4 - Ways Of Studying The Brain Flashcards
When might the brain be studied?
- Investigating illness
- Completing psychological research
What was the traditional way of studying the brain?
Post mortems
Why has the way of studying the brain changed?
Advances in technology has produced 3 new ways, with more focus on brain scanning
What are the four ways of studying the brain?
- Post mortems
- FMRIs (Functional Magnetic Resonance Imaging)
- EEGs (Electroencephalogram)
- ERPs (Event-related potentials)
What are post mortems?
Analyse the internal structures of the brain (e.g. limbic system) after death
When are post mortems usually used?
When studying an individual who had a rare disorder, to see if brain damage or structural differences (when compared to a neurotypical brain) may have caused this
What is good about post-mortems?
- Can look at internal structures (e.g. limbic system)
- Vital in laying foundations for understanding the brain (e.g. Broca + Wernicke, who couldnt use scans)
What is bad about post-mortems?
- Ethical issue of lack of informed consent, as they may not have given it before death (e.g. HM didn’t give consent - unethical)
What are fMRIs?
Analysing brain activity when a task is being performed, using radio waves
Outline how fMRIs work
- Radio waves from changing magnetic fields (changes in blood oxygenation and flow) are detected
- These changes are result of changes in brain activity
- When brain is more active: consumes more oxygen
- When brain is more active: greater blood flow to deliver this oxygen
- The detected changes are displayed in 3D images: activation maps
What are activation maps?
The 3D images of brain activity in fMRIs
- Detailed
- High spatial resolution
When may fMRIs be used?
When studying localisation of function during a certain task
What is good about fMRIs?
- Safer than other scanning techniques (don’t involve radiation)
- Activation maps are detailed with high spatial resolution
What is bad about fMRIs?
- Poor temporal resolution (5 sec time lag between image on screen + neural activity, so don’t represent moment-to-moment brain activity)
- Comparatively expensive
What are EEGs?
Record of tiny electrical impulses produced by brain activity
What equipment is used in EEGs?
Electrodes are fixed to the head using a skull cap to measure brain’s electrical activity (patterns from neurones)
Why may EEGs be used?
To diagnose disorders in the real world
What rhythm from EEGs may indicate neurological abnormalities?
Arrhythmic activity patterns (no rhythm)
- E.g. epilepsy, sleep disorders
What is good about EEGs?
- High temporal resolution (1millisec delay or less, useful in moment-by-moment activity study)
What is bad about EEGs?
- General measure (measures neurones throughout whole brain, rather than pinpointing brain activity to show root of localised issues)
What are ERPs?
Statistically analysing EEG data to isolate the brain’s response to a particular event
How do ERPs focus on a particular event?
- Uses statistical averaging to remove extraneous brain activity from regular EEG recordings
- This isolates the response to a specific stimulus/task
Why may ERPs be seen as better than EEGs?
Can show a response to a specific task, rather than general overview of neural activity
What is good about ERPs?
- Good qualities of EEGs (i.e. high temporal resolution)
- More specific, looking at a particular event
What is bad about ERPs?
- Lack of standardisation in the method of using statistical averaging to remove extraneous brain activity, so hard to create reliable conclusions (that can be repeated)
