biopsychology - investigating the brain. Flashcards
What is meant by invasive?
Involves entering the skull.
What is meant by non-invasive?
Does not involve entering the skull.
What are the different ways to investigate the brain?
- functional magnetic resonance imaging (FMRI).
- electroencephalogram (EEG).
- event-related potentials (ERPs).
- post-mortem examinations.
What is meant by functional magnetic resonance imaging (FMRI)?
A brain scanning technique that measure blood flow and oxygen in the brain.
What is meant by electroencephalogram (EEG)?
A brain scanning techniques that measures electrical activity through electrodes attached to the scalp.
What is meant by event-related potentials (ERPs)?
A brain scanning technique using electrodes that are attached to the scalp.
What is meant by post-mortem examinations?
The analysis of a person’s brain following their death.
What occurs during a functional magnetic resonance imaging (FMRI) scan?
- if a brain area becomes more active there is an increased demand for oxygen in that area.
- brain responds by increasing blood flow to that area known as haemodynamic response.
- maps can then be produced to show which areas of the brain are involved in a certain mental activity.
- creates a dynamic 3D image of the brain highlighting which areas are involved in different neural activities.
What occurs during a electroencephalogram (EEG) scan?
- information is passed in the brain as electrical activity in the form of electrical impulses transmitted along neurones.
- small electric charges are detected by electrodes and are graphed over a period indicating the level of activity in the brain.
Who are electroencephalogram (EEG) scans used by?
Often used by clinicians as a diagnosis tool as arrhythmic patterns indicate neurological abnormalities such as epilepsy, sleep disorders or tumours.
What occurs during a event-related potentials (ERPs) scan?
- stimulus is presented to a participant and the researcher looks for activity related to that stimulus.
- difficult to separate from all the EEG data where the stimulus is presented many times and an average response is graphed.
- reduces any extraneous neural activity which means the specific response to the stimulus stand out known as ‘averaging’.
What occurs during a post-mortem examination?
Examine for abnormalities that might explain a particular behaviour.
Why may post-mortem examinations be used?
To establish the underlying neurobiology of a behaviour.
What are the weaknesses of using functional magnetic resonance imaging (FMRI)?
- uncomfortable gear.
- having to stay still for 45 mins may make it more difficult for the participant to stay still which could result in movement reducing the validity of the results.
- expensive.
- clear image can only be captured if participant stays perfectly still.
- only measures blood flow in the brain therefore not a direct measure of neural activity in certain brain areas.
- no quantitative measure of mental activity in these areas of the brain.
- overlooks the nature of brain activity focusing only on localised activity.
What are the strengths of using functional magnetic resonance imaging (FMRI)?
- non-invasive.
- no exposure to potentially harmful radiation to the brain.
- more objective and reliable measure of psychological processes than verbal reports.
- allows us to investigate cognitive mental processes that cannot be described through verbal reports.
- very high spatial resolution images.
- shows how the brain activity is localised.
- depicts very small details.
What are the strengths of using electroencephalogram (EEG)?
- high temporal resolution
- recording of brains activity in real time therefore particular tasks can be measured associated with the brain.
- useful in clinical diagnosis.
What are the weaknesses of using electroencephalogram (EEG)?
- only detects activity in superficial regions of the brain.
- cannot reveal what is happening in the deeper regions.
- electrical impulses can be picked up by several neighbouring electrodes therefore EEG signal is not useful in pinpointing the exact source of an activity.
What are the weaknesses of using event-related potentials (ERPs)?
- time consuming.
- uncomfortable
- electrodes are attached to the scalp resulting in unrepresentative readings as the patient’s discomfort may be affecting cognitive responses to situations.
- hard to establish pure data.
- background noise and extraneous material must be completely eliminated.
What are the strengths of using event-related potentials (ERPs)?
- non-invasive.
- more specificity on the measurement of neural processes compared to raw EEG data.
- high temporal resolution
- derived from EEGs.
- eliminates extraneous neural activity that other techniques may struggle to do.
What are the strengths of using post-mortem examinations?
- allows for deeper regions to be researched of anatomical and neurochemical aspects of the brain.
- foundation to understand key processes in the brain.
- broca and wernicke both relied on this method to establish links between language and brain behaviours long before neuroimaging techniques were developed.
- improve medical understanding.
- help in generation of hypotheses for further research.
What are the weaknesses of using post-mortem examinations?
- invasive.
- people die in a variety of circumstances at varying stages of disease and these factors can influence post-mortem studies.
- limited as person is dead
- unable to follow up anything that arises due to the post-mortem concerning possible relationship between brain abnormalities and cognitive functioning.
