Ways of studying the brain Flashcards
What are the ways of studying the brain?
-Functional magnetic resonance imaging
-Electrencephalogram
-Event-Related potentials
how does fMRI work?
-Indirectly measures electrical activity of neurons by recording changes
in brain blood flow while a person completes a cognitive task.
-As a particular area of the brain becomes more active, it requires more
oxygen, which is supplied via bloodstream.
• As the blood becomes deoxygenated its magnetic properties change.
• The difference in magnetic properties is detected by applying radio
waves to the brain which is converted into a computer image.
• A stable radio wave signal indicates more blood flow and therefore
high neural activity: these active areas appear as bright colours to give
a moving image of the brain
How do EEG’s work?
-Electrodes placed on the scalp.
-electrodes directly measure electrical activity of neurons on the surface of the brain.
-They continually measure neural activity during brain states such as sleep and arousal.
• Electrical signals from different electrodes are recorded over an extended period of time to produce an EEG graph.
How do ERP’s work?
-Electrodes placed on the scalp.
-electrodes directly measure electrical activity of neurons on the surface of the brain.
• ERPs are very small changes in electrical activity of the brain triggered by specific stimuli presented to the participant (e.g. a sound or flashing light).
-Many EEG readings are taken whilst the same stimulus is presented and an average reading is calculated.
• A consistent neural response to the stimulus will appear as a clear ERP. Any inconsistent, extraneous background
neural activity (‘noise’) will be filtered out
How do post morton examinations work?
-Involves the analysis of a person’s brain after their death.
-If a person had a rare disorder or displayed abnormal behaviour during their lifetime, a post-mortem may establish the neurobiological cause.
-Comparisons to neuro-typical brains may also be used to ascertain
the extent of the differences.
-A famous post-mortem was carried out on Louis Leborgne. This revealed extensive damage to his Broca’s area, which was linked to his inability to produce speech except for the nonsense word “tan”.
