ways of studying the brain Flashcards
What are the 4 main scanning techniques
- fMRI (functional magnetic resonance imaging)
- ERP (event-related potentials)
- EEG (electroencephalogram)
- Post-mortem examinations
What is spatial resolution
Refers to the smallest feature (or measurement) that a scanner can detect, and is an important feature of brain scanning techniques. Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy.
What is temporal resolution
Refers to the accuracy of the scanner in relation of time: or how quickly the scanner can detect changes in brain activity.
What is fMRI (functional magnetic resonance imaging)
Braining scanning technique that measure blood flow in the brain as a result of neural activity
- Must lie still and flat whilst head being scanned
- Creates a moving 3D map of brain
What are the strength of fMRI
• Good spatial resolution (1- 2mm)
• Non-invasive and do not use radiation (risk free)
• Can measure brain activity linked to events/tasks.
What are the weaknesses of fMRI
- Poor temporal resolution – (detects activity in 1-4 seconds)
- Expensive- leading to low sample size
- Interpretation is complex
- Requires removal of metal objects (not suitable for
people with pacemakers) - Unsuitable for people with claustrophobia
What is EEG (electroencephalogram)
• EEGs use electrodes fixed to a participant’s scalp which detect neuronal activity directly below where they are placed
• Small electrical charges that are detected by the electrodes are graphed over a period of time, indicating the level of activity in the brain.
What are the strengths of EEG
Cheaper than fMRI’s – allows for large sample size
• High temporal resolution (detects activity in 1-10ms)
• Useful in diagnosis of epilepsy
What are the weaknesses of using EEG
• Poor spatial resolution (superficial general regions only) – lacks precision /electrodes not sensitive enough,
what are ERP (event related potentials)
- ERPs use electrodes fixed to a participant’s scalp to detect brainwaves
- Different to EEG in that - a stimulus is presented to a
participant (for example a picture/sound) and the
researcher looks for activity related to that stimulus.
what are the strengths of ERP
• Good temporal resolution detects activity in 1-10ms)
• Cheaper than fMRI’s – allows for large sample size
• Non-invasive & no radiation risk
• Can measure brain activity linked to events/tasks
What are the weaknesses of ERP
Poor spatial resolution (superficial general regions only)
• Lack of standardisation
• In order to establish pure data- extraneous variables must be
controlled which is difficult.
What are post mortems examinations
- Researchers study the physical brain after death of a person who displayed a particular behaviour while they were alive that suggested possible brain damage.
- Broca used this method to discover which area of the brain is important for speech production
What are the strengths of post mortem exam
• Enables deeper regions of the brain to be investigated than non-invasive techniques
• Was vital in providing a foundation for early understanding of key
processes in the brain
What are the weaknesses of post mortem exam
• Ethical issues/ special permission needs to be granted- small sample sizes
• Can be affected by changes which occur during/after death
• Can’t investigate brain activity during specific tasks/ activities
