A technique that takes raw EEG data and uses it to investigate cognitive processes of a specific
event. It achieves this by taking multiple regions and averaging them in order to filter out
unrelated brain activity.
STRENGTHS
It is possible to determine how
processing is affected by a specific
experimental manipulation, e.g. during
presentation of different stimuli.
Can measure the processing of stimuli even
in the absence of a behavioural response. The
processing can be covertly measured without
the person responding to the stimuli.
LIMITATIONS
ERPs are small and difficult to pick out from other
electrical activity in the brain, so it requires a a
large number of trials to gain meaningful data.
Only sufficiently strong voltage changes
generated across the scalp are recordable
- restricted to the neocortex.
Functional Magnetic Resonance Imaging (fMRI)
A technique used for measuring brain activity. It works by detecting changes in blood
oxygenation and flow that indicate increased neural activity in a particular region of the brain.
STRENGTHS
Non-invasive - it does not
expose the brain to
potentially harmful
radiation.
Offers a more objective and reliable
measure of psychological processes
than verbal reports.
LIMITATIONS
Indirect measure of neural activity - it only
measures the changes in blood flow in the
brain not the actual activity.
Overlooks the networked nature
of brain activity, as it focuses
only on localised activity.
Electroencephalogram (EEG)
A method of recording
changes in the electrical
activity of the brain using
electrodes attached to the
scalp.
STRENGTHS
Provides a recording of the brain in real time. This
allows the researcher to accurately measure a
particular task or activity with the brain activity
associated with it.
Useful in clinical diagnosis - we can
determine if someone having seizures is
suffering from epilepsy by recording
abnormal neural activity associated with
epilepsy.
WEAKNESSES
Cannot reveal what is going on in the deeper
regions of the brain such as the hypothalamus or
the hippocampus, as it is unethical to implant
electrodes into a human brain.
The EEG signal is not useful for pinpointing activity in the
brain because electrical signal can be picked up by nearby
electrodes. It doesnt allow researchers
Post Mortem Examinations
Ways of examining the brains
of people who have shown
psychological abnormalities
prior to their death in an
attempt to establish the
possible neuarbiological
cause for this behaviour.
STRENGTHS
Allow for a more detailed examination of anatomical
and neurochemical aspects of the brain that wouldnt be
possible using scanning techniques. Researchers can
examine deeper regions of the brain.
Harrison (2000) - Researchers have been able to
find evidence of changes in neurotransmitter
systems and structural abnormalities of the
brain associated with schizophrenia.
WEAKNESSES
Retrospective approach - limited because the
researcher is unable to follow up on anything that
arises from the post-mortem concerning a possible
relationship between brain abnormalities and cognitive
functioning.
Individual differences due to cause of death, age,
progression of illness etc are all confounding
variables to post-mortem research.