Richard Roberts

Top-down processes, which are also referred to as conceptually driven processes, utilize what you already know in service of perception and comprehension.

the cognitive system is able to fill in the missing information, even without you being aware that this is happening.

Bottom-up processing, which is also referred to as data-driven processing, is the opposite of top-down processing. This term refers to situations in which you perceive a stimulus without preconceptions or assumptions about what you’re experiencing.