Final answer:
Bottom-up processing refers to information processing starting with incoming stimuli and moving upwards to the brain, while top-down processing involves the use of previous knowledge and expectations to interpret and guide cognition.
Step-by-step explanation:
Bottom-up and top-down processes are two distinctive approaches to understanding how information is interpreted in the brain. Bottom-up processes involve data-driven cognition, where perception starts with stimuli entering the sensory systems and moves upward to the brain. It is an automatic, fast and reflexive form of information processing that doesn't involve conscious thought.
Conversely, top-down processes are guided by knowledge, experiences, and expectations. An example of a top-down process is looking for misplaced keys with a yellow key fob; you would deliberately search locations where the keys are likely to be based on your prior knowledge and ignore places like the ceiling fan, where keys are not usually found. This type of process is slower, more deliberate, and controlled by conscious thought.
The distinguishing factor between the two is that bottom-up processing is driven purely by the sensory input without the influence of preconceived knowledge, whereas top-down processing is influenced by our beliefs and expectations which guide perception and cognition.