There are several methods for studying the human brain. Some methods are observational, while others are invasive. Some would argue that the invasive methods are unethical and this research should only involve animals other than humans, however, there are occasions where invasive methods of investigating the human brain become necessary.When stereotaxic surgery is being performed, a two dimensional atlas is used to access the specific area requiring treatment. The patient's head is firmly held in position necessary for surgery, and a device called an electrode holder is positioned to make the





