L9 - Studying the Brain Flashcards
When are post-mortems used
After a patient who displays an abnormality dies
What do PMs involve
Dissecting the brain and looking at differences to certain parts to form explanations
+ of PM
Can study brain parts (anatomical and neurochemical) too deep for MRI in detail, e.g. hypothalamus, unlike others
- of PMs
Sample sizes are often small
Time between death and PM, drug treatments can affect the brain
Reasons/stage of disease can also affect
Functional Magnetic Resonance Imaging uses what
Magnetic fields and radio waves to measure brain blood flow
fMRI blood flow is monitored by measuring what
Changes in energy related by Hb, reflecting oxygen consumption and brain activity
fMRIs involve brain activity bring compared
During a baseline task and during a specific activity
+ of fMRI
Shows dynamic brain activity not just physiological aspects unlike MRI/PMs which show just physiology
- of fMRIs
Complicated interpretation affected by bias of interpretation/baseline task/temporal resolution
Expensive so sample size is small, affecting validity and generalisation
Describe electroencephalograms
Electrodes placed on the scalp to detect neuronal activity
Measures general electrical activity
How is an EEG pattern made
Electrical signals from different electrodes are graphed
Epilepsy shows spikes for example
+ of EEGs
Used in clinical diagnosis to confirm a condition, e.g. if their EEG matches epilepsy EEG
Cheaper than fMRIs, can be more widely used
- of EEGs
Poor spatial resolution since they can’t measure the entirety of the brain surface, can’t measure v small parts of the brain surface
Describe Event-Related Potentials (ERPs)
Small voltage changes in the brain triggered by specific events and stimuli
In ERPs, the stimulus has to be presented
Several times to discount activity unrelated to the stimulus (will be inconsistent)
