differentiation

The process by which perception becomes finer — what was one category becomes several, what was a blur becomes a set of distinct features. Perceptual learning builds differentiation by enlarging cortical representation for the trained dimension and creating more specific detectors (Wikipedia: Perceptual learning, read 2026-06-18).

Differentiation is the perceptual side of expertise: the wine taster who can tell two vintages apart, the drummer who hears the downbeat the novice misses. It is separate from preference — you can differentiate without preferring — but it opens the door to preference by making differences available for liking to attach to.