Lateralization is a process of studying the split functions of the brain hemispheres. The most common test used for testing lateralization is obtained from sodium amytal studies. In this study a barbiturate or a sedative is injected into the carotid artery either left or the right artery. So, till the time the barbiturate hampers the functioning of any hemisphere, the functions associated with that hemisphere also gets hampered or are sustained for a while. This technique is of invasive nature
