We often come across pictures where our mind perceives the image as something else. Based on our own expectations, we perceive those images differently. That is due to parallel processing; the ability of the brain to attend to many sense modalities simultaneously of differing qualities. There are two concepts that follow along with parallel processing. The bottom-up processing is when a whole image is constructed from parts of the picture. For example based on a person's own expectation of the picture shown below, they would see the image of a man's face. The tunnel part makes up the eye on the left and the branch sticking out from the tree makes up the other eye. Along with the eyes, the woman in the field makes up the nose and mouth. Here, our brain's expectations perceived the image of a man's face. On the other hand, with our second concept, the top-down process, the brain's function would allow the person to see the image of the woman in the field. Both of these processes are due to our own expectations or knowledge which influences our perception of pictures that we see.