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ways of studying the brain - Coggle Diagram
ways of studying the brain
post -mortem examinations
brain examined after death to try and correlate structural abnormalities/damage to behaviour
evaluation
strength- PM evidence vital in early understanding of brain processes including identification of Broca&wenickes area and linking language and the brain. improved medical knowledge of brain so beneficial to psychology as allowed for hypothesis to be generated
limitation- PM evidence lacks validity and generalisability as rely on small sample sizes.raise ethical issues of consent as special per mission needs to be granted to conduct PM. not many ppl give permission meaning problems with getting large enough sample size
brain compared to 'normal' brain to identify differences
allows psychologists to look at anatomical structures and identify brain areas
key terms
temporal resolution
refers to accuracy of the scanner in relation of time: how quickly the scanner can detect changes in brain activity
non-invasive
no insertion of instrument or radiation into the body or brain
spatial resolution
refers to the smallest feature (or measurement) that a scanner can detect. greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy
FMRI
functional magnetic resonance imaging
measures changes in brain activity while a person performs a task
detects changes in blood oxygenation and flow that indicate increased neural activity
produce 3D moving images of the persons brain
able to produce maps showing which areas of the brain involved in a particular activity
evaluation
strength- good spatial resolution so psychologists able to determine brain regions with good accuracy and able to see where different functions happen and what parts of brain are activated in particular mental processes. allows for conclusions to be made on localisation of function
limitation- expensive compared to other techniques. can only capture clear image if person stays still. poor temporal resolution as has 5-second lag between task and neural activity
EEG
evaluation
strength- good temporal validity as able to see changes to brain in real time sp accurately able to measure a task or particular activity and the area associated with it. allows conclusions to be made on various brain functions such as sleep patterns
limitation- low spatial validity as electrodes so close together on head and can pick up other signals so unable to show what each part of brain is doing. limits effectiveness for being able to work out localisation of function
records changes in electrical activity of brain using electrodes attached to the scalp
when electrical signals from different electrodes graphed over period of time the resulting representation called EEG
electrodes put on scalp and detect neuronal activity directly below where they are placed
recording represents the brainwave patterns that are generated from the action of millions of neurons
indicates whether brain wave activity is rhythmic or not
ERP
electrodes put on scalp and detect neuronal activity (directly below where placed) in response to stimulus introduced by researcher.
event-related potentials
ERPs are type of brainwave that are triggered by a particular event
researchers generated way of isolating responses from EEG with statistical averaging technique which filters out unnesecary info so researchers can see responses that relate to the presentation of specific stimulus
evaluation
strength- takes continuous set of data so researchers able to determine what is happening in brain in real time and due to different responses
limitation- extraneous signals which may affect results and poor spatial resolution so researchers uable to work out what part of brain active at a certain time and difficult to assess exactly where activity is being represented on screen
ERP and EEG
similarities
both use electrodes placed on head to measure brain activity
both have good temporal validity but poor spatial
both non invasive
differences
EEG recording of general brain activity usually linked to states such as sleep and arousal, whilst ERPs are elicited by specific stimuli presented to the ptpt