What is brain mapping and how is it done
       Brain mapping is a technique that aims to relate the brain’s structure to its function by a process of stimulating different areas of the brain and monitoring any change in behaviour. It makes use of various brain mapping techniques such as electro encephalography (EEG), magneto encephalography (MEG), positron emission tomography (PET), magnetic resonance imaging (MRI) etc for the study of the anatomy and function of the brain and spinal. This process aims to relate various parts of a brain to its associated function or to find what parts of the brain controls what part of the body. For example some parts of the brain controls vision while some other part controls hearing ability and brain mapping helps identify these parts.
      A number of brain mapping methods are available today and depending on the type of brain mapping method, they employ different techniques for the process. One of the popular techniques used to study the structure of the brain is called computerized tomography(CT) scan. It is an x-ray procedure that combines many x-ray images with the help of computer to produce section and three dimensional views of internal organs including the brain. Several x-ray images are taken with the help of a doughnut shaped CT scanner at various angles. All these images are processed by a computer and hence 3 dimensional and cross sectional images of the body can be created.
      Brain mapping is extensively used in diagnosing and treating with high precision various neurological disorders such as tumours, epilepsy, Alzheimer’s disease, Parkinson’s disease etc. It is also used in the treatment of psychiatric disorders such as depression, schizophrenia etc. It is used during surgery to identify important parts of the brain. Parts of the brain associated with various functions of the body such as vision and smell can be identified and thus removal of these essential parts can be avoided. This  is usually done by passing a small current through the exposed part of the brain and observing the response of the patient who is awake.

References


[1] http://en.wikipedia.org/wiki/Brain_mapping
[2] http://www.mayoclinic.org/awake-brain-surgery/
[3] http://www.hindu.com/seta/2006/05/04/stories/2006050400191600.htm
[4] http://www.medicinenet.com/cat_scan/article.htm
[5] http://science.howstuffworks.com/life/inside-the-mind/human-brain/brain-mapping.htm
[6] http://en.wikipedia.org/wiki/Brain_mapping