by Yudha Aditya

Created on: February 28, 2010   Last Updated: October 27, 2010

How can we study human mental and psychology phenomena? For researchers, knowing the human brain activity is essential, since the brain works as the major control of mankind. Brain imaging or brain scanning, widely known as the “brain scan”, is a product of modern technology useful for studying more about the brain and its activity; and also detecting abnormalities that may exist in the brain.

There are several kinds of brain scans. People perhaps only know a few of them, for example EEG (Electroencephalography) and CAT (CT) scan, which are quite popular. Actually there are more, like PET (Positron Emission Tomography), MRI (Magnetic Resonance Imaging), and MEG (Magnetoencephalography). Here is a brief explanation about brain scans and how they work.

EEG (Electroencephalography)

EEG or Electroencephalography is a process of recording brain activity by measuring the electrical activity of the brain. The result can be used to know whether there are problems or not.

EEG uses several disks of electrodes, between 16 and 25 disks with different positions on the scalp. The electrodes will pick up the electrical signal produced by each brain cell. Sticky paste is used to prevent the air gap between the disks and the scalp, so the electrical signal can be transmitted easily from skin to the disks without air resistance.

The received signal will be transmitted by wires from each electrode to an amplifier. Since the electrical signal from the brain is pretty weak, the usage of an amplifier is quite important to amplify the signal so it can be read on the next destination, the recording machine. The recording machine converts amplified electrical signals into patterns that can show up on the computer monitor or be saved in a computer disk. Before the computer, a galvanometer hooked with a pen was  used to trace the signal onto graph paper. Since the galvanometer can detect small electrical signals, the process doesn't need an amplifier. The result of EEG, whether it is patterns on screen or traces on paper, can give information about brain activity. Different states or conditions of people in tests, may lead to different pattern characteristics – therefore, it can be used to detect abnormalities by comparing the result with the patterns from a normal condition.

PET (Positron Emission Tomography)

By using radioactive glucose, PET can be used to observe blood flow and metabolism of tissues and organs inside the body, including the

• 1
• 2
• 3
• Next Page >>