Cognition

A general term for the higher mental processes by which people acquire knowledge, solve problems, and plan for the future.

Cognition depends on the ability to imagine or represent objects and events that are not physically present at a given moment. Cognitive functions include attention, perception, thinking, judging, decision making, problem solving, memory, and linguistic ability.

One of the most basic cognitive functions is the ability to conceptualize, or group individual items together as instances of a single concept or category, such as "apple" or "chair." Concepts provide the fundamental framework for thought, allowing people to relate most objects and events they encounter to preexisting categories. People learn concepts by building prototypes to which variations are added and by forming and testing hypotheses about which items belong to a particular category. Most thinking combines concepts in different forms. Examples of different forms concepts take include propositions (proposals or possibilities), mental models (visualizing the physical form an idea might take), schemas (diagrams or maps), scripts (scenarios), and images (physical models of the item). Other fundamental aspects of cognition are reasoning, the process by which people formulate arguments and arrive at conclusions, and problem solving—devising a useful representation of a problem and planning, executing, and evaluating a solution.

Memory—another cognitive function—is crucial to learning, communication, and even to one's sense of identity (as evidenced by the effects of amnesia). Short-term memory provides the basis for one's working model of the world and makes possible most other mental functions; long-term memory stores information for longer periods of time. The three basic processes common to both short- and long-term memory are encoding, which deposits information in the memory; storage; and retrieval. Currently, the question of whether short- and long-term memory are qualitatively and biologically distinct is a matter of debate.

The cognitive function that most distinctively sets humans apart from other animals is the ability to communicate through language, which involves expressing propositions as sentences and understanding such expressions when we hear or read them. Language also enables the mind to communicate with itself. The interaction between language and thought has been a topic of much speculation. Of historical interest is the work of Benjamin Whorf (1897-1941), the proponent of the idea that the language people use determines the way in which they view the world. As of the late 1990s, most psychologists view the Whorfian hypothesis with skepticism, believing that language and perception interact to influence one another.

Language acquisition is another topic of debate, with some—including psycholinguist Noam Chomsky —arguing that all humans have innate language abilities, while behaviorists stress the role of conditioning and social learning theorists stress the importance of imitation and reinforcement.

Since the 1950s, cognitive psychology, which focuses on the relationship between cognitive processes and behavior, has occupied a central place in psychological research. The cognitive psychologist studies human perceptions and the ways in which cognitive processes operate on them to produce responses. One of the foremost cognitive psychologists is Jerome Bruner, who has done important work on the ways in which needs, motivations, and expectations (or "mental sets") affect perception. In 1960, Bruner and his colleague, George A. Miller, established the Harvard Center for Cognitive Studies, which was influential in the "cognitive revolution" of the following years. In the area of linguistics, the work of Noam Chomsky has rekindled the age-old debate over whether language exists in the mind before experience. Other well-known work in cognitive psychology includes that of D.E. Berlyne on curiosity and information seeking; George Kelly's theory of personal constructs; and investigations by Herman Witkin, Riley Gardner, and George Klein on individual perceptual and cognitive styles.

The development of the modern computer has influenced current ways of thinking about cognition through computer simulation of cognitive processes for research purposes and through the creation of information-processing models. These models portray cognition as a system that receives information, represents it with symbols, and then manipulates the representations in various ways. The senses transmit information from outside stimuli to the brain, which applies perceptual processes to interpret it and then decides how to respond to it. The information may simply be stored in the memory or it may be acted on. Acting on it usually affects a person's environment in some way, providing more feedback for the system to process. Major contributions in the area of information processing include D.E. Broadbent's information theory of attention, learning, and memory; and Miller, Galanter, and Pribram's analysis of planning and problem solving.