Vase/Face exercise

This exercise was to help me feel my brain switch from thinking on the left side to the right side. I had to draw a face on the left side of the page while naming all the parts of the face as I drew. As I drew I said outloud "forehead, brow, eyes, top of nose, bottom of nose" and so on. After I was done the first face, I had to draw the same face on the right side, but looking at the other face. This creates an illusion, in my design class they called it gestalt, and if done correctly the image changes from a vase to two faces. The effect that it had on me while I drew, was that when I got to the forehead my pencil stopped and I had a strange conflict in my brain. I then continued to draw the face while not naming the parts any longer and my pencil didn't move as fluid as the first face I drew. The best way to describe how I felt was that my drawing didn't feel natural and I was trying harder. The version below is my 7th try. I added the black circle in Photoshop for clarity.