The Active Nature of Perception
Perception refers to the higher processing of sensation that eventually becomes how people experience the world around them (Geisler, 2008). People tend to either consciously or selectively perceive some aspects of the world more than others. A perfect example is when a person chooses to concentrate on what he/she is typing on the computer currently as opposed to the feeling of the keyboard buttons that the individual is pressing. In most cases, the former is highly relevant to the task the person is doing compared to the latter. Though some of these processes seem to be automatic, they are active. In such a scenario, we can say that perception is variable and active (Toivanen, 2013).
Differences between Bottom-Up and Top-Down Perception
Bottom-up and top-down perception are the two general processes involved in sensation and perception (Proulx, 2007). Bottom-up perception is the processing of sensory information as it is coming through the five senses. Therefore, if a person flashes a random image on the screen, the eyes detect the features, the brain puts the pieces together and the person perceives the picture of an animal, let us say a cat. What the individual sees on the screen is solely based on the sensory information coming in mind. Bottom-up can be defined as the way something is built up by using the smallest particles of sensory information (Proulx, 2007).
In contrast, top-down refers to the process whereby knowledge is used to guide the perception (Geisler, 2008). While the bottom-up process begins with small pieces of information and builds them together to form the bigger picture, the top-down process begins with the big picture and then breaks it down into smaller pieces of information.
As a student, I often apply the bottom-up theory in my studies. Therefore, when my bottom-up perception was impaired, my everyday learning experience was affected. This normally occurs when I cannot understand some images that I come across in the class textbooks. The bottom-up perception enables me to see these pictures and then my mind collects small pieces of information, which allow me to describe the pictures.
Geisler, W. S. (2008). Visual perception and the statistical properties of natural scenes. Annual Review of Psychology, 59, 167–192.
Proulx, M. J. (2007). Bottom-up guidance in visual search for conjunctions. Journal of Experimental Psychology: Human Perception and Performance, 33(1), 48–56.
Toivanen, J. (2013). Perception and the internal senses: Peter of John Olivi on the cognitive functions of the sensitive soul. Leiden: Brill