What is the difference between bottom-up and top-down processing?

• A. Bottom-up data-driven from sensory input; top-down guided by expectations and prior knowledge.
• B. Both rely only on memory retrieval.
• C. Bottom-up uses prior knowledge; top-down ignores sensory input.
• D. They are identical.

Answer: (A)

Perception operates through two complementary ways. Bottom-up processing is data-driven, starting with the raw sensory input from the environment and building up to a complete percept. Top-down processing, on the other hand, is guided by your expectations, prior knowledge, and the surrounding context, using what you already know to interpret what you sense. For example, when you look at a blurry image, bottom-up processing relies on the actual visual signals you receive (edges, colors, contrasts) to form a perception, while top-down processing uses your expectations or knowledge to fill in gaps and interpret what you’re seeing. The statement that bottom-up is data-driven from sensory input and top-down is guided by expectations and prior knowledge captures this fundamental contrast. The other options don’t fit: memory retrieval alone doesn’t account for how sensory data is processed in bottom-up processing, top-down processing does not ignore sensory input, and the two processes are not identical.