localised Unit 2: Biological LOA

20. Localisation? • When a behaviour is localised in the brain, it is possible to trace the origin of a behaviour to a specific part of the brain • Studies in localisation of function led to the desire to map out the brain’s functions • Though localisation does not explain all human behaviour, the mapping out of the brain was an important step forward in brain research Unit 2: Biological LOA

21. The case study of H.M. • Important because it provided evidence that there are different memory systems in the brain • Milner (1957) was first to report case of H.M. and memory function after H.M. Had an operation which removed the hippocampus and adjacent areas in his brain Unit 2: Biological LOA

22. The case study of H.M. • Suffered from epileptic seizures after he fell of his bike aged seven • It was assumed his seizures were related to his accident • He became increasingly incapacitated Unit 2: Biological LOA

23. The case study of H.M. • When he was 27, a neurosurgeon performed experimental surgery to stop the seizures • Tissue from the medial temporal lobe, including the hippocampus, was removed • After the operation H.M. suffered from amnesia • He could recall information acquired in early life, but was unable to form new memories Unit 2: Biological LOA

24. The case study of H.M. • H.M. suffered from anterograde amnesia (failure to store memories that happened AFTER a trauma) • He was unable to remember the faces of new people he met • He could carry out normal conversations, but would not remember people he met after the operation • He could read and re-read the same magazine without realising that he had read them before Unit 2: Biological LOA

25. Corkin et al. (1997) • Did an MRI scan* of H.M.’s brain • Brain imaging was used because it allowed researchers to get a precise image of the brain damage • They were then able to identify where the damage was i.e. the removal of the hippocampus *MRI-Magnetic resonance imaging- a type of brain scanning technique Unit 2: Biological LOA

26. The case study of H.M. • Only his memory was affected by the removal of the hippocampus • His personality remained unchanged and there was no general intellectual impairment Unit 2: Biological LOA

27. What can be learned about localisation of brain from H.M. • The hippocampus and areas around hippocampus play a critical role in converting memories of experiences from short-term to long-term memory • H.M. could retain memories of what happened BEFORE the surgery. This indicates that the hippocampus is a temporary rather than a permanent memory stories • H.M. could learn a few new procedural* memories which indicates that procedural memories are not stored via the hippocampus *procedural memory: memory for skills, actions and actions- “knowing how” Unit 2: Biological LOA

28. What can be learned about localisation of brain from H.M. • The fact that H.M. (and other people with amnesia) had deficits in one part of the memory but not in others is evidence that the brain has several memory systems and that these are supported by distinct brain regions • Shows that memory processes are much more complex than originally believed • Although hippocampus is very important in the storage of new memories it is not the only part of the brain involved in the process Unit 2: Biological LOA

29. Evaluation of case of H.M. Strengths • Surgery was based on assumption that H.M.’s seizures would stop and it was successful in this respect • H.M. participated in research for more than 50 years and participated in many kinds of tests including cognitive tasks, observations and neuroimaging studies Unit 2: Biological LOA

30. Evaluation of case of H.M. Strengths • This longitudinal case study has contributed enormously to knowledge of how memory processes are related to specific areas of the brain: • The hippocampus is important for the forming, organising and retrieval of memories • Procedural memories are not processed by the hippocampus Unit 2: Biological LOA

31. Evaluation of case of H.M. Limitations: Ethical Considerations • Although the surgery stopped the seizures it caused memory problems that had not been anticipated. • Since H.M. was unable to remember all the times he participated in research, it could be argued that it was unethical. However, the findings of the study are very important which justifies it. (remember the ends must justify the means) Unit 2: Biological LOA

32. Evaluation of case of H.M. Limitations • As this was a case study it is questionable whether the results can be generalised to a larger population HOWEVER... • Findings from other case studies of people with brain damage like H.M. tend to support these findings so it may be possible to generalise the findings to some extent. Unit 2: Biological LOA

33. Psychology Journal • One entry pre session in back of book • May just be on topic already covered • Might be new topic/research based • Doesn’t have to be in full sentences, as long as content is clear Today: • Outline the three principles of the biological process noting a demonstration of each Unit 2: Biological LOA