ways of studying the brain Flashcards
biopsychology
What are the 4 techniques used to study the brain?
fMRI- functional magnetic resonance imaging
EEG- electroencephalogram
ERP- event related potentials
Post-mortem examinations
What is an fMRI?
Scans that work by detecting which areas of the brain are most active by picking up on blood oxygenation. When part of the brain is more active, it uses more oxygen therefore, fMRI’s can see which areas of the brain are active during different tasks. It creates 3D images allowing us to understand localisation of function
What are the strengths of fMRI?
Non-invasive - they don’t require any surgery or painful/dangerous procedures
High spatial resolution - show a clear image in great detail helping to identify localisation of function
What are the limitations of fMRI?
Expensive - around £500 per scan which can affect researchers doing studies on larger sample sizes
Poor temporal resolution- a delay of about 5 seconds in presenting the image
What is an EEG?
Electrodes attached to a skull cap placed on the scalp. They monitor electrical activity in the brain as the electrodes pick up on brainwaves produced due to electrical impulses firing across neurons. Measures activity in states such as arousal or sleeping
What are the strengths of EEG?
Cheaper - can be utilised more frequently
High temporal resolution - can detect brain activity at a millisecond speed
What are the limitations of EEG?
Poor spatial resolution - can only pick up on electrical activity in the outer regions
Electrical activity is often detected simultaneously across several regions so it’s difficult to distinguish the exact area of the brain that is responsible for this activity
What is an ERP?
Can be used when we want to find out about brain activity in response to certain stimuli/ a certain task. EEG scan first and activity associated with specific stimuli is picked out, called averaging. Put on a graph to investigate internal processes such as attention and perception
What is a sensory EPR?
Early waves, within the first 100 milliseconds of exposure
What is a cognitive ERP?
the later waves, once a person has had chance to mentally process the stimuli
What are the strengths of ERP?
Cheaper - can be utilised more frequently
High temporal resolution - can detect brain activity at a millisecond speed
What are the limitations of ERP?
Poor spatial resolution - can only pick up on electrical activity in the outer regions
Electrical activity is often detected simultaneously across several regions so it’s difficult to distinguish the exact area of the brain that is responsible for this activity
What is a Post-mortem examination?
Dissecting the brain of a deceased person to find neural reasons for their behaviours. Typically, the person would have displayed a particular behaviour whilst alive giving the researcher an opportunity to fin its neural cause
What are the strengths of Post-mortems?
More in depth examinations - see the structure of the brain first hand
Learned a lot through this method - E.g. we know about Broca’s area because he did a post-mortem
What are the limitations of Post-mortems?
Cause and effect cant be determined - unable to manipulate variables
Ungeneralisable - small sample size as not an endless supply of brains have been donated and informed consent cannot always be given
