Lesson 9: Studying the brain

Question 1

What are the 4 ways of studying the brain
(Hint: PEEF)

Answer 1

1) Post-mortem examinations
2) Functional magnetic resonance imaging (fMRI)
3) Electroencephalogram (EEG)
4) Event-Related potentials (ERP)

Question 2

What is a post-mortem examination?

Answer 2

when researchers study the BRAIN of a person who displayed a particular behaviour while they were alive

Question 3

Why are post-mortem examinations important?

Answer 3

it has allowed links between BRAIN ABNORMALITIES and psychiatric disorders to be established

e.g reduced level of GLIAL CELLS in the FRONTAL LOBE of patients with depression

Question 4

State a POSITIVE EVALUATION of post-mortem examinations
(hint: detailed examination)

Answer 4

Post-mortem studies have allowed for a more DETAILED examination of ANATOMICAL and NEUROCHEMICAL aspects of the brain that would NOT be possible with other methods of studying the brain

-> enabled researchers to examine deeper regions e.g hypothalamus + hippocampus

Question 5

State a NEGATIVE evaluation of post-mortem examinations
(hint: validity+ circumstance of death)

Answer 5

Post-mortems may lack VALIDITY as people die in a variety of CIRCUMSTANCES and at varying stages of DISEASE.

Similarly, the length of time between DEATH + POST-MORTEM, and drug trearments can all affect the brain

Question 6

State a NEGATIVE evaluation of post-mortem examinations
(Hint: small sample sizes)

Answer 6

• Post-Mortem studies have very SMALLsample sizes (as special permission needs
  to be granted).

This means the sample cannot be said to be representative of the TARGET population and so it is PROBLEMATIC to generalise the findings to the wider population

Question 7

What is fMRI

Answer 7

It’s a NEUROIMAGING technique that provides an INDIRECT measure of NEURAL activity

Question 8

How does fMRI work?

Answer 8

uses MAGNETIC fields and RADIO waves to monitor BLOOD flow in the brain

Question 9

What does fMRI measure?

Answer 9

measures the change in the ENERGY released by HAEMOGLOBIN + it does this by REFLECTING activity of the BRAIN (oxygen consumption) to give a moving picture of the brain

Question 10

State a POSITIVE evaluation of fMRI
(hint: brain activity)

Answer 10

+ fMRIs captures dynamic brain ACTIVITY as opposed to a post-mortem examination which purely show the PHYSIOLOGY of the brain.

Question 11

State a POSITIVE evaluation of fMRI
(hint: spatial resolution)

Answer 11

+ fMRIs have good spatial resolution (refers to the smallest feature that a measurement can detect).

Question 12

State a NEGATIVE evaluation of fMRI
(hint: temporal resolution)

Answer 12

• Interpretation of fMRI is complex and is AFFECTED by poor TEMPORAL resolution (resolution of a measurement with respect to time), BIASED interpretation, and by the base line task used

Question 13

State a NEGATIVE evaluation of fMRI
(Hint: expense + sample size)

Answer 13

• fMRI research is EXPENSIVE leading to REDUCED sample sizes which negatively impact the VALIDITY of the research

Question 14

What does an electroencephalogram (EEG) do?

Answer 14

DIRECTLY measures GENERAL NEURAL activity in the brain, usually linked to states such as sleep and arousal.

Question 15

How doe EEGs work?

Answer 15

Electrodes are placed on the SCALP and detect NEURONAL activity directly below where they are placed

(differing numbers of electrodes can be used depending on focus of the research.)

Question 16

What are EEG patterns?

Answer 16

When electrical signals from the different electrodes are GRAPHED over a period of time

Question 17

What do EEG patterns of patients with epilepsy show

Answer 17

SPIKES of electrical activity

Question 18

What do EEG patterns of those with brain injury show?

Answer 18

a SLOWING of electrical activity.

Question 19

State a POSITIVE evaluation of EEG
(Hint: clinical diagnosis)

Answer 19

EEG is USEFUL in clinical diagnosis-> can be used to record NEURAL ACTIVITY associated with epilepsy so that doctors can confirm the person is EXPERIENCING seizures

Question 20

State a POSITIVE evaluation of EEG
(Hint: cost)

Answer 20

+ EEGs are CHEAPER than an fMRI so can be used more widely in research.

Question 21

State a NEGATIVE evaluation of EEG
(Hint: spatial resolution)

Answer 21

EEGs have a POOR spatial resolution (refers to the smallest feature that a measurement can detect)

Question 22

What are event-related potentials? (ERP)

Answer 22

patterns of NEURAL brain activity that are recorded through EEG in response to a SPECIFIC event or stimuli

Question 23

How do ERPs work?

Answer 23

Electrodes are placed on the scalp and DIRECTLY measure neural activity (below where they are placed) in response to a SPECIFIC stimulus introduced by the researcher.

Question 24

How are event-related potentials measured if it is difficult to distinguish all the other electrical activity being generated within the brain?

Answer 24

1) To establish a SPECIFIC response to a target stimulus it requires many TRIALS of the same experimental STIMULUS

2) RESPONSES are then AVERAGED together and any INCONSISTENT neural activity is NOT related to that specific stimuli

Question 25

State a POSITIVE evaluation of ERPs
(hint: processing of a stimulus)

Answer 25

+ ERPs can measure the processing of a stimulus even in the absence of a behavioural response. Therefore it is possible to measure ‘covertly’ the processing of a stimulus.

Question 26

State a POSITIVE evaluation of ERPs
(hint: cheaper)

Answer 26

+ ERPs are cheaper than an fMRI so can be used more widely in research.

Question 27

State a POSITIVE evaluation of ERPs
(hint: temporal resolution)

Answer 27

+ ERPs have good temporal resolution (unlike fMRIs).

Question 28

State a NEGATIVE evaluation of ERPs
(hint: spatial resolution)

Answer 28

• ERPs have poor spatial resolution (unlike fMRIs).