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The Biological or Physiological The Biological or Physiological ApproachApproach

How many of your behaviours are How many of your behaviours are determined by your biology?determined by your biology?

The Biological or Physiological The Biological or Physiological ApproachApproach

The main assumptions of the biological The main assumptions of the biological approach are that behaviour is significantly approach are that behaviour is significantly determineddetermined by any or some of the following: by any or some of the following:

1. Our genes and personality1. Our genes and personality 2. Our brain structure and function2. Our brain structure and function 3. Our hormones – testosterone, oestrogen, 3. Our hormones – testosterone, oestrogen,

adrenaline etc.adrenaline etc. 4. Disease, injury and substance abuse4. Disease, injury and substance abuse

We all have the same biological We all have the same biological make up and are even almost make up and are even almost

identical in our genetic identical in our genetic structures to most animals and structures to most animals and

in particular primates.in particular primates.

So many studies in the past have So many studies in the past have therefore looked at animals as therefore looked at animals as comparisons !comparisons !

Questions psychologists have Questions psychologists have asked about brain structure?asked about brain structure?

To what extent are we born with our To what extent are we born with our brain structure and to what extent brain structure and to what extent can we extend and develop our brain can we extend and develop our brain structure and function through structure and function through learning?learning?

The nature v nurture debate!The nature v nurture debate!

Birds and migrationBirds and migration

Studies into bird migration have Studies into bird migration have shown changes in their brain shown changes in their brain structure immediately after a long structure immediately after a long period of migratory flight.period of migratory flight.

Measurement problemsMeasurement problems

Before brain scanning we could only carry Before brain scanning we could only carry out investigations on humans on dead out investigations on humans on dead people and so had no way of measuring people and so had no way of measuring changes in brain structure through changes in brain structure through peoples lives.peoples lives.

Most people only learn small amounts of Most people only learn small amounts of new information at one time so most of new information at one time so most of our learning we do would be impossible to our learning we do would be impossible to measure anyway as if there were brain measure anyway as if there were brain changes they would be too small to changes they would be too small to identify even on a scan!identify even on a scan!

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Maguire et al (2000) Maguire et al (2000) your amazing brain! your amazing brain!

A London Taxi A sea horse

What do these have to do with your brain!

Greek namehippocampus

Brain structure and functionBrain structure and function

For this study you need to be able to For this study you need to be able to describe or draw where the describe or draw where the hippocampus is in the brain and also hippocampus is in the brain and also understand the differences between understand the differences between white matter and grey matter in the white matter and grey matter in the brain!brain!

The main head or cell body of The main head or cell body of the brain cell is the grey matter the brain cell is the grey matter whilst the stalk or connections whilst the stalk or connections

are the white matter!are the white matter!

YouTube - Hippocampal Neuron in 3D rotation

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The hippocampus is the part of the brain that The hippocampus is the part of the brain that stores spatial memory and navigation stores spatial memory and navigation

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Why HIPPOCAMPI?

Each hemisphere of the brain has a

hippocampus

hippocampi means TWO

YouTube – hippocampus

YouTube - Hippocampus; 3-D Brain animation

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Research Question: Can changes in the brain be detected in those Research Question: Can changes in the brain be detected in those with extensive navigation experience ? with extensive navigation experience ?

The hypothesis:The hypothesis:

That the hippocampi in London Taxi drivers will be structurally That the hippocampi in London Taxi drivers will be structurally different to the hippocampi in non-taxi driversdifferent to the hippocampi in non-taxi drivers

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London Taxi Drivers ‘On the knowledge’London Taxi Drivers ‘On the knowledge’

It takes two years to train to become a London Taxi driverIt takes two years to train to become a London Taxi driver

Must memorize thousands of routes Must memorize thousands of routes

Tested by police before a license issuedTested by police before a license issued

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Method: Natural or Quasi Method: Natural or Quasi experimentexperiment

2 groups of volunteer participants 2 groups of volunteer participants IV IV London Taxi driver brain London Taxi driver brain Non taxi driver brainNon taxi driver brain

DVDV structure & volume of structure & volume of hippocampihippocampi

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ParticipantsParticipants16 right handed, male, taxi drivers16 right handed, male, taxi driversaverage age 44, all licensed more average age 44, all licensed more

than 18 months, average time as than 18 months, average time as taxi driver 14.3 yearstaxi driver 14.3 years

16 right handed, male, age matched, 16 right handed, male, age matched, non taxi drivers non taxi drivers

Why all right handed?Why all right handed?

YouTube - The Right Brain vs Left Brain test - Optical Illusion

YouTube - what does THIS dancer say about YOU?

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The procedureThe procedure::MRI scans of brains of 50 healthy, right MRI scans of brains of 50 healthy, right

handed, male, non taxi drivers aged 33 handed, male, non taxi drivers aged 33 - 61 were analysed to establish a - 61 were analysed to establish a comparison data base of ‘average comparison data base of ‘average hippocampi’hippocampi’

analysis by Voxel Based Morphometry analysis by Voxel Based Morphometry (VBM) (VBM) YouTube - my brain (YouTube - my brain (mrimri scan) scan)

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The procedure:The procedure:MRI scans of brains of 16 male taxi MRI scans of brains of 16 male taxi

drivers and of 16 matched controls were drivers and of 16 matched controls were analysed by VBM and compared to the analysed by VBM and compared to the data base of images data base of images

Further CONTROL: the expert conducting Further CONTROL: the expert conducting the analysis did not know whether MRI the analysis did not know whether MRI scan was taxi driver brain or notscan was taxi driver brain or not

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Findings (1):Findings (1):

increased volume of grey matter in increased volume of grey matter in both the right & left hippocampi in both the right & left hippocampi in taxi driver brainstaxi driver brains

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Maguire et al (2000)Maguire et al (2000)

LH

left hemisphere

RH

Right hemisphere

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Findings (2): A Correlation was found Findings (2): A Correlation was found betweenbetween

The length of time as taxi driver and The length of time as taxi driver and the volume increase of the right the volume increase of the right posterior hippocampus.posterior hippocampus.

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Maguire et al (2000)Maguire et al (2000)

Findings (2): Correlational analysisFindings (2): Correlational analysis

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Maguire et al (2000)Maguire et al (2000)

Findings (3)Findings (3)taxi drivers had greater volume in taxi drivers had greater volume in

the posterior hippocampus but non the posterior hippocampus but non taxi drivers had greater volume in taxi drivers had greater volume in the anterior hippocampus the anterior hippocampus

indicating REDISTRIBUTION of grey indicating REDISTRIBUTION of grey matter in hippocampusmatter in hippocampus

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Maguire et al (2000)Maguire et al (2000)

Conclusion:Conclusion:That the structure of the brain That the structure of the brain

changes in response to changes in response to environmental demand environmental demand

Conclusion:Conclusion:That the mental map of the city of That the mental map of the city of

London is stored in the posterior London is stored in the posterior hippocampihippocampi

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Maguire et al (2000)Maguire et al (2000)

Is this useful?Is this useful?The evidence that normal activity The evidence that normal activity

can induce changes in the structure can induce changes in the structure of the brain, and in the volume of of the brain, and in the volume of grey matter, has many implications grey matter, has many implications for rehabilitation after brain injuryfor rehabilitation after brain injury

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Maguire et al (2000)Maguire et al (2000) Ecological Validity? Ecological Validity?

Is the way the experiment measures Is the way the experiment measures the DV (brain structure)the DV (brain structure)

and the experimental setting and the experimental setting and the sample of participants and the sample of participants

realistic in a real life setting?realistic in a real life setting?Discuss: why or why not?Discuss: why or why not?

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Maguire et al (2000)Maguire et al (2000) Types of dataTypes of data

discuss: strengths & limitations discuss: strengths & limitations

Quantitative = matters of fact Quantitative = matters of fact objective, scientific & replicableobjective, scientific & replicable

useful for analysis & comparisonuseful for analysis & comparisonor:or:Qualitative = matters of opinionQualitative = matters of opinionsubjective, rich in detail, can be hard subjective, rich in detail, can be hard

to analyse, may be misinterpretedto analyse, may be misinterpreted

Maguire et al (2000)Maguire et al (2000) The experimental methodologyThe experimental methodology

Was the method appropriate for the Was the method appropriate for the aim?aim?

Are the experimental conditions Are the experimental conditions realistic (mundane realism = real realistic (mundane realism = real world realism – ecological validity) world realism – ecological validity)

How was the DV operationalised and How was the DV operationalised and was this a valid measure of the was this a valid measure of the behaviour being studied? behaviour being studied?

Maguire et al (2000)Maguire et al (2000) The experimental procedureThe experimental procedure

How were the participants allocated How were the participants allocated to the conditions and were controls to the conditions and were controls used to remove ‘extra variables’ ? used to remove ‘extra variables’ ?

Were there any cues that might have Were there any cues that might have generated demand characteristics ? generated demand characteristics ?

RELIABILITY: Could the study be RELIABILITY: Could the study be replicated to find the same results? replicated to find the same results? Why or why not?Why or why not?

Maguire et al (2000) Maguire et al (2000) The sample The sample

Who were the participantsWho were the participantsWas the sample biased in any way?Was the sample biased in any way?Was the sample large enough to mask Was the sample large enough to mask

the effect of individual differences?the effect of individual differences?To which population can we safely To which population can we safely

generalise the findings?generalise the findings?

What does the McGuire study tell us What does the McGuire study tell us about the biological processes of about the biological processes of behaviour?behaviour?

How are these findings useful in How are these findings useful in everyday life?everyday life?

Suggest two improvements to the Suggest two improvements to the study and say how these would affect study and say how these would affect the data?the data?

How is this study similar and different How is this study similar and different to the other two biological studies.to the other two biological studies.