What region is it? The region where all this stuff is emanating from, that is. That would be the limbic system of the brain, which the sense of smell is directly linked with, and the emotional center of the brain. Thus, inhaling Essential Oils directly affects your mood. No hocus pocus, just brain structure. This is why women often put on perfume when they need a little “lift” in their spirits. This is why Disneyland has the smell of vanilla wafting thru Main Street to make the Happiest Place on Earth a little more happier. This is why savvy bed & breakfast places have either bread or cookies in the oven when guests arrive.