Ways of Investigating the Brain Flashcards
Name 4 ways of imaging the brain
FMRI –EEG –ERPs -Post mortem examinations
What is a FMRI?
A method used to measure brain activity while a person is performing a task that uses MRI technology (detecting radio wave from changing magnetic fields) it allows us to tell which regions of the brain are rich in oxygen and therefore active
Outline FMRIs as a way of investigating brain functions
It monitors blood flow and oxygenation in the brain, as areas become more active they require more oxygen (haemodynamic response). It produces 3d images of which areas are most active –helps understanding of localisation of function
Outline strengths and weaknesses of FMRI scans as a way of investigating of brain functions
(+) Good spatial resolution and low radiation - risk free and non-invasive
(-) Bad temporal resolution and cannot hone in on neural activity and people have to lay still
What is an EEG?
A record of tiny electrical impulses produced by brain activity, by measuring brain patterns certain conditions of the brain can be measured/diagnosed e.g. epilepsy
Outline EEG’s as a method for investigating brain function
Electrodes are fixed to an individuals scalp via a skull cap they record info of brainwave patterns and are used to diagnose tumours, disorders etc.
Outline strengths and weaknesses of EEG’s as a way of investigating brain functions
(+) good for fast, accurate diagnostics and high temporal resolution
(-) The information received is a generalised overview of the whole brains activity - it doesn’t allow you to pinpoint specific neurons etc.
What is an ERP?
The brain’s electrophysiological response to a specific sensory, cognitive or motor event can be isolated through statistical analysis of EEG data
Outline ERP’s as a method for investigating brain function
Statistical averaging techniques allows us to hone in on the specific functioning of specific neurons resulting from a stimulus. We can filter out irrelevant neural responses that were present in EEG’s. Allows us to associate neurons with processes.
Outline strengths and weaknesses of ERP’s as a way of investigating brain functions
(+) Far more specific than ERP’s and high temporal resolution
(-) Lack of standardisation in ERP methodology for different studies cast doubt over findings and For pure ERP data extraneous noise/material must be eliminated - not always easy
What are post-mortem examinations?
The brain is analysed after death to determine whether certain observed behaviours during the patients lifetime can be linked to abnormalities in the brain
Outline post-mortem studies as a way of investigating the function of the brain
Post-mortem studies are usually of ppl who had a rare disorder - areas of brain damage are examined after death to establish the likely cause of the problem - may use comparisons with ‘typical brains’
Outline strengths and weaknesses of post-mortem studies as a way of investigating brain functions
(+) provided a foundation for early understanding of key processes and improve medical knowledge and help generate hypotheses for further study
(-) It’s difficult to prove causation - damage may be linked to other unknown issues and there are ethical issues of consent, was it truly ‘informed’?
