A2 Science In Society 3.3 Teacher Notes Introduction This activity explores one way in which fMRI has been used to investigate the effect of racism on brain functioning. Students have to read one scientific paper and three articles that describe or discuss the work and its conclusions. This allows students to learn about a controversial application of fMRI and to practice for the Unit 4 exam. The activity As students will have probably already done some practice case studies in earlier topics they might be given the articles to read for homework a week before the class activity. However some groups may need to go through the scientific paper in class. It is long and would have been edited for an actual exam question. Sources Source A - Bias taxes brain, research finds Gareth Cooke Boston Globe November 17 2003 http://www.boston.com/news/nation/articles/2003/11/17/bias_taxes_brain_research_finds/ Source B - Excerpt from radio feature “Racial Bias on the Brain”- All in the Mind, ABC Radio National, Australian Broadcasting Corporation, 2003. See student sheets. Source C – Inside the Mind of a racist David Adam Guardian November 17 2003 http://www.guardian.co.uk/uk/2003/nov/17/science.highereducation Source D - An fMRI investigation of the impact of interracial contact on executive function. Jennifer A Richeson et al. Nature Neuroscience Volume 6 Number 12 December 2003. http://groups.psych.northwestern.edu/spcl/documents/fmri_000.pdf Suggested answers to Questions Questions 01 and 02 are about Sources A and C 01 The two articles describe the use of FMRI to detect brain activity that is due to racism. What do they suggest is actually going on in the brain when activity is detected.? Give quotes from each to answer this question. “they struggle not to say or do anything offensive” ‘“executive control” conscious effort to direct thinking’ “concentrating on not doing or saying anything offensive” “The people are working hard to negotiate the interaction” (3 marks) Page 1 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets 02 Both journalists give quotes from other experts in the field. Give examples to show how they have used these quotes to shape the overall message of the significance of the research in their article. Source A gives more confident interpretation than source C A only one quote from other expert/Gabrieli praising research Gabrieli quoted as very simplistic acceptance of findings Source C quotes several experts/ Gehring /Turner /Nature editorial Raise far more doubts about findings and about significance e.g. Phillips quote (3 marks) 03 The earlier research described above found a correlation between racial bias and performance on the Stroop test. The researchers came up with a hypothesis to explain the correlation and designed the research reported in this case study to test their hypothesis. Explain the hypothesis being tested. The hypothesis includes the following points: Interracial interaction for a person with racial bias requires executive control Executive control, also called executive function or executive attention or response inhibition, can be temporarily exhausted. This is called resource depletion One task requiring this part of the brain tires it out e.g. interracial interaction Therefore another task immediately afterwards requiring the same brain function will not be done as well e.g. Stroop test. To test hypothesis it is necessary to show that executive function part of brain actually working during interracial contact. (HSW Cc Cd Ce) (4 marks) 04 Use the information in the third paragraph of the paper Source D that starts “Given the focus of the proposed resource depletion model”. Very briefly outline what is known about the function of the two brain regions DLPFC and ACC, chosen for investigation in the fMRI. Both part of complex circuit of brain structures that support executive function Part of DLPFC has been associated with response inhibition ACC monitors for conditions in which control may be necessary(SE Ka Kb) (2 marks) 05 How do the scientists writing this paper, Source D, acknowledge their sources of information about these brain regions? references given in this paper to many other published papers (HSW Ec) (2 marks) The evidence presented in source D is partly in the form of three scatterplots, Figure 2 a & b and Figure 3. These plot ‘mean percentage signal change’ against IAT or Stroop scores. Questions 06 – 08 are about these Figures. 06 What two sets of signals from the fMRI are used to calculate this percentage signal change? Use the results section of the paper. When seeing no faces, baseline When seeing images of black faces Change is difference between the two as a percentage of baseline (2 marks) Page 2 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets 07 Which of the two brain regions investigated shows the greater correlation between signal change and IAT score in Figure 2? Give the reasons for your choice. DLPFC (b) correlation coefficient r is 0.53 as opposed to 0.44 for ACC (a) (HSW Bb) (2 marks) 08 In plotting graphs the two variables are called the dependent variable and the independent variable. The dependent variable may be caused by the independent variable. It is conventional to put the independent variable on the x-axis. In this paper percentage signal change is treated as a dependent in Figure 2 and an independent variable in Figure 3. Explain how this relates to the theory being tested. Racial bias( independent variable), is expected to cause greater brain activity in control regions investigated, the need for control to prevent the subject showing racist behaviour Brain activity in these executive regions,(independent variable), leads to depletion which is assumed to cause poor Stroop score (HSW Bb Bc) (4 marks) Questions 09 and 10 are about the Implicit Association Test, IAT. 09 Explain how measures of time taken to complete the task can be converted into a measure of racial bias, using any of the sources you find helpful. The test asks participants to pair words – either positive or negative - with first names typical of either white or black people. The response time is measured. Delay in pairing positive words with ‘black’ names indicates racial bias. The method only tests reactions to words, not overt racism or racist behaviour. (2 marks) 10 Using Source B explain how it is possible to provide an alternative explanation for the IAT data. High IAT scores could be a reflection of positive attitudes to one’s own racial group rather than negative attitudes to another (or a bit of both). People might associate positive words more with their own group simply because they are more familiar with them and not because they are biased against another group. (HSW Cf) (3 marks) 11 Do you think the research described in these sources shows that fMRI could be used to detect whether someone has racist views? Explain your answer. No, the regions studied are used for many mental tasks. Activity in these regions could be explained by other reactions to the fMRI testing The effects shown are very small The sample size is very small (HSW Bf Cf) (2 marks) 12 Do you think it would desirable to have such a test, if it were 95% reliable? Ethics Thought processes should be private Main explanation is that subjects are attempting to suppress racist thoughts, not to act on them Only a public issue when racist actions follow Data 95% reliable would still mean a large number of false positives if it were widely used fMRI results depend on IAT test, why not use IAT if such a test were ever needed. (HSW Hh) (3 marks) Page 3 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets Questions 13 and 14 are about the quote in Source A where the lead researcher, Jennifer Richeson is quoted as saying that ‘The work …paints a dispiriting portrait of the state of the nation's race relations’ 13 Give two reasons why this claim is not justified by the research evidence. The research is based on a small sample of white students in one university, but the findings are extrapolated by Richeson to ‘the nation’. To make this claim valid, the sample would need to use a representative sample of people from across the USA. Racist attitudes in an IAT test is not the same thing as poor race relations. (HSW Bf) (2 marks) 14 Suggest why Richeson may have made this claim to the journalist (assuming she was not misquoted). Richeson might want to emphasise the importance of her research with a view to improving her profile or attracting further funding. Richeson might have a low opinion of the nation’s racial bias for reasons unrelated to this research and is using her research to promote her views. (Ef Fd) (2 marks) 36 marks Page 4 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets Section B 15 This case study includes examples of two different ways of communicating new science findings, popular journalism and the scientific paper. Sources A and C make quite dramatic and probably sometimes exaggerated claims about this research. They go beyond the original scientific paper in some ways to attract interest and to discuss implications. Few members of the public are likely to bother to read the original paper. Are the journalists being irresponsible or fulfilling an important role in informing public debate about science? Are some popular articles more effective than others? Discuss the advantages and disadvantages of the two different ways of communicating new science findings, using examples from sources in this case study. (12 marks) Use level descriptors Examples of points that might be included in a good answer. HSW specification ideas in brackets Original paper peer reviewed (Eb) conclusions supported by evidence (Eb) references experimental details very hard to understand need to be expert in field newspapers and radio allows wider audience (Fb) captures interest explains in easier language allows inclusion of alternative points of view - Sources B & C include alternative interpretations, although A does not (Ec) brings research that may need ethical debate to public attention (Hh) headlines and first paragraph often exaggerate - Source C headline “possibility that police recruits could be screened for bias” (Fc) uses speculation at end of paper as firm conclusions “results suggest that harbouring racial bias may be maladaptive to optimal cognitive functioning” becomes “racism can make you stupid” often quote scientists themselves making claims that go beyond evidence e.g. Richeson quote in 4(a) (Fc) often do not inform audience as to reliability, e.g. sample size - no mention in Source A (Bf) Page 5 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets A2 Science in Society - Level descriptors for 12 mark questions The marking scheme for this section includes an overall assessment for the quality of written communication. There are no discrete marks for the assessment of written communication but quality of written communication will be one of the criteria used to assign the answer to one of four levels. Marks are assigned according to level descriptors. Candidates would be expected to achieve at least 3 of the 6 descriptors to be awarded marks at that level. Not all descriptors are relevant to each answer. The marks awarded within the range depend on the extent to which candidates have met the criteria for that range and also on guidance relevant to the specific question. level of response good level 4 descriptors: competent level 3 clear exposition of science explanations relevant to the issue; appropriate and effective use of the relevant ideas about how science works; good overall grasp of the range and nature of the issue(s); interprets arguments presented, recognising evidence, claim and counterclaim; writes well structured argument using a range of evidence to reach a reliable conclusion, includes counter-argument; fluency and accuracy of expression, with only minor errors of grammar, punctuation or spelling. good attempt at exposition of science explanations; use of some relevant ideas about how science works; general grasp of the range and nature of issue(s); interprets arguments presented, recognising some of the main components writes structured argument using some evidence to reach a conclusion; accuracy of expression, with some errors of grammar punctuation or spelling exposition of science explanation minimal or inaccurate minimal use of ideas about how science works; grasp of some features of the issue(s); interprets only part of arguments presented arguments presented but with weak structure and/or minimal evidence accuracy of expression, but with serious errors of grammar punctuation or spelling limited level 2 inadequate level 1 exposition of science explanation confused use of ideas about how science works absent or wrong appears not to understand the issue; cannot interpret the argument presented argument presented as just a claim with no structure or evidence expression unclear with serious errors of grammar punctuation or spelling incorrect or no response Total 0 mark range 10-12 7-9 4-6 1-3 0 12 December 2009 Page 6 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets Introduction This activity explores one way in which fMRI has been used to investigate the effect of racism on brain functioning. You have to read one scientific paper and three articles that describe or discuss the work and its conclusions. This allows you to learn about a controversial application of fMRI and to practice for the Unit 4 exam. Sources Source A - Bias taxes brain, research finds Gareth Cooke Boston Globe November 17 2003 http://www.boston.com/news/nation/articles/2003/11/17/bias_taxes_brain_research_finds/ Source B – Excerpt from radio feature “Racial Bias on the Brain”- All in the Mind, ABC Radio National, Australian Broadcasting Corporation, 2003. See below. Source C – Inside the Mind of a racist David Adam Guardian November 17 2003 http://www.guardian.co.uk/uk/2003/nov/17/science.highereducation Source D - An fMRI investigation of the impact of interracial contact on executive function. Jennifer A Richeson et al. Nature Neuroscience Volume 6 Number 12 December 2003. http://groups.psych.northwestern.edu/spcl/documents/fmri_000.pdf Source B Excerpt from radio feature “Racial Bias on the Brain”http://www.abc.net.au/rn/allinthemind/stories/2003/997984.htm All in the Mind, ABC Radio National, Australian Broadcasting Corporation, 2003 Natasha Mitchell: Can I come to Andy Karpinksi from Temple University, you’re also a social psychologist who researches human attitudes, and the way in which psychology might indirectly measure them - questions like race, prejudice, discrimination. You and your colleagues have some problems with this study because you’re not confident that what was being measured in the first place was racial bias or personal prejudice. Why not? Andy Karpinksi: We don’t have a problem with the term ‘racial bias’. It’s the link between the term ‘racial bias’ and ‘prejudice’ - that there are multiple reasons why a racial bias might emerge, and some of those may have to do with personal prejudice and some of them may not have to do with personal prejudice. For example, in many of the news headlines we go into this article, the word ‘prejudice’ has appeared prominently in those titles and so people immediately go from ‘racial bias’ to ‘prejudice’. That’s not clear that that’s a link that should be made in this study. Natasha Mitchell: Let’s just explain that a bit more, what you’re indicating there is that this study when they did that original test with the group of white students, they might have been picking up a bias but it might not necessarily indicate how that might translate into a behaviour. Page 7 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets Andy Karpinksi: Prejudice usually is defined as a negative attitude towards some group, and in this racial bias measure it’s measuring the extent to which you have positive or negative associations with whites kind of at the same time. So if you have a lot of positive associations with whites you could end up showing a racial bias, and that’s a different take on how you would interpret this measure as opposed to a personal prejudice interpretation. Natasha Mitchell: I think we’d better give people a bit of picture of what this measure is. It’s actually a very popular technique used by psychologists called an Implicit Association test (IAT), but what does that mean? Andy Karpinksi: Well, it tries to measure the implicit or automatic associations you have between two attitude objects. It’s a very flexible measure, in this case it’s been used to measure the associations that you have whites and blacks. And the way it works is that at one stage you see positive words, negative words, white names, black names - and you have to categorise positive words and white faces, white names on one key together; and negative words and black faces or names on one key together. And the logic behind that stage is that if you have a lot of positive associations with whites and/or negative associations with blacks that task ought to be very easy for you. Later on the categorisation is switched. So then you’re categorising positive words and black faces on one key, negative words and white faces on one key. So if you have a lot of positive associations with blacks and/or negative associations with whites the task ought to be easy. So by looking at the difference between those two, I can get a measure of your racial bias. However that measure could be measuring differences in your associations with whites, differences in your associations with blacks, or some combination of those two. It’s controversial because there are multiple interpretations of it, so it hasn’t clearly been established that this measure is a measure of your personal attitudes. To the extent that a person has a stressful interaction with an individual, is unfamiliar with African Americans or blacks for any reason or uncomfortable with them for any reason, you might find that those individuals show a racial bias and also try and control their thoughts in an interracial interaction, regardless of whether they endorse negative beliefs about that group. Page 8 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets Section A Read the information below and all the sources before you begin answering the questions The earlier research The research in this case study follows on from earlier work by some of the same team. In the earlier work they tested subjects for racial bias using the Implicit Association Test, IAT. They then organised interaction between these subjects and a black researcher. This was immediately followed by a test of cognitive ability, the Stroop test. In the Stroop test participants are asked to state the colour of printed words. Some words are compatible (for example the word ‘red’ written in red letters), and others are incompatible, (for example the word ‘red’ written in blue letters). An incompatible word requires considerable mental effort to restrain the initial response, in this example, red, and to press the correct response, blue, leading to a delay in response time. The researchers found a strong correlation between racial bias as measured on the IAT test and poor performance on the Stroop test, done immediately after interaction between white students and a black researcher. There is thus a need for a hypothesis to explain why, although the Stroop test has nothing to do with race, racial bias should affect performance on the test under these circumstances. The research reported in these sources is about the use of fMRI to test a hypothesis which may explain this correlation. Questions 01 and 02 are about Sources A and C 01 The two articles describe the use of fMRI to detect brain activity that is due to racist bias. What sort of thinking do they suggest is actually going on in the brain when activity is detected? Give quotes from each article to answer this question. (3 marks) 02 Both journalists give quotes from other experts in the field. Discuss how they have used these quotes to shape the overall message of the significance of the research, giving examples from the sources. (3 marks) 03 The earlier research described above found a correlation between racial bias and performance on the Stroop test. The researchers came up with a hypothesis to explain the correlation and designed the research reported in this case study to test their hypothesis. Explain the hypothesis being tested. Use any of the sources that you find helpful including Source D (the relevant information is in the second paragraph of D, bottom of first column) (4 marks) Page 9 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets 04 Use the information in the third paragraph of Source D that starts “Given the focus of the proposed resource depletion model”. Very briefly outline what is known about the function of the two brain regions DLPFC and ACC, chosen for investigation in the fMRI. (2 marks) 05 How do the scientists writing the paper, Source D acknowledge their sources of information about these brain regions? (2 marks) The evidence presented in source D is partly in the form of three scatterplots, Figure 2 a & b and Figure 3. These plot ‘mean percentage signal change’ against IAT or Stroop scores. Questions 06 – 08 are about these Figures. 06 What two sets of signals from the fMRI are used to calculate this percentage signal change? Use the results section of the paper. (2 marks) 07 Which of the two brain regions investigated shows the greater correlation between signal change and IAT score in Figure 2? Give the reasons for your choice. (2 marks) 08 In plotting graphs the two variables are called the dependent variable and the independent variable. The dependent variable may be caused by the independent variable. In plotting graphs it is conventional to put the independent variable on the x-axis. In this paper percentage signal change is treated as a dependent in Figure 2 and an independent variable in Figure 3. Explain how this relates to the hypothesis being tested. (4 marks) Questions 09 and 10 are about the Implicit Association Test, IAT. 09 Explain how measures of time taken to complete the task can be converted into a measure of racial bias, using any of the sources you find helpful. (2 marks) 10 Using Source B explain how it is possible to provide an alternative explanation for the IAT data. (3 marks) 11 Do you think the research described in these sources shows that fMRI could be used to detect whether someone has racist views? Explain your answer. (2 marks) 12 Do you think it would desirable to have such a test, if it were 95% reliable? (3 marks) Page 10 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges A2 Science In Society 3.3 Student sheets Questions 13 and 14 are about the quote in Source A where the lead researcher, Jennifer Richeson is quoted as saying that ‘The work …paints a dispiriting portrait of the state of the nation's race relations’ 13 Give two reasons why this claim is not justified by the research evidence. (2 marks) 14 Suggest why Richeson may have made this claim to the journalist (assuming she was not misquoted). (2 marks) 36 marks Section B Some of the marks will awarded for your ability to use an appropriate form and style of writing, to organise relevant information clearly and coherently, and to use specialist vocabulary, where appropriate. 15 This case study includes examples of two different ways of communicating new science findings, popular journalism and the scientific paper. Sources A and C make quite dramatic and probably sometimes exaggerated claims about this research. They go beyond the original scientific paper in some ways to attract interest and to discuss implications. Few members of the public are likely to bother to read the original paper. Are the journalists being irresponsible or fulfilling an important role in informing public debate about science? Are some popular articles more effective than others? Discuss the advantages and disadvantages of the two different ways of communicating new science findings, using examples from sources in this case study. (12 marks) (Unit 4 exam has two 12 mark questions in this section) Page 11 ©The Nuffield Foundation, 2009 Copies may be made for UK in schools and colleges