After skipping lunch to finish a project, Sarah is walking home and finds herself noticing every restaurant, bakery, and food advertisement she passes, things she normally wouldn't pay attention to. Which psychological principle best explains Sarah's heightened awareness of food-related cues?

After skipping lunch to finish a project, Alex is walking through a crowded food court. Alex is convinced they smell pizza baking nearby, even though their friend, who just ate, cannot detect the smell. Which of the following best explains Alex's perceptual experience?