Seize the dynamic images and eye movements
The DIEM project (Dynamic Images and Eye Movements) is an interesting research concept that visually displays where audience members focus their attention when watching videos. Led by Edinburgh University professor John Henderson, they can display the results using a system called CARPE (Computational and Algorithmic Representation and Processing of Eye-movements) that even allows you to put it on your own computer.
This first video shows what part of the people's faces we look at the most. The second one shows a monkey in action, where despite its antics, we always try to follow the face. More videos here.