The use of brain scanning techniques to investigate behaviour

Question 1

Examples of non invasive methods?

Answer 1

PET, CAT and fMRI scans

Question 2

How do Computerised Axial Tomography scans work?

Answer 2

> uses x ray beams passed through the head from different angles, creating cross sectional images so showing brain structure but not function
if there is damage, observe behaviour

Question 3

What is involved in the procedure of a CAT scan?

Answer 3

> all jewellery, glasses, metel removed, injection of dye to expose blood vessels
(20-30 mins) must keep still, painless
staff leave room, scanner table moves through scanner and takes pictures while rotating around your head

Question 4

What does Positron Emission Tomography do?

Answer 4

Doughnut shaped scanner put around the head, shows activity of which parts are most/least active from different colours, warm = more activity, uses glucose and water

Question 5

What is involved in the procedure of PET?

Answer 5

> Tracers injected into the bloodstream, brain takes up oxygen in the water/glucose and tracer decays
Tracer takes 10-15mins to decay, releases radioactivity, most active areas leave most radiation

Question 6

What is a tracer in PET?

Answer 6

Radioactive versions of chemicals used up in brain activity - glucose/water, reaches brain after 1 min, helps PET as active brain areas use most glucose leaving radiation

Question 7

What are positrons in PET?

Answer 7

Positively charged particles, they give signals that are picked up by recordings, radioactivity in the form of gamma rays which are produced when positrons collide with electrons

Question 8

Example of how PET works?

Answer 8

If studying blood flow to brain, when someone is talking blood flow will be greater in areas that are most active in order to be able to talk

Question 9

Which scans are ethical and why?

Answer 9

PET, fMRI and CAT because they are non invasive

Question 10

Why could PET scans be slightly invasive?

Answer 10

Injection of glucose tracer, can be distressing

Question 11

Why are PET scans valid?

Answer 11

They measure what they claim to do, validity can be different to check when measuring cognitive functions but PET scans have reconfirmed previous findings

Question 12

What is a weakness of PET scans?

Answer 12

Hard to pinpoint exact areas of the brain so even if PET scans are clear, they are only valid up to a point as it is hard to claim from a scan whih area is performing each function

Question 13

A strength of PET?

Answer 13

movement does not ruin the scan

Question 14

How long does PET take?

Answer 14

2 hours

Question 15

How long do fMRIs take?

Answer 15

2 hours

Question 16

Strengths of CAT scans?

Answer 16

quick and accurate deails of brain structure, non invasive and not painful, may removed need for exploratory surgery

Question 17

Weaknesses of CAT scans?

Answer 17

Doesn’t show function unlike PET and fMRI, involves x rays so should be used sparingly due to radiation

Question 18

What did Maguire et al (1997) find as an example of PET?

Answer 18

The hippocampus was active when the taxi drivers described routes from one location to another, associatied with spatial memory

Question 19

How does fMRI work?

Answer 19

Brain activity associated with blood flow in the brain and this activity is used to gather the info by the scanner to produce a picture

Question 20

What is the process of fMRI?

Answer 20

> Place head in electrmagnet
Magnetic field: nuclei within hydrogen molecules will align themselves with the direction of the magnetic field
Scanner sends the info to the compueter to create the map of activation

Question 21

What happens in the magnetic field of fMRI?

Answer 21

> neural activity increases in the brain, blood flow increases in active areas to meet demand for oxygen
oxygen carried to the neurons in haemoglobimn within red bood cells

Question 22

What happens when haemoglobin carries oxygen in fMRI?

Answer 22

Repels a magnetic field and when deoxygenated it will follow the same direction of the magnetic field and the canner will detec changes to create an image

Question 23

What does the map of activation show in fMRI?

Answer 23

Changing levels of neural activity in different brain areas as tasks are being completed

Question 24

Why is fMRI a more ethical method of investigation?

Answer 24

Takes images from outside the body

Question 25

What are the risks with fMRI?

Answer 25

> someone with a pacemaker would not be able to have one as the magnetic field wouuld cause disruption to the heart
can be claustrophobic

Question 26

Can small movements ruin fMRI?

Answer 26

yes

Question 27

A weakness of fMRI?

Answer 27

The brian is never at rest, it is hard to be totally sure which part of the brain is involved in what

Question 28

Why is fMRI good at looking a changes in brain functioning and structure?

Answer 28

Its sensitivity to changes in blood flow makes identification clear

Question 29

Why are fMRI scans valid?

Answer 29

What is found by the scans is real but it takes place in an artificial setting so ecological validity is ruined which means ppts may not show natural behaviour

Question 30

How are video games linked to aggression?

Answer 30

Montag et al (2011) used fMRI scans and found that gamers showed lower levels of activity in reaction to pictures of negative emotion than the control group did

Question 31

What does little reaction to negative emotions from gamers implicate about their brains?

Answer 31

Gamers who play violent games may be more aggressive as they see aggressive actions as less serious because their brains do not process them in that way