Psychologically, perception is viewed as the process of organizing and interpreting
sensory information, enabling one to recognize meaningful objects and events. This can basically occur through two different processes: top-down processing and bottom-up processing.
Bottom-up processing is the type that begins with the senses and then is organized into a coherent picture in the brain. Top-down processing, however, is made by having the higher-level processing in the brain interpret information based on expectations and past experiences. This type of processing can result in
misperceptions and
illusions. While this is a drawback of top-down processing, it is much faster than bottom-up processing and is useful in the day-to -day functioning of the person.