Categorization

Chapter 5 endnote 14, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

You have experienced a diverse population of instances of the concept “Sadness,” which reside in bits and pieces in your head, and in the blink of an eye, your brain constructs a summary of sadness that best fits the situation. [...] Your brain is using something like pattern classification.

In the statistical version of pattern classification, new instances are assigned to a category based on their similarity to some statistical summary. You can think of your brain as performing a similar sort of pattern classification. Where your brain is concerned, sensory input is “assigned to a category” because the input provides the best match to an "on the spot" concept. For example, based on the situation as it is right now, your brain might construct momentary concepts for sadness, anger, and fear to ready your next actions and explain the incoming sensory. The input is specific to situation in time and space. When it arrives to the brain, it helps to select one conceptual representation by either confirming or modifying it. The cognitive psychologist Michael Posner proposed an early version of this idea.