Biopsychology - Ways Of Investigating The Brain Flashcards
What are the 4 different ways to investigate the brain?
fMRIs
EEGs
ERPs
Postmortem examinations
What is a MRI?
Magnetic resonance imaging
What does a MRI do?
Uses a strong magnetic (makes the hydrogen atoms in the water molecules in the body align up) to take a static image of the brain
What is a fMRI?
Functional magnetic resonance imaging
How does a fMRI work?
Similarly to an MRI but detects the changes blood oxygenation & flow due to neural activity in the brain. If the brain area is more active it consumes more oxygen so the blood is directed to the area.
What do fMRIs tell us?
Shows which parts of the brain are involved in a particular mental process which has an important implication for our understanding of localisation of function
What does an EEG stand for?
An Electroencephalogram
What is an EEG?
A record of the tiny electrical impulses produced by brain activity
How is brain activity measured using an EEG?
Electrodes that are fixed onto the individual’s skull using a skull cap
What are EEGs used for?
Diagnosing disorders e.g. epilepsy, tumours & sleep disorders
What are the 4 types of EEG?
Alpha
Beta
Theta
Delta
What does an alpha EEG show?
Light sleep
What does a delta or theta EEG show?
Deep sleep
What is amplitude?
The intensity of the size of activity
What is frequency?
The speed or quantity of activity
What are the 2 distinctive states produced by an EEG?
Synchronised
Desynchronised
What is a synchronised EEG?
A recognisable waveform
What is a desynchronised EEG?
No pattern shown
What are the strengths of using a fMRI?
Non invasive, no risks as no radiation is used & straightforward to use
Good spatial ability (produces good images)
What are the limitations of using a fMRI?
Expensive
Can only work if the individual stays completely still (difficult for children)
Poor temporal resolution (has a 5 second lag) -> misses information
Measures blood flow in the brain but cannot home in on the activity of individual neurons
What are the strengths of using an EEG?
Valuable for the diagnosis of epilepsy as bursts of electrical activity will appear on the screen)
Contributed to the knowledge of sleep stages
High temporal resolution as it can detect brain activity in a single millisecond
What are the limitations of using an EEG?
Low spatial resolution as the information is generalised you cannot pinpoint the exact source of neural activity
What does ERP stand for?
Event-related potentials
What are ERPs?
Measures electrical activity in the bran similar to an EEG but uses a stimulus to measure the brain activity related to that stimulus which is repeated many times & averaged
