Ways to Study the Brain Flashcards
1
Q
Post-Mortem examinations
A
- Means after death.
- Used to establish underlying neurobiology of a particular behaviour. - researchers may study a person who displays an interesting behaviour while they are alive that might suggest underlying brain damage.
- When the person dies, the researchers can examine the brain and seek abnormalities that may explain behaviour.
- Most common type is histology - parts of interest in dead brain are cut into thin slices and studied under microscopic slides.
2
Q
Broca’s work
A
- Tan displayed speech problems when he was alive and it was found that he had a lesion in the area of the brain known as Broca’s area which is important for speech production.
3
Q
Evaluation of Post Mortem Examinations - Useful Tool
A
- Direct study of brain tissue allows detailed investigation at the level of neurons, synapses and neural circuits.
- Enables researchers to examine deeper regions of the brain - hypothalamus.
- Researchers have discovered structural abnormalities of brain and found evidence of changes in neurotransmitter systems, both associated with Schizophrenia.
- Strength - improve medical knowledge and help generate hypotheses for further study.
4
Q
However - useful tool
A
- Not a common idea to donate brain for psychological research.
- Research relies on donation of brains and in the case of particular people with brain damage, sometimes wait years before brain becomes available.
- Weakness - may slow down scientific progress.
5
Q
Evaluation of Post Mortem Examinations - confounding influences
A
- As people die in a variety of circumstances and at varying stages of disease - influence post mortem brain.
- Length of time between death and post mortem and age at death must be considered.
- Weakness - confounding influences make comparing cases with controls difficult.
- As the person is already dead the researcher is unable to follow up on anything that may arise from post mortem concerning link between brain abnormality and cognitive functioning.
- Weakness - researchers can only make assumptions on relation and lacks adequate experimental control.
6
Q
FMRI - functional magnetic resonance imaging
A
- Developed from og MRI scanner and is used for measuring changes in brain activity while person is performing a task.
- Neurons most active during a given task will use more energy - requires glucose and oxygen carried in the bloodstream.
- Technique measures blood flow in brain using radio waves and magnetic field.
- If an area becomes more active - increased demand for oxygen.
- Brain responds to demand by increasing blood flow, delivering oxygen in red blood cells.
- Researchers able to produce maps showing which areas of the brain are involved in a particular mental activity.
- Scanner takes photo of areas of high oxygen before a task and again during a task - difference is only to do with activity.
7
Q
Evaluation of FMRI - Non Invasive
A
- Unlike other imaging techniques which require harmful injections of radioactive material.
- If administered correctly, straightfoward to use and can produce images which have high spatial resolution.
- Strength - can provide a clear picture of how brain activity is localised - risk free.
8
Q
However - non invasive
A
- Focuses on localised brain activity - critics argue that networked nature of brain is overlooked.
- Argue that it is the communication between brain regions that is most critical to mental function.
- Weakness - could mean it ignores how brain functions as a whole.
9
Q
Evaluation of FMRI - Objective
A
- More objective and reliable way of measuring psychological processes.
- Useful way of investigating phenomena that people would not be capable of providing in verbal reports.
- Strength - compared to more traditional questionnaire methods it is more scientific.
10
Q
However - Objective
A
- Not a direct measure of neural activity.
- Only measures changes in blood flow.
- Means it cannot home in on activity of individual neurons and it can be difficult to tell exactly what kind of brain activity is seen on screen.
- Weakness - not a truly quantitative measure of mental activity.
11
Q
EEG - Electroencephalogram
A
- Measures electrical activity in the brain.
- Electrodes placed on scalp detect small electrical charges resulting from activity of brain cells,
- Electrical signals from electrodes are displayed over a period of time - resulting in a representation called EEG.
- Data can be used to detect various types of brain disorder or to diagnose other disorders that influence brain activity such as Alzheimers.
- Readings of patients with epilepsy show spikes of electrical activity - slow electrical activity.
12
Q
Evaluation of EEG - Real Time Recording
A
- Rather than a still image of a passive brain, they provide real time recording of the brain activity.
- Means the researcher can accurately measure brain activity.
- Strength - unlike fMRI, EEG technology can accurately detect brain activity at a resolution of a single millisecond.
13
Q
However - Real Time Recording
A
- Due to generalised nature of the information received, activity can be picked up by several neighbouring electrodes therefore EEG signal is not useful for pinpointing exact source of activity.
- Weakness - means researchers find it difficult to distinguish between activities originating in different but nearby regions of the brain.
14
Q
Evaluation of EEG - Clinical Diagnosis
A
- EEGs can pick up on disturbed brain activity associated with epileptic seizures which is helpful in diagnosing epilepsy.
- Also contributed much to our understanding of the stages involved with sleep.
- Strength - proved invaluable diagnosis of many conditions.
- Less invasive as no radiation is used and no instruments inserted into body.
- Strength - risk free and patients under less stress.
15
Q
However - Clinical Diagnosis
A
- Electrodes can be uncomfy - may affect readings taken if patient is affected.
