Techniques Used to Study the Brain (DP IB Psychology)

The key finding from the post-mortem analysis in the study of HM is that it confirmed memory is localised to the temporal lobe, specifically the hippocampus.

A strength of using both qualitative and quantitative methods to study the case of HM (Corker, 1997) is that it generates both reliable and rich data in support of the hippocampus being implicated in memory formation.

Broca's area is located in the left frontal lobe, and its function is for speech production.

True.

In Broca's case study of Tan (1861), he could understand speech but could not produce coherent speech.

Broca's aphasia is the inability to produce coherent speech due to damage in Broca's area (left frontal lobe).

True.

A limitation of Broca's (1861) case study of Tan is that there may have been other explanations for Tan’s speech impairment which were not explored at the time.

A longitudinal study is a research method that involves observing and collecting data from the same group of individuals over an extended period.

Both the case studies of HM (Corker, 1997) and Tan (Broca, 1861) are longitudinal studies.

MRI stands for magnetic resonance imaging in brain scanning.

A magnetic resonance imaging (MRI) brain scan works by using a large magnet and pulses of radio waves to scan the brain, producing images of brain structures.

Magnetic resonance imaging (MRI) brain scans are used to determine a correlation between spatial navigation and hippocampal grey matter in the brains of London taxi drivers (Maguire, 2000).

False.

Magnetic resonance imaging (MRI) brain scanning techniques only measure brain structure, not function.

Magnetic resonance imaging (MRI) scans produce a picture of the inside of the brain or body by measuring hydrogen nuclei in the area that is being scanned.

Magnetic resonance imaging (MRI) brain scans might not be suitable for claustrophobic patients because they are prone to disturbances caused by noise, temperature, and human error.

The primary difference between magnetic resonance imaging (MRI) and positron emission tomography (PET) scans is that MRI scans are less invasive than PET scans as it does not require the use of radiation.

It is a strength that magnetic resonance imaging (MRI) scans pinpoint specific brain structures to discover areas that may be damaged or have increased grey matter, to identify the link between brain and behaviour

False.

Maguire (2000) investigated spatial navigation in London black cab taxi drivers using MRI brain scanning techniques.

The participants of the Maguire (2000) taxi driver study are :

• 16 healthy males, aged 32-62 years

• London black cab taxi drivers who had passed ‘The Knowledge’, a test of spatial navigation

Maguire (2000) aimed to investigate the use of MRI brain-imaging technology to investigate spatial navigation in London black cab taxi drivers.

The key findings of the Maguire (2000) taxi driver study:

• The posterior hippocampi of the taxi drivers showed a greater volume of grey matter than the control group

• There is a positive correlation between volume of posterior hippocampal grey matter and length of time spent as a taxi driver

MRI brain scans are used in the Maguire (2000) study as participants brains are scanned to measured the volume of grey matter in the hippocampus. This was compared to the scans of a control group.

True.

A strength of the Maguire (2000) study is the use of MRI scans as a highly controlled clinical method of obtaining objective data, which can be easily compared and analysed.

It is a limitation that the findings of the Maguire (2000) taxi driver study are correlational because correlations cannot show cause-and-effect. So it is impossible to know whether the taxi drivers already had naturally high levels of hippocampal grey matter.

The aim of the Luby et al. (2013) study is to investigate whether poverty experienced in childhood is shown in delayed brain development using MRI brain scanning.

The participants of the Luby et al. (2013) study are:

• 145 children from the USA

• already enrolled on a 10-year longitudinal study of Preschool Depression

• categorised as living in poverty

• The function of the hippocampus in the brain is memory formation

• The function of the amygdala in the brain is associated with emotion

False.

It is a limitation of the Luby et al. (2013) study that the MRI scans may show differences in children's brains which were not the result of poverty but of other, unknown factors.

Luby et al. (2013) concluded that poverty appears to have a negative effect on brain development in childhood, but this can be reduced by the quality of caregiving the child experiences.

Positron Emission Tomography (PET) technique to study the brain uses a radioactive tracer to measure glucose metabolism of specific regions in the brain.

(c)

Functional Magnetic Resonance Imaging (fMRI) measures oxygenated blood flow in the brain.

A strength of an fMRI brain scanning technique is that it enables researchers to measure oxygenated blood in specific brain regions which can inform them of brain activity linked to cognitive processes such as emotion.

True.

An fMRI brain scan is slow, having a 5-second delay between brain activity and measurement so it may miss some important information.

True.

PET scans are not affected by the participant moving slightly whilst being scanned.

One limitation of using a PET brain scan is:

a) The radioactive tracer involves some risk to the patient

In an fMRI, oxygenated blood has a different resonance than deoxygenated blood: more active areas of the brain receive more oxygenated blood.

Each voxel in an fMRI brain scan represents thousands of neurons and contributes to the 3D image of brain activity.

False.

Fisher et al. (2005) investigated the brain systems involved in early-stage romantic love using fMRI scans.

The participants of the Fisher et al. (2005) study are:

• 10 females and 7 males from New York State University

• aged from 18-26 years old

• all reporting being ‘in love’ for a range of 1-17 months

The procedure of the Fisher et al. (2005) study is:

1. participants are placed in an fMRI scanner

2. shown a photograph of their loved one

3. complete a distraction task

4. shown a ‘neutral’ photograph of an acquaintance

The conclusion of the Fisher et al. (2005) study is that people in the early stages of romantic love access brain areas associated with motivation and reward, suggesting people become ‘addicted to love’.

True.

A strength of the Fisher et al. (2005) study is the use of a standardised procedure, making it replicable.

It is a limitation in the Fisher et al. (2005) study that the study has a sample size of 17 because the results are not very meaningful and may not be robust in terms of statistical analysis.

False.

Using PET scans, Raine et al. (1997) aimed to investigate whether there are any differences in the brains of impulsive murderers compared to non-murderers.

The participants of the Raine et al. (1997) study are:

• 41 murderers who had been tried in California for murder or manslaughter

• control group of non-murderers.

The procedure of the Raine et al. (1997) study:

• each participant was injected with a radioactive tracer

• participants were placed in a PET scanner

• participants were asked to complete a series of simple cognitive tasks

The key finding of Raine et al. (1997)'s study is the impulsive murderer group showed less activity in the prefrontal cortex (PFC) and asymmetrical activity in the amygdala, suggesting brain dysfunction may link to violent outbursts.

True.

A strength of the Raine et al. (1997) study is the use of a matched pairs design, controlling individual differences to some extent.

It is a limitation of the Raine et al. (1997) study that the results may lead to a deterministic bias against impulsive murderers, as it suggests they have no free will and blames their murderous acts on their biological functions.