ways of studying the brain Flashcards
what is an fmri
measures oxygenated blood flow in the brain i.e. brain activity when someone is performing a task
does this have good or bad spatial resolution
good (1mm)
good or bad temporal res
bad (5 second delay)
what is an EEG
sensors on scalp which gives us brain waves- changes in electrical activity in the brain. Detailed information and a comprehensive picture of the brain can be derived
good or bad spatial
bad (struggle to pinpoint exact location of brain activity)
good or bad temporal
good- milli second precision- can track rapid changes in neural activity.
what is an ERP
EEG done over time and something. E.g cause pain and see change in brain wave activity.
good or bad spatial
bad (difficult to precisely localize the source of the activity in the brain)
good or bad temporal
good (milli second scale)
what is post mortem
studying/ examining someone’s brain after they died- autopsy
good or bad spatial
good (allow for microscopic and even molecular-level examination)
good or bad temporal
bad (do not provide real time information about brain activity)
advantage of fmri
non-invasive procedure which means that participants are protected from injections of potentially harmful substances (PET scans involve injection of a radioactive tracer into the participant)
This means that fMRI has good ethical validity
whats a disadvantage
Expensive and not widely available- smaller sample sizes
More ideographic research- harder to establish reliable conclusions.
Harder to generalise findings
Difficult for researchers to conduct repeated scans over time, limiting the ability to track changes in brain activity longitudinally.
advantage of EEG (case to back it)
historically important in understanding sleep patterns e.g.
Dement & Kleitman (1957) used EEG to determine the five different stages of sleep
A key finding was that eye movements were linked to phases of dreaming (this was termed REM = rapid eye movement)
Eye movements reflected the type of dream e.g. a dream about throwing tomatoes at a wall occurred when the participant’s eyes moved side to side
These findings were only possible due to the use of EEG
disadvantage
only detect surface activity within accessible regions of the brain
This is a limitation as EEGs cannot provide insight as to what is happening in deeper regions of the brain (e.g. the amygdala)
advantage of ERP
ERPs are much cheaper than the more costly fMRI scanning
This is a strength as it means that they are likely to be utilized much more readily and widely than other more expensive techniques
Therefore conditions such as epilepsy may be easier to diagnose
disadvantage
An ERP signal cannot pinpoint with 100% accuracy the exact source of specific brain activity
More than one electrode may pick up the activity’s signal
This can lead to confusion as to what the signal is and from which part of the brain it originates
advantage of post mortem
Direct study of brain anatomy and bio-chemistry. Contributed to understanding of brain structure and chemical makeup of the brain. Unlike fMRI/MRI which can only provide images of the brain.
disadvantage
It is difficult to compare post-mortem slices of a brain after death with actual brain functioning before death
This means that PME lacks ecological validity as the ‘real’, living brain of the person when alive is not reflected in the use of this technique
