Conceptual Categorization

Whereas perceptual categories Opens in new window compute object groups based on their appearance; conceptual categories compute class membership based on an object’s role or function in events.

Conceptual categorization, the focus of this entry, involves deliberation, meaning, and interpretation. Development of conceptual categories seems to go from the abstract to the more concrete.

Distinguishing Conceptual Categories from Perceptual Categories

• Whereas perceptual categories Opens in new window operate primarily to segment patterns of energy that immediately impinge on our senses, conceptual categories operate to identify and generalize (relate through long-term memory) the perceptual units established by perceptual categorization.
• Conceptual categorization operates on information within the brain (memory) in relation to its sensory input. Unlike perceptual categorization, conceptual categorization can be the result of a conscious act.
• Where perceptual categorization deals with single objects or events, conceptual categorization links together memories of objects and events that have occurred at different times (Edelman, 1989).

The connections between the components of a conceptual category, rather than being established on the basis of simultaneity or spatial contiguity, as in much perceptual categorization Opens in new window, are established in relation to an organism’s memory and values.

Conceptual categories can thus be idiosyncratic—they can vary, depending on individual history. Conceptual categories always involve the past.

Note that conceptual categories are not necessarily equivalent to or dependent on, language. They can exist prior to language Opens in new window, although many conceptual categories may be related to words in a language.

Conceptual categorization groups the separate objects or events of perceptual categorization Opens in new window into higher-level categories, which consist of abstractions of memories of many objects or events that are somehow related. The process often called “identification” is essentially “re-cognition” of category membership.

Conceptual categories are memory-driven ways of dividing up experience. As part of the structure of long-term semantic memory Opens in new window, they help form the context for experience.

The ability to conceptually categorize an area of experience can enhance memory. The activation of conceptual categories in long-term memory Opens in new window can help to encode experience in rememberable units.

Learning to recognize types of objects and events, such as cars, birds, or pitch intervals (as opposed to merely discriminating their individual presence, as in perceptual categorization) is a primary aspect of conceptual categorization, although it is probably the case that not all conceptual categories are established just on the basis of experience (Hirschfeld and Gelman, 1994).

Whereas conceptual categories may become connected to words in a language, many concepts themselves are prelinguistic. They are a kind of generalized perceptual abstraction. That they are largely learned and assume a variety of structures are defining characteristics of conceptual categories.

Common to many conceptual categories is a graded structure, in which some items are considered “better” or more representative members—more “prototypical”—of a category than others.

• In the category of bird, for example, a robin is considered more prototypical than a pelican (within the European culture, at least).
• In the category of musical interval, an interval of a perfect fifth perfectly in tune could be considered (by a trained listener) more prototypical than an interval on the border between a perfect fifth and a minor sixth.

Due to the phenomenon of chunking Opens in new window, many conceptual categories are arranged in multileveled memory structures called “hierarchies,” whose different levels often correspond to different amounts of detail and abstraction.

There is usually a particular level of detail at the “middle” of the hierarchy that is the most accessible and the most frequently used. Called the basic level of categorization, it serves as the entry level to the hierarchy.

It is the level at which we most easily categorize the world, indeed, the level at which our conceptual grasp of the world is grounded (Lakoff, 1987).

Midway between the highly abstract and the extremely detailed, it is also often the first level at which children learn words for things.

Thus in music, a basic level categorical unit would be a phrase, rather than a note or a section (Zbikowski, 1991), the level at which we most easily immediately grasp (chunk) musical structure.

Another aspect of basic level categories is that they are the result of our physical interactions with the world. A musical phrase, for example, often represents one coherent physical gesture, such as a single breath, or a single movement of a bow.

Because the physical capacities of human beings (as well as the capacity of short-term memory) are similar in many different places and times, the phrase level of grouping is found in many different kinds of music.

Certainly perceptual and conceptual categories interact in many ways. Most conceptual categories must be built up from perceptual categories Opens in new window.

Because they involve individual long-term memory Opens in new window, however, the higher-level conceptual categories can have a much more idiosyncratic structure. Conceptual categories are represented differently in different individuals, and even in a single individual, depending on how they are used (Barsalou, 1993).