The Biological Area Classical study Blakemore and Cooper

The Biological Area Classical study: Blakemore and Cooper (1970) Impact of early visual experience Contemporary study: Maguire et al. (2000) Taxi drivers

Contemporary study: Maguire et al. (2000) ‘Taxi Drivers’ Area: Biological area Theme: Brain plasticity

Maguire et al. (2000) Wanted to investigate brain plasticity in real life • Define brain plasticity: Specifically, wanted to investigate the navigation-related structural changes in the hippocampus of London taxi drivers

What is the hippocampus? Maguire wanted to look at navigation-related structural changes in the hippocampus Research into the role of the hippocampus has shown its importance in memory, specifically spatial memory.

Why London taxi-drivers? • Maguire wanted to investigate the hippocampus – the area responsible for spatial memory. • London taxi drivers undergo extensive training, known as ‘The Knowledge’. • Watch the video to see how complex ‘The Knowledge’ is https: //www. youtube. com/watch? v=u 7 gp 8 KBP 7 ak Explain why London taxi-drivers are an ideal group of participants for Maguire’s study

Aim: To examine whether structural changes could be detected in the brain of people with extensive experience of spatial navigation (taxi drivers) To see if there is a correlation between length of taxi-driving experience and measure of grey matter volume. This will show the extent of brain plasticity

Sample: Group 1: The participants • 16 participants in total • All male • All London taxi drivers (minimum 1. 5 years experience) • All right handed • Aged between 32 and 62 (mean = 44) • Healthy medical, neurological and psychiatric profiles Group 2: The control • 50 participants in total • All male • All do not drive taxi’s • All right handed • Aged between 32 and 62 (Mean age 44) • Healthy medical, neurological and psychiatric profiles Highlight all of the similarities between groups Why is it important to have a comparison group?

Methodology What experimental design is used? Consider the following: • There are two groups who are matched on important variables • Matched Pairs Design requires equal numbers in each group This study is a quasi experiment • Define: • Explain why • Independent variable (IV) is whether the participants were taxi drivers or nontaxi drivers • Dependent variable (DV) is the volume of each participants hippocampus • The study involves correlational analysis as there is no manipulation of variables

Procedure A structural MRI scan was given to each participant. This involves using a computer software programme to produce a 3 D image of the brain.

Procedure The brain scans were analysed using two techniques. • 1 st Technique – Voxel-Based Morphometry. Identifies differences in the density of grey matter in different parts of the brain. Grey matter has dense neural connections and is associated with higher order thinking. • Pixel 2 nd technique counting - A pixel is a single point on a graphic image. In order to calculate hippocampal volume, pixels were counted on photographic ‘slices’ made through the brain using an MRI scan. See image

Control The person counting the pixels was ‘blind’ to whether the brain belonged to a taxi driver or control participant • Why is this a good thing? • What does this mean in terms of the results?

Results: • The taxi drivers had greater grey matter volume in their posterior (back) right hippocampus. • Controls have greater volume in their anterior (front) hippocampus. • These results are significant at p <0. 05 Maguire wanted to examine whether structural changes could be detected in the brain of people with extensive experience of spatial navigation. • What did Maguire find in relation to the structural changes in the brain of taxi drivers in comparison to non-taxi drivers?

Correlational Analysis • A comparison of length of driving experience with the measure of grey matter volume of the taxi drivers the longer the person had been a taxi driver the more grey matter there was • What type of correlation is this? Positive, negative or no correlation? • The results were p<0. 05 • What does this mean?

Conclusions 1. The difference in taxi drivers’ hippocampus may have led them to do a job which requires navigational skills as they are good with that OR 2. The taxi drivers’ hippocampus may have changed as a result of studying for the ‘knowledge’ thus showing plasticity of the brain. The results of the correlational analysis would support the second idea – because the longer they had been a taxi driver, the greater the volume of their right posterior hippocampus.

Watch the following videos to consolidate your understanding of the study • https: //www. youtube. com/watch? v=l. BBge 0 b. X 2 Ng • https: //www. youtube. com/watch? v=KI 6 r 3 Hq. Ck 1 k

Evaluations Research Method 1. Where was the study conducted? • Strengths: (a) What level of control is there in this environment? (b) What type of relationship does this allow for? (c) What can we assume about the IV and the DV? • Weaknesses: (a) As this type of environment is false, what can we assume about any behaviour which is measured within it? 2. MRI scanner • Is this scientific? • Are there likely to be incidences of • Researcher bias • Demand characteristics • Social desirable responses

Evaluations Research Method 3. Correlational analysis • Strength: What does this allow you to see? • Weakness: What does this not allow for? 4. Repeated measures design • What are the strengths of this? Make sure to mention how closely matched the participants are • What are the weaknesses of this? Type of data Quantitative – in terms of density of brain area (a) What does the data gathered tell us? (b) What does it allow us to do? (c) what are the limitations of this type of data?

Evaluations Ethical consideration • List all 6 ethical guidelines • Identify which were upheld and which were broken Validity • Internal validity – the aim of Maguire’s study was to investigate brain plasticity in real life. Does the study really do this? Or are there other factors which may influence? Reliability • Internal reliability – is the study highly controlled and standardised? If yes, the study has high IR. If not, then it does not.

Evaluations Sampling bias • Consider how closely matched the participants are – could there still be any bias? • Gender? • Age? • Occupation? Practical applications • Who in the world would benefit from knowing that your experiences influence your brain? Ethnocentrism • Study was conducted in London – it is assumed the participants would be from London or surrounding areas. Does this mean there is an unfair bias towards those from other cultures? Perhaps it is worth to note that London is very culturally diverse, does this make any difference?

Complete the grid below, outlining and explaining the similarities and differences between Blakemore & Cooper’s study and Maguire’s. Ideas for comparison: Similarities Differences • Sample • Sampling method • Experimental design • Experimental method • Type of data gathered • Way in which data was gathered • Ecological validity • Internal reliability • Mundane realism • Link to debates

Exam questions • In your workbooks, there are 11 exam questions for you to work through. • Be mindful of questions 5 and 6, where it asks what is the strengths/weaknesses of using a correlation in this study – you need to be specific – why is it good in this particular study to use a correlation, not an experiment (think of what a correlation tells you or doesn’t). • Remember, for questions 8 and 9, follow the structure • State that one similarity/difference is X (1 mark) • Explain what X is in study 1 – be specific (1 mark) • Explain what X is in study 2 – be specific (1 mark) • Remember, for questions 10 and 11 follow the structure: • State theme/clearly explain area (1 mark) • Briefly explain what study looked at – specify variables (1 marks) • Clearly explain how both link together – what are they both interested in? (1 mark)