Discuss the use of brain-imaging technologies in investigating the relationships between biological factors and behaviour

Question 1

Where are brain-imaging techniques used? What are they used for? Give an example (3)

Answer 1

• in neuroscience
• to investigate the relationship between behaviour and brain structures
• e.g. after brain damage or to find out which areas of the brain are involved in which cognitive activities (cog. neuroscience)

Question 2

In what way is brain-imaging technology promising? What is the case so far? (2)

Answer 2

• to investigate the possible relationship between biological factors and behavior
• so far scanning can merely register structures and activity in the brain = not possible to determine cause-effect relationships at this point

Question 3

What does MRI stand for?

Answer 3

• magnetic resonance imaging

Question 4

What can MRI scans do? How do they work? (1) (5)

Answer 4

• give detailed pictures of internal structures in the body
• body consists largely or water molecules
• MRI scanner produces electromagnetic field
• radio waves knock H2O protons out of position
• they get back in position sending out signals
• picked up by radio wave receivers

Question 5

Strengths and limitations of MRI (2)(3)

Answer 5

Strengths:

• particularly useful to show how the blood flows in the brain = can be used to identify problems with blood circulation = can be used for early detection of Alzheimers’ disease
• safe to use since no radioactive material used

Limitations:

• very expensive
• movement may affect pictures
• cannot say anything about cause-effect relationships

Question 6

MRI study: what is it called? (1)

Answer 6

• Ashtari et al. (2009)

Question 7

MRI study: Ashtari et al. (2009) (7)

Answer 7

Aim: used to investigate whether substance abuse (marijuana) can damage the developing brain in adolescents and young adults

Method:

• researchers scanned brains of 14 young men with history of heavy marijuana abuse over a long period
• control group consisted of 14 young men who had not used marijuana

Findings:

• results of scan indicated that there were brain abnormalities in frontal parietal and temporal regions of marijuana users
• development of white matter (myelin) was affected = could explain slow information processing in brain

Conclusion:
- researchers concluded that early marijuana use can affect brain development negatively

Evaluation:
- study gave correlational data so more research is needed

Question 8

What does fMRI stand for? (1)

Answer 8

• functional magnetic resonance imaging

Question 9

What does the fMRI scanner measure? What is the thing it is measuring associated with? How can scientists use it? What has happened to its use in science in the last 10 years? (4)

Answer 9

• changes in blood flow in the active brain
• use of oxygen and linked to neural activity during information processing
• when participants are asked to perform a task, the scientists can observe the part of the brain that corresponds to that function
• use increased enormously

Question 10

Strengths and limitations of fMRI (2)(2)

Answer 10

Strengths:

• it does not use radioactive substances
• it can record activity in all regions of the brain

Limitations:

• focus mostly on localised functioning in the brain and does not take into account the distributed nature of processing in neural networks
• results are correlational = not possible to establish cause-effect relationships

Question 11

fMRI study: what is it called? (1)

Answer 11

• Harris and Fiske (2006)

Question 12

fMRI study: Harris and Fiske (2006) (8)

Answer 12

• used fMRI scans to study students’ brain processes as a response to being presented with pictures of extreme outgroups

Aim: to find the biological correlates of stereotypes and prejudice

Method:

• researchers scanned students while they were watching either pictures of different humans or objects
• predicted that medial prefrontal cortex would be active when participants looked at humans but not when they looked at objects

Findings:

• hypothesis correct except when participants looked at pictures of people from extreme outgroups such as the homeless and addicts
• brain regions related to ‘disgust’ were activated + no activity in prefrontal cortex

Conclusion:

• this indicated a dehumanisation of the outgroups
• apparently extreme outgroups viewed as ‘disgusting objects’ not ‘humans’

Question 13

General issues in brain imaging to consider in a discussion (2)

Answer 13

• mainly about mapping brain structures and activity in the brain
• it may be possible to identify brain structures that are active during a test but since most structures are linked to other structures in networks, it is not possible at this point to say defo where things happen in the brain

Question 14

Discuss the use of brain-imaging technologies in investigating the relationships between biological factors and behaviour

Answer 14

• Intro (5)
• MRI intro (4)
• MRI S & W (5)
• MRI study (7)
• fMRI intro (5)
• fMRI S & W (4)
• fMRI study (8)
• General issues (2)