How I organize what I see. Factors inherent to the stimuli force themselves upon us. Motivation, prior learning and personality can enhance or dull our perceptions. We learn to receive some messages and to block out others. Sex, money, ethnic identity.
Perceptual organization is what the mind does with information once it is received.
Figure - ground. We choose our figures. Fill in gaps. Complete an object so perceived as a whole. Forest v. trees.