Alyson looks at a picture of arrows and sees white arrows pointing to the right against a black background. She looks at the picture longer, and then sees black arrows pointing to the left against a white background. Her perception of the stimulus is an example ofAlyson looks at a picture of arrows and sees white arrows pointing to the right against a black background. She looks at the picture longer, and then sees black arrows pointing to the left against a white background. Her perception of the stimulus is an example of:___________