Method
Description
Case
Studies
Direct
An electrode is
Electrode
used to effect areas
Stimulation of the brain
Single
Pulse TMS
Key Feature
How the
technique is used
Research example
Advantages
Limitations
Needs an
exposed brain
and the patient
to be conscious.
Uses a device that
emits a weak
electrical current
to activate or
disrupt the
normal activity of
neurons.
Delivers a
magnetic field
pulse through the
skull.
Wilder Penfield
(1891-1976) used the
technique to locate
and map functions of
areas of the brain.
Effective for
research. Is reliable
Extremely invasive
Stimulated the area of
the cortex responsible
for thumb movement
Fired at Broca’s area
and induced aphasia
in order to study it.
Can help pinpoint
specific areas of
cortical brain
damage. Can
ethically produce
temporary brain
damage symptoms
for research.
Electrodes are
attached to a
patients scalp and
produce
measurement of
electrical activity
Patient is injected
with a contrast,
placed in the
scanner and then
x-rayed from
many different
angles
Computer
processes images
received by
Used to study people
with apraxia – showed
that non-primary
motor cortex areas
have a role in
initiating movement.
Used to look for and
identify possible
abnormalities in brain
structures
Useful for providing
general, overall
information about
brain activity.
Can’t be used on
patients with metal in
them or who have a
history of seizures.
Can cause headaches
and seizures in a few
participants. Can only
be used to affect the top
part of the cortex.
Does not provide
detailed information
about which areas of
the brain are activated.
Identifying the
precise location of
damage or
abnormalities.
Shows change over
time.
Does not provide
information about the
activity of the brain.
Used to diagnose
unusual disorders and
the area of the brain
Very sensitive, can
identify cancer,
blood clots and other
Can’t be used on people
with metal in them, and
does not give
The pulse activates
the neurons in that
area of the brain.
Repeated pulses
stop neurons firing.
Does not require
surgical
procedure.
Fires repeated,
but not
necessarily rapid
pulses.
EEG
Used to measure
and record
brainwave activity
Able to identify
distinctive
patterns of
electrical activity
CT
Produces a
computer
enhanced image of
slices of the brain
Enables effective
detection of
brain changes
over time
MRI
Uses harmless
magnetic fields and
radio waves to
Primarily used
to diagnose
structural
rTMS
vibrate atoms in
the brain’s neurons
to produce an
image.
Description
abnormalities
PET
Uses a radioactive
tracer to enable
production of a
computer
generated image
Tracks blood
flow around the
brain. More
activity = more
blood flow.
SPECT
A variation of PET
and uses a single
photon and a
longer lasting
radioactive tracer.
fMRI
The computer
analyses the blood
oxygen levels in an
area and creates an
image with colour
variations.
Method
used.
extremely small
changes in the brain.
information about
function
Research example
Advantages
Limitations
Widely used in
research on which
areas of the brain are
active when certain
tasks are being
performed or
thoughts are taking
place etc.
Enables detailed
images of the brain
at work. Can
observe how
different areas of the
brain interact. Can
use normal brain
people in research.
Can be merged
Same as for PET
with CT scans to
enable more
accurate location
of an area.
Comparing a healthy
brain with that of an
Alzheimer patient.
Based on an MRI
and detects
changes in
oxygen levels in
the blood in the
brain.
Scans showing areas
of the brain activated
when thinking about
certain things. Has
demonstrated that the
right hemisphere
plays a larger part in
verbal tasks than
previously believed.
Can be used to track
much longer tasks
than PET and is
considerably
cheaper to use than
PET
Images are more
detailed than PET or
SPECT. Can provide
quick changes in
brain activity.
Cannot determine
whether an active brain
area is actually involved
in the task being
studied.. Can only be
used to study short
tasks. Does not pick up
rapid changes in the
brain.
Images not as good as
PET
Key Feature
magnet and
assembles them
into a coloured
image.
How the
technique is used
Records levels of
activity in
different areas of
the brain while
doing a specific
task
Used more for
research into
brain function
than diagnosis.
Cannot determine
cause-affect
relationships between
brain activity and task
being pbserved.