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Physiological Psychology

Maguire(2000)

Lesson outcomes

• Brain scanning technology• Purpose and function of the hippocampus• What is The Knowledge?

Physiological approach in psychology• Physiological psychology focuses on the relationship between our

biological makeup and our behaviour and experiences. • How much does our biology affect us?• Some physiological psychologists take a reductionist argument to answer

the question. That is, they argue that behaviour and experiences can be explained in terms of brain structure and chemicals.

• However, other psychologists take the view that we cannot explain complex human behaviour and experience just in terms of brain structure and chemicals. There are other psychological variables which need to be considered, for example, such as how we act alone compared to how we behave in groups.

• The study you have just learnt by D&K investigates what happens when we sleep.

• The study we are going to cover today by Maguire (2000) investigates the relationship between a structure of the brain called the hippocampus and memory. Both of these studies look at physiological processes.

http://www.youtube.com/watch?v=Li5nMsXg1Lk

Physiological approach

• The most scientific approach in psychology• Mostly uses laboratory experiments• Interested in the brain and nervous system• Uses high tech equipment• May use laboratory observations and

correlations

Maguire (2000)

• Maguire et al. were attempting to demonstrate the plasticity of the brain. Plasticity (or neuro-plasticity) refers to changes that occur in the organization of the brain as a result of experience.

• The researchers studied the hippocampus of London taxi drivers because they were interested to see if the hippocampus would change because of the taxi drivers high dependence on navigational skills

The 10% mythIt has been suggested that we only use 10% of our brains

This is a belief held commonly amongst the general public, but few scientists

If 90% of our brain is not used then it shouldn’t matter too much if we get brain damage in that 90%

We know what a number of different parts of the brain are used for (Sperry) and there are few areas that appear inactive

The idea that we only use 10% suggests that if we could somehow harness the other 90% we could almost make ourselves superhuman!

Brain scanning: a new technology

MRI Scan: magnetic field

CAT Scan: 180 degree x-rays

fMRI Scan: measures changes in blood oxygen

PET Scan: detects activity

The hippocampus

Give me six facts about the hippocampus on your picture using the Maguire handout and your textooks to help you

The knowledge

Q1. what is the knowledge?

Q2. how are drivers assessed?Q3. how long does the process take?

http://www.psychexchange.co.uk/videos/view/20331/

The Aim

• The aim of the study was to investigate whether changes could be detected in the brains of London taxi drivers and to further investigate the functions of the hippocampus in spatial memory.

Participants • 16 right-handed male licensed London taxi drivers compared with

the scans of 50 healthy right-handed males who did not drive taxis

• Mean age of taxi drivers =44 and range = 32–62 years.

• Licensed London taxi drivers for more than one and a half years (mean time as taxi driver was 14.3 years

• The scans of the 50 control participants were selected from the structural MRI scan database at the same unit where the taxi drivers were scanned. Participants below 32 and above 62 years of age were excluded as were females, left-handed males, and those with any health problems.

Research method

• The study is an example of a quasi or natural experiment because the researchers are comparing the data of taxi drivers and non-taxi drivers. The researchers have no control of this variable as it is naturally occurring.

• The researchers also make use of correlation analysis as they are investigating a relationship between the brain scans and length of time the taxi drivers have been licensed.

Procedure • Data collected using MRI.

• Software converts information into 3D image of brain and analysis can calculate amount of grey matter in hippocampus.

• Data measured using two different techniques – voxel-based morphemetry (VBM) and pixel counting.

• Voxel-based morphology (VBM) used to measure density (amount) of grey matter in brain. VBM provides 3D measurement of volume of an area.

• Pixel counting was carried out on some participants.

• Pixel counting consists of counting pixels in images provided by the MRI scans. A pixel is simply a 2D measurement of an area. Areas were calculated by taking images of slices of the whole length of the hippocampus. Scan=24 slices of hippocampus area (6=posterior, 12=body & 6=anterior)

• The pixel counting was carried out by a researcher who was experienced in this technique and importantly was not aware of the previous VBM results and whether the slices being counted were scans of taxi drivers or controls.

Results• The first main findings of the research were that the

posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and that the anterior hippocampal region was larger in control subjects than in taxi drivers.

• The second main finding was that hippocampal volume correlated with the amount of time spent as a taxi driver (positively in the right posterior and negatively in the right anterior hippocampus).

Include 6 other findings from your handout

Cartoon strip

• Using your notes and textbooks create a comic strip of the procedure and results of the Maguire study to help you revise for this study.

• Keep writing to a minimum and use as much colour as possible!

Conclusions/explanation• Maguire et al. argue that this study demonstrates the plasticity of

the hippocampus in response to environmental demands. (i.e. Affects of ‘The Knowledge’)

• The posterior hippocampus stores a spatial memory of the environment and so in the London taxi drivers the volume (amount) of the posterior hippocampus expanded because of their high use of navigational skills.

• The anterior and posterior hippocampus have different roles. - Posterior involved when previously learned spatial information is

used- Anterior more involved during the encoding of new environmental- layouts.

1. The Maguire et al. study on taxi drivers used MRI scans (Magnetic Resonance Imaging). (a) Explain what an MRI scan measured in this study. [2] (b) Outline one piece of evidence that suggests the brains of taxi drivers are different from the brains of non-taxi drivers. [2] 2. (a) Describe the sample used in the study of taxi drivers’ brains by Maguire et al. [2] (b) Suggest one application of the findings from the study of taxi drivers’ brains by Maguire et al. [2] 3 (a) Explain why Maguire et al. decided to study London taxi drivers in their study. [2] (b) Identify two criteria the researchers used to select the taxi drivers in this study. [2] 4. Identify one control that was used in the Maguire et al. study of taxi drivers’ brains and explain why this control was important. [4] 5 (a) In the Maguire et al. study of taxi drivers brains describe one method used to analyse the MRI scans. [2] (b) Describe one result obtained from this method. [2]

Lesson 3

Introduction to nature v nurture

In your dictionaries:

Nature = a biological explanation for behaviour

Nurture = an environmental, situational, learning explanation for behaviour

Introduction to the Nature v. Nurture Debate

• What would the nature argument be to explain John’s behaviour?

• What was the nurture argument to explain John’s behaviour - what evidence does he find for this?

• http://www.youtube.com/watch?v=5ivNjCdKm04&feature=related

Reductionism• Some physiological psychologists take a reductionist

approach to explaining behaviour. That is, they argue that behaviour and experiences can be explained in terms of brain structure and chemicals.

• For example, aggression in males can be explained by higher levels of testosterone in the body compared to females.

Reductionism is the idea that complex things can always be reduced to (or explained by) simpler things.

Reductionism is the argument that we can explain behaviour and experiences by reference to only one factor, such as physiology or learning.

Evaluation of Maguire’s study into spatial memory

• Research method?• Control• Sample bias and size – generalisability?• Research technique used – MRI scans (S&W)• Qualitative and quantitative data (S&W)• Are there any useful applications from the

study?• Reductionism• Nature/nurture

Think-pair share

• Number your 8 evaluation issues 1,2,1,2,1,2,1,2• Next number yourselves 1 and 2 with the

person sitting immediately next to you on your table.

• You have 5 minutes to explain to your partner, whilst they write down definitions, what the issue is corresponding to your number.

• E.g. If you are number 1 you must explain all of the issues numbered 1.

Washing-line evaluation

• Write each key evaluation issue in your grid onto a different piece of coloured A4 paper leaving space to write around the issue.

• Each group will be given a piece of string, some blue tac and paper clips to hang up your evaluation issues on completion.

• Using the study by Maguire you must explain on the coloured paper how each study can be related.

• Walk around the room examining each washing line and complete your own evaluation grid using the best explanations in the room.

Examples of Section B Q’s1. Describe how behaviour was measured in the

study by Maguire. [6]2. Suggest two changes to the study by Maguire

and outline how these changes might affect the results. [8]

There are a significant number of marks available for these questions, so it is important that you approach this question in the right frame of

mind.

Imagine you’re the examiner…….

In pairs devise your own mark scheme for these questions.

• What features would you expect in a students answer to give them the full 6 or 8 marks for each question?• Be ready to feedback your mark scheme to the rest of the group.