In comparison to sensation, perception is a much broader concept. Sensation involves simply receiving stimuli through sensory organs, whereas the process of perception involves receiving raw data from the senses and then filtering, modifying or transforming the data completely through the process of cognition. The processes of perception consist of various subprocesses such as confrontation, registration, interpretation and feedback.
Though people are continuously exposed to numerous stimuli, they tend to select only a few of them. The principle of perceptual selectivity seeks to explain how, and why people select only a few stimuli out of the many stimuli they keep encountering at any given time. Perceptual selectivity is affected by various internal set factors and external attention factors. Some of the internal set factors are learning, motivation and personality. External attention factors include environmental influences like intensity, size, contrast, repetition, motion, novelty and familiarity.
Sometimes, different individuals may perceive the same thing differently. Differences may arise due to factors associated with the perceiver (attitudes, motives, expectations, etc.) or the situation (time, place, etc.) or the target (novelty, background, sounds, size, etc.).
Perceptual organization focuses on the subsequent activities in the perceptual process after the information from the situation is received.
The various principles of perceptual organization consist of figure-ground, perceptual grouping, perceptual constancy, perceptual context and perceptual defense. The principle of figure-ground states that