Lesson 10 ways of studying the brain Flashcards
(18 cards)
What are the ways of studying the brain?
fMRI
Post-mortem examination
Electroencephalogram
Event-related potentials
What does an fMRI provide?
An indirect measure of neural activity
What does an fMRI use?
Magnetic fields and radio waves to monitor blood flow in the brain
What does an fMRI measure?
The change in the energy released by haemoglobin reflecting activity of the brain (oxygen consumption) to give a moving picture of the brain
Strengths of an fMRI
Captures brain dynamic brain activity as opposed to a post-mortem examination which purely show the physiology of the brain
Have good spatial resolution
Weaknesses of an fMRI
Interpretation of fMRI is complex and is affected by poor temporal resolution, biased interpretation and by the base line task used
fMRI research is expensive leading to reduced sample sizes which negatively impact the validity of the research
What does an EEG provide?
A direct measure of general neural activity
How is an EEG carried out?
Electrodes are placed on the scalp and they detect neuronal activity directly below where they are placed
What is an EEG pattern?
When electrical signals from the different electrodes are graphed over a period of time
Strengths of EEG
Useful in clinical diagnosis for epilepsy
Cheaper so can be used more widely in research
High temporal resolution
Weaknesses of an EEG
Poor spatial resolution
What do event-related potentials provide?
A direct measure of neural activity in response to a specific stimulus introduced by the researcher
How are event-related potentials carried out?
Stimulus is presented many times
Responses are averaged together
Any extraneous neural activity that is not related to the specific stimulus will not occur consistently, whereas activity linked to the stimulus will
Strengths of an ERP
Cheaper than an fMRI so can be used more widely in research
Have good temporal resolution
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
Weaknesses of ERP
Have poor spatial resolution
Only strong voltage charges generated across the scalp are recordable, important electrical activity occurring deeper in the brain is not recorded.
How are post-morgen examinations carried out?
When a person dies, psychologists look for abnormalities in the brain that might explain their behaviour
Strengths of post-mortem examinations
Allow for more detailed examination of anatomical and neurochemical aspects of the brain
Weaknesses of post-morgen examination
May lack validity because people die in a variety of circumstances and at varying stages of disease. The length of time between death and the post-mortem and drug treatments can all affect the brain
Have a very small sample sizes so cannot be representative of the target population and so it is problematic to generalise the findings to the wider population
