Final answer:
The constraint on the amount of information people can handle is their processing capacity, which is linked to cognitive psychology and the limits of information processing.
Step-by-step explanation:
The amount of information people can handle is constrained by their processing capacity. Perception is the process by which we organize, interpret, and consciously experience sensory information, and this relates to both bottom-up and top-down processing. The term processing capacity ties into cognitive psychology and refers to the limit of our cognitive system's ability to engage in processing information.