Investigating the brain Flashcards
fMRI (Functional Magnetic Resonance Imaging)
This works by detecting changes in the blood oxygenation levels and flow as a result of neural activity in the brain. When a brain are is more active it consumes more oxygen and blood flow is directed in that area.
This produces 3D images showing which parts pf the brain are involved in a particular mental process helping understand brain localisation.
EEG (Electroencephalogram)
This measures electrical activity within the brain via electrodes that are fixed to an individual’s scalp using a scull cap. The scan records brainwaves generated from neurons. This can be used to help diagnose epilepsy, tumours or sleep disorders.
ERP (Event Related Potentials)
These are wave pattern data from EEGs which change in response to a stimulus. If a stimulus is present, it produces a specific change in a wave pattern.
Post-Mortem examination
Involves dissecting the brain of a person who has died. This allows an investigation into the internal structure of the brain.
Example of Port-Morten examination
Brown et al (1986) used this to show that patients who had suffered from schizophrenia had enlarged ventricles in their brain.
Example of ERP
Miltner et al (2000) 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 et al (2008) showed that patients suffering from schizophrenia displayed an abnormal brain wave patterns compared to a control group.
Example of MRI
Shegrill et al (2001) 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.
