Bottom-up Processing
Bottom-up processing builds perception from raw sensory input upward.
Why start from the signal?
Without grounding in the actual signal, perception would just be hallucination from priors.
Three classic models of how vision does this:
- Template matching: match input to a stored pattern
- Feature analysis: identify component features of a stimulus
- Prototype model: compare input to an idealized best-fit representation
Most perception is a mix of bottom-up and top-down.