Advertisers, of course, know that their pitch will be more effective if it gets your attention. Ads are therefore loud, repetitious, and intentionally irritating. In addition to directing attention, motives may alter what is perceived. And, an emotional stimulus can shift attention away from other information. D. Perceptual Expectancies .
Perception seems to proceed in two major ways.
The reverse also seems to occur. Many experinces are organized using one's knowledge of the world. This is called top-down processing . In this case, pre-existing knowledge is used to rapidly organize features into a meaningful whole. Another good example of top-down processing is found in perceptual expectancies.