9- studying the brain

Question 1

describe the procedure for post-mortem

Answer 1

when a person dies the brain is examined for abnormalities

Question 2

advantages of post-mortem (1)

Answer 2

+ allows for more detailed examination of anatomical and neurochemical aspects of the brain

Question 3

disadvantages of post-mortem (2)

Answer 3

• studies may lack validity due to small sample size

- length between death and post-mortem and drug treatments can affect the brain

Question 4

describe the procedure of fMRI

Answer 4

• uses magnetic fields and radio waves to monitor blood flow to the brain
• measures change in energy released by haemoglobin reflecting brain activity (oxygen consumption)

Question 5

advantages of fMRI (2)

Answer 5

+ captures dynamic brain activity

+ activity in areas of interest can be compared during a base line task and specific activity

Question 6

disadvantages of fMRI (2)

Answer 6

• interpretation is complex and affected by temporal resolution, biased interpretation and by the base line task used
• expensive leading to reduced sample sizes which affects validity

Question 7

describe the procedure of EEG

Answer 7

• measures GENERAL electrical activity in the brain
• electrodes are placed on the scalp and detect neuronal activity below where they are placed
• electrical signals are graphed over a time period to show an EEG pattern

Question 8

advantages of EEG (2)

Answer 8

+ useful in clinical diagnosis

+ cheaper than fMRI so can be used widely in research

Question 9

disadvantages of EEG (1)

Answer 9

• poor spatial resolution

Question 10

describe the procedure of event-related potential

Answer 10

• electrodes placed on the scalp and detect neuronal activity in response to a SPECIFIC stimulus introduced by the researcher
• Stimulus presented many times and an average is calculated
• ERP waves are generated in the first 100 milliseconds after the stimulus is presented and are called sensory ERPs.
• ERP waves generated after this are called cognitive ERPs

Question 11

advantages of event-related potential (1)

Answer 11

+ can measure processing of a stimulus

Question 12

disadvantages of event-related potential (2)

Answer 12

• only very strong voltage is recordable and activity deep in the brain isn’t recorded
• generation of ERPs are restricted to the neocortex