How does
the brain work? The brain controls your body by sending out signals through the
nerve-system. It controls a lot of things at the same time like; body
temperature, blood pressure and heart rate. The brain collect, process and
stores information about what is going around you, it collects the info through
seeing, hearing, smelling, touching and tasting. The brain handless physical
movement such as walking, talking and standing. It also allows you to think,
dream and express emotions. If you get Alzheimer’s disease all of these tasks
that the brain does on a daily basis get’s hard for the brain to conduct. The
Alzheimer’s disease makes it harder for the brain to access memories and
perform tasks. The disease does not have a cure, and we do not know what the
cause of Alzheimer’s is but it is possible to spot the disease through brain
imaging technology.
fMRI
The fMRI
(functional Magnetic Resonance Imaging) takes advantage of the fact that when
neurons are active more blood is sent to that area. The fMRI can detect metabolic
changes which indicate brain activity. The fMRI computer creates images, which
are put together to a video. The strengths of fMRI is that it can create a map
of the brain that shows brain activity in real time, it’s easy to use and that
is why it’s often used to detect symptoms of Alzheimer’s disease. The weakness
with fMRI is that the machine is very expensive to buy and operate, and for the
fMRI to work properly the subject must lie completely still. The fMRI can be
used to detect symptoms of Alzheimer’s disease before the patient suffers from
severe memory loss and problems performing tasks. Therefore fMRI can contribute
to detect Alzheimer’s so the disease can be slowed down as soon as possible. The
fMRI is used to localize brain activity and functions of the brain by comparing
damage on the brain and what cognitive functions are malfunctioning.
The fMRI is not only used as a tool to spot and detect
Alzheimer’s, in the case study of “The effects of meditation on the brain” where people with different
skill level in meditation tried to concentrate while being interrupted, showed
us that the fMRI is a excellent tool to see what part of the brain does what in
real time. In the case study we learned that the experienced test subjects had
less brain activity while concentrating.
PET
 |
| PET scan |
The PET
scan (Positron Emission Tomography scan), works by injecting a radioactive
substance into the patient brain. The brain metabolize the substance at different
rates whether the different parts of the brain is active. The gamma rays that
are produced is detected and turned into an image. PET scans are good for
showing a dynamic image. PET scans can be used to spot Alzheimer’s disease, and
that means that it also can contribute to locate Alzheimer’s disease so the
patients can get medicines to slow it down. The weakness with PET scans is that
it is not as precise as fMRI, and the fact that you actually injected
radioactive substance into the patient. PET scans can also evaluate cancer and
blood flow.
As the fMRI the PET scan can be used too many
different tasks, it was used during a study called “PET evaluation of bilingual language
compensation following early childhood brain damage” where the brain of a kid
that was raised by deaf parents and had a brain damage was studied. With the
help of the PET scan, scientists were able to compare the boy’s brain to
healthy average kids. The scan revealed the areas of the brain that were
undeveloped and where the brain damage were located, and the area that was
underdeveloped was the area of the brain where language is “stored”.
