Investigating the brain Flashcards
(24 cards)
What is an fMRI (Functional Magnetic Resonance Imaging)
Functional Magnetic Resonance Imaging
How does an fMRI work
Detecting changes in the blood oxygenation levels and flow as a result of neural activity in the brain.
How to read fMRI
When a brain are is more active it consumes more oxygen and blood flow is directed in that area.
What does an fMRI produce
3D images showing which parts pf the brain are involved in a particular mental process helping understand brain localisation.
What is an EEG
Electroencephalogram
How does an EEG work
Measures electrical activity within the brain through a scan recording brainwaves generated from neurons.
What do EEGs do
Help diagnose epilepsy, tumours or sleep disorders.
What is an ERP (name)
Event Related Potentials
What is an ERP (physically)
Wave pattern data from EEGs which change in response to a stimulus.
How to read ERP
If a stimulus is present, it produces a specific change in a wave pattern.
What is a Post-Mortem examination
Dissection of the brain of a person who has died.
What does a Post Mortem examination allow
Investigation into the internal structure of the brain.
Example of Port-Morten examination (Brown)
Brown used this to show that patients who had suffered from schizophrenia had enlarged ventricles in their brain.
Example of ERP (Miltner)
Miltner found that people with phobias had a greater amplitude wave in response to images of objects they feared compared to phobic individuals.
Example of EEG (Boutros)
Boutros showed that patients suffering from schizophrenia displayed an abnormal brain wave patterns compared to a control group.
Example of MRI (Shegrill)
Shegrill used this to shows which areas of the brain were active during hallucinations in a patient which schizophrenia.
Strengths of fMRI
They do not rely on the use of radiation.
They are risk free and non-invasive.
They have high spacial resolution with details to the millimetre.
Weaknesses of fMRI
They are expensive.
They can only get a clear image if the person stays completely still.
It has poor temporal resolution because of the 5 second lag between the screen and the firing of the neurons.
Strengths of EEG
The help to diagnose conditions such as epilepsy.
They help to understand stages involved in sleep.
Technology has extremely high temporal resolution.
Weaknesses of EEG
They are often generalised information meaning the source of activity can’t be pinpointed.
They do not distinguish between activity originating in different locations of the brain.
Strengths of ERP
Bring more specificity to measurements.
They have excellent temporal resolution.
It helps the widespread use in the measurement of cognitive functions.
Weaknesses of ERP
A lack of standardisation means findings cannot be confirmed.
To establish pure data, extraneous material must be eliminated, which isn’t easy.
Strengths of Post-Mortem exams.
Provides a foundation for early understanding of key brain processes.
Establishes links between language, brain, and behaviour.
Weaknesses of Post-Mortem exams.
Causation is an issue.
Damage in the brain may not be linked to deficits under review but to some unrelated trauma.
