split-brain research is a fairly recent area of study. It began with discoveries made while observing patient who had lost either left-side or right-side brain function . for example , it was noted that left-hemisphere damage adversely affected speech and language competence. this led to the conclusion that these skills are located in the left side of the brain . Such discoveries have supplied a foundation for further study. Advances in research tools and techniques are allowing scientists to pinpoint which parts of the brain are responsible for certain activities and responses. by recording brain waves and monitoring blood flow in each hemisphere of the brain ,researchers can correlate there aspects of brain activity with various kinds of mental performance . There observation have enhanced our understanding of the complexities of human intelligence.