Ways of studying the brain Flashcards
FMRIs
Functional Magnetic Resonance Imaging. Detects changes in blood oxygen levels and blood flow that occur due to neural activity in specific parts. Haemodynamic response - More active area in the brain consumes more oxygen so more blood flow to that area. Produce 3D maps showing what part of the brain is involved in what mental process (activation maps). Important for localisation of function.
EEGs
Electroencephalogram. Measures electrical activity within the brain via electrodes on skull cap of patient. Brainwave patterns are generated to represent activity of thousands of neurones producing overall account of brain activity. Used by clinicians in diagnostics. Arrhythmic patterns can indicate epilepsy, tumours and other neural abnormalities.
ERPs
Event related potentials. EEG data represents overall brain activity. Use statistical averaging to remove extraneous brain activity from the original EEG. Only response caused by a specific stimulus is shown. Different ERPs relate to different cognitive processes.
Post Mortem Examinations
Analysis of brain following death. Usually people with rare disorders and experienced unusual defects. Cn involve comparing damaged aras with those of a neurotypical brain. Used to establish cause of affliction
Post Mortem evaluation
+ Broca and Wernicke relied on post mortems. Ground breaking. HM case study. Post mortems provided useful and accurate evidence before neuroimaging was possible.
- Informed consent. Person is dead. Not widely accessible. Correlation does not equal causation.
ERPs evaluation
+ More specific than EEGs. High temporal resolution. Used to measure cognitive factors and defects such as attention allocation and working memory.
- Lack of standardisation in methodology between studies. Difficulty in completely removing extraneous variables. Not achievable and if so difficult.
EEGs evaluation
+ Used in studying sleep cycles and diagnostics. Epilepsy, random bursts pf activity in the brain. High temporal resolution 1 millisecond. Real world application and high accuracy.
- Generalised nature of ‘overall’ brain activity. Not useful in pointing to source of neural activity (low spatial) resolution. Cannot differential between activity in different areas.
FMRIs evaluation
+ No radiation. Risk free. Non invasive. Easy to use. High spatial resolution. Can pinpoint activity to the millimetre. Very clear image of how brain is localised. Safe and highly accurate.
- Expensive compared to other neuroimaging techniques. Poor temporal resolution 5 second lag. Cannot accurately capture brain activity in that one moment.
