bio-psych - ways of studying the brain Flashcards
strengths of FRMI
Produces images that have high spatial resolution, depicting detail by the millimeter, and providing a clear picture of how brain activity is localized
It does not rely on radiation and is therefore virtually risk-free, non-invasive and straightforward
explain FMRI scanning?
Functional magnetic resonance imaging (fMRI) is a brain-scanning technique that measures blood flow in the brain when a person performs a task.
fMRI works on the premise that neurons in the brain that are the most active (during a task) use the most energy.
An fMRI creates a dynamic (moving) 3D map of the brain, highlighting which areas are involved in different neural activities.
what are the weaknesses of FMRI scanning?
It can only measure blood flow in the brain, it cannot home in on the activity of individual neurons and so it can be difficult to tell exactly what kind of brain activity is been represented on the screen
Expensive compared to other neuroimaging techniques and can only capture the image if someone stays perfectly still
Poor temporal resolution because there is around a 5 second lag behind the image on the screen and initial neuronal firing
explain what an EEG is?
An electroencephalogram (EEG) works on the premise that information is processed in the brain as electrical activity in the form of action potentials or nerve impulses, transmitted along neurons. EEG measure this electrical activity through electrodes attached to the scalp. Small electrical charges that are detected by the electrodes are graphed over a period of time, indicating the level of activity in the brain.
stregnths of EEGs
Safe way of measuring brain activity, there is no surgery
used as a diagnostic tool eg epilepsy
Helps to identify activity in various regions of brain
weakness of EEGs
Generalized nature of the information received
explain what is an ERP?
Event-Related Potentials (ERP) use similar equipment to EEG, i.e. electrodes attached to the scalp.
However, the key difference is that a stimulus is presented to a participant (for example a picture/sound) and the researcher looks for activity related to that stimulus.
stregnths of an ERP?
Excellent temporal resolution and has led to their widespread use in the measurement of cognitive functions and deficits
Addresses limitations of EEG. These bring more specify to the measurement of the neural processes
weakness of an ERP?
In order to establish pure data, background noise and extraneous material must be completely eliminated, and this is not easy to achieve
Outline one difference between the EEG and ERPs
EEGs measure general electrical activity in the brain whereas ERPs involve the patient to be presented with a stimulus material and then the corresponding brain electrical activity is measured
what is a post mortem examination?
The brain is analysed after death to determine whether certain observed behaviours during the patient’s lifetime can be linked to abnormalities in the brain Individuals whose brains are subject to post mortem are likely to be those who have a rare disorder and have experienced unusual deficits in mental functioning.
Areas of damage within the brain are examined as a means of establishing the likely cause of the affliction the person suffered. This may involve a comparison with a neurotypical brain in order to ascertain the difference.
strengths and weaknesses of post mortem examinations?
Strengths
We improved medical knowledge before brain scanning technology was available
Weaknesses
Although consent is given prior to death, If we are looking at individuals with impaired mental is functioning it is not informed consent
After death, brains start to decay and therefore causation is an issue as natural decay could be assumed to be the cause of problems diring life eg speech production
