Lesson 10 - Ways of Studying The Brain

Question 1

What does functional magentic resonance imaging (fMRI) do

Answer 1

• Provides INDIRECT measure of neural activity

• Measures change in energy released by haemoglobin

• Reflects brain activity
-oxygen consumption

Question 2

How do fMRIs work

Answer 2

• Use magnetic fields and radio waves to monitor blood flow in brain

• Gives moving picture of brain

• Activity in areas can be compared during base line task

Question 3

+ Strength of using fMRIs over post-mortem examination

Answer 3

• Capture dynamic brain activity

• Opposed to solely physiology of brain
-compared to post-mortem examination

Question 4

+ Strength of using fMRIs over EEG/ERP

Answer 4

• Has good spatial resolution

• fMRIs have spatial resolution of approximately 1-2mm

• Allows psychologists to differentiate activity in specific regions to greater degree of accuracy
-compared to EEG/ERP

Question 5

• Weakness of using fMRI compared to EEG/ERP

Answer 5

• Has poor temporal resolution

• fMRIs have temporal resolution of 1-4s

• EEG/ERP have 1-10ms

• Psychologists unable to predict onset of brain activity to high degree of accuracy

Question 6

What do electroencephalograms (EEGs) do

Answer 6

• DIRECTLY measure GENERAL neural activity in brain

• EEG patterns produced

Question 7

How do EEGs work

Answer 7

Electrodes placed on scalp

-detect neuronal activity directly below where placed

Question 8

What is an EEG pattern

Answer 8

Electrical signals from different electrodes graphed over period of time produces EEG pattern

Question 9

How do EEG patterns differ in patients

Answer 9

• Epileptic patients show spikes of electrical activity

• Brain injury patients show slowing of electrical activity

Question 10

+ Strength of using EEG compared to fMRI

Answer 10

• Cheaper

• Better temporal resolution

• fMRIs have temporal resolution of 1-4s

• EEG/ERP have 1-10ms

• Psychologists able to predict onset of brain activity to high degree of accuracy

Question 11

• Weakness of using EEG compared to fMRI

Answer 11

• Poor spatial resolution

• Doesn’t allow psychologists to differentiate activity in specific regions to greater degree of accuracy

Question 12

+ Strength of using EEG in clinical diagnosis

Answer 12

• Can record neural activity associated with epilepsy

• Doctors can confirm person is experiencing seizures

Question 13

What do event-related potentials (ERPs) do

Answer 13

• DIRECTLY measure neural activity in response to SPECIFIC stimulus from researcher

Question 14

How do ERPs work

Answer 14

• Electrodes placed on scalp

• ERPs take averages of specific electrical responses to the stimulus

• Extraneous/background neural activity ignored

Question 15

+ Strength of using ERPs (specific)

Answer 15

• Can measure processing of stimulus even in absence of behavioural response

• Possible to covertly measure stimulus processing

Question 16

+ Strength of using ERPs over fMRIs

Answer 16

• Cheaper

• Better temporal resolution

• fMRIs have temporal resolution of 1-4s

• EEG/ERP have 1-10ms

Question 17

• Weakness of using ERPs over fMRIs

Answer 17

• Worse spatial resolution

• Doesn’t allow psychologists to differentiate activity in specific regions to greater degree of accuracy

Question 18

• Weakness of using ERPs (specific)

Answer 18

• Only strong voltage changes across scalp are recordable

• Important electrical activity occurring deeper in brain not recorded

• Generation of ERPs restricted to neocortex

Question 19

What do post-mortem examinations do (aka autopsy)

Answer 19

• If someone is weird then

• When person dies abnormalities in brain are looked for

• Trying to explain weird behaviour

Question 20

+ Strength of post-mortems compared to others

Answer 20

Allow for more detailed look at anatomy and neurochemistry

Question 21

• Weakness of post-mortems(2)

Answer 21

• Lack validity

• People die and disease, time between death and autopsy, drugs can all affect the brain

Question 22

• Weakness of post-mortems

Answer 22

• Small sample size

-Must have special permission to perform autopsy

• Not representative of target population

-Can’t generalise findings