Research Methods

Question 1

What are the different types of brain scan?

Answer 1

MRI and FMRI
PET scans
CT scans

Question 2

What is the difference between a FMRI and MRI?

Answer 2

MRI- black and white grey scale showing the anatomy
FMRI- black and white showing activity of the brain- as it measures blood and oxygen flow

Question 3

How does an MRI/ FMRI work?

Answer 3

A dye is injected into the body
A computer then measures how long hydrogen ions take to return to the body
The grey scale image can be used to identify damage in tissue in the physical structure of the brain.

Question 4

What are the advantages of using an MRI/ FMRI?

Answer 4

• An fMRI also measures functioning as well as structural imaging- helping to identify differences in blood and oxygen flow
• Not biologically invasive and no harm from radiation
• Localisation of function- identify areas responsible for different human functions

Question 5

What are the disadvantages of using MRI/ fMRI?

Answer 5

• Can be potentially harmfully due to magnetic field passed through the body
• Cannot be used on people who have claustrophobia or those with pacemakers
• Expensive: £900- £3000

Question 6

How does a PET scan work?

Answer 6

A radioactive tracer is injected into the body
It emits positrons to show where glucose is being used (active)
Thermal image identifies glucose uptake to show activity
The warmer the image (red/ orange) the higher activity.

Question 7

What are the advantages of a PET scan?

Answer 7

• Clearly shows activity within certain areas of the brain during specific tasks
• Helps to pinpoint what areas of the brain are active
• The functioning/ activity are shown in real time to show changes in activity during task.
• Localisation of function

Question 8

What are the disadvantages of PET scans?

Answer 8

• Cannot be used on individuals who are pregnant or those who have a fear of needles
• expensive - £900- £3000- potentially selective around individuals due to the price
• functioning may be different to actually aggressive functioning
• also cannot identify whether difference in functioning is the cause or effect of aggression.

Question 9

How does a CT scan work?

Answer 9

• Several x-rays are conducted at one time which takes x-rays of “slices of the brain” from different angles
• Produces 2D and 3D images of the brain
• Used to show physical structures of the brain from all angles

Question 10

What are the advantages of using CT scans?

Answer 10

-Tracer not used so not physically invasive
- Detailed image showing ‘subcortical’ areas and components of the brain
- Identify differences

Question 11

What are the disadvantages of CT scans?

Answer 11

• Cannot identify differences in functioning of activity (only structure)
• Harmful radiation can damage cells
• Only identify differences in components in regards to structure/ volume size differences

Question 12

What are correlational studies?

Answer 12

Measure co-variables

Question 13

What are the three trends in correlation?

Answer 13

Positive correlation
Negative correlation
No correlation

Question 14

How is a positive correlation recognised?

Answer 14

As one variable increases, so does the other

Question 15

How is a negative correlation recognised?

Answer 15

As one variables increases, the other decreases

Question 16

How is no correlation recognised?

Answer 16

There is no visible relationship between the co variables

Question 17

Describe the use of correlational studies (3 marks)

Answer 17

Correlations aim to investigate a relationship between two variables. There are two sets of data that have to be taken into account to assess whether there is a link between co variables. A positive correlation is when one variable increases, so does the other. However, a negative correlation is when one variable increases the other decreases. Correlations are measured with a correlation coefficient to show how strong the relationship is between two variables. It ranges in a scale from -1 to +1. A strong positive correlation would be closer to +1 while a strong negative correlation is closer to -1.

Question 18

How is the correlation coefficient calculated?

Answer 18

Using Spearman’s Rank

Question 19

Compare fMRI scans and PET scans in biological psychology (4 marks)

Answer 19

One similarity between fMRI and PET scans is that participants need an injection before the scans can be conducted, a dye is required for an fMRI while a radioactive tracer is used for a PET scan. Another similarity is that both scans show activity in certain areas of the brain by measuring glucose uptake.
However, PET scans takes thermal imaging in order to identify where greater activity is present, while an fMRI uses a greyscale showing measurements of oxygen and blood flow. Finally, a PET scan will only highlight activity when an individual is carrying out a task, a fMRI shows structures and tissue matter in the brain.