Ways of studying the brain

Question 1

Ways of studying the brain

Answer 1

-fMRI (functional magnetic resonance imaging)
-EEG (electroencephalogram)
-ERP (Event-related-potentials)
-Post mortem examinations

Question 2

fMRI

Answer 2

-fMRIs measure brain activity by measuring changes in blood oxygenation and flow that occur when a brain area is active
-Activebrain areas consume more oxygen, therefore more blood will flow to them
-Additionally, oxygenated blood has a different resonance to deoxygenated blood
-This produces a 3D image showing which areas of the brain are involved in specific mental processes

Question 3

Evaluations of fMRI

Answer 3

+fMRIs are non-invasive and safe (no radiation), which increases the ethical validity of this brain-studying method
+fMRIs have a high spatial resolution, meaning that researchers can identify specific patterns of activation over time
-However, fMRIs have a low temporal resolution (delay of about 5 seconds between activation and image) meaning that it is difficult to establish cause-and-effect relationships
-fMRIs are expensive to use, limiting it to only certain socioeconomic groups

Question 4

EEG (electroencephalogram)

Answer 4

-EEG uses electrodes placed onto the scalp to measure the electrical activity of neurones in the brain
-it measures general brain wave patterns

Question 5

EEG evaluations

Answer 5

+EEG is non-invasive and relatively inexpensive
+EEG has a high temporal resolution (delay of a few milliseconds between activity and image), making it easier to establish cause and affect
-EEG can only detect surface activity in accessible brain regions- this is a limitation as it does not provide insight into deeper brain regions
-EEG has a low spatial resolution, meaning it is difficult to pinpoint the source of activity in the brain

Question 6

ERPs (event related potentials)

Answer 6

-ERPs use the same apparatus and technique as EEGs (placing electrodes on the scalp to measure the electrical activity of neurones)
-ERPs measure changes in brain activity in response to a stimulus

Question 7

ERP evaluations

Answer 7

+ERPs have excellent temporal resolution- showing brain response to specific events
+ERPs can measure covert cognitive processes such as memory and perception
-ERPs have low spatial resolution- cannot pinpoint with 100% accuracy the source of the activity
-The electrodes used in ERPs may be placed on the scalp inaccurately or move during recording, leading to unrepresentative results

Question 8

Post mortem examinations

Answer 8

-Post mortem examinations involving analysing the brain after death to examine abnormal brain structures, this is usually done on individuals with unusual brain disorders e.g HM
-This can help to identify brain areas linked to specific behaviours or deficits

Question 9

Post mortem examinations Evaluations

Answer 9

+ With post mortem examinations, researchers are able to study the brain without harming any living participants
+Post mortem examinations have led to the discovery of key areas of the brain e.g Broca’s area and Wernicke’s area
-Causation cannot be confirmed- behaviour may not be caused by damage
-Ethical concerns; consent is required before the post mortem examination and this is not always possible to acquire