Cognition, Intelligence, and Causes of Cognitive Impairment

Introduction: What Is Cognition?

Ever since Binet and Simon developed the first intelligence test in 1905, the field of psychology has maintained a strong interest in the nature of intelligence. How do we think? Why are some people better problem solvers than others? What is cognition — the ability to think about our environment? Why are some people consistently more able to use their brains to think, remember, and problem-solve than others?

The first IQ tests were devised to determine which children were intellectually disabled. These children were separated from mainstream education. However, the tests proved effective at predicting school success for all students, and their use was subsequently broadened (Sternberg, 1999). Multiple tests were developed to measure cognition, which might be defined as the ability to think abstractly. Markman (2001) described it in this way:

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.'

The ability to reason about things that are not in our immediate vicinity, or that are abstract concepts, allows us to think beyond the concrete limitations of our environment. Markman lists some of these kinds of abstract thinking as "deductive reasoning, induction, mental simulation, and analogy" (Markman, 2001). Much research has been done on the nature of cognition and on why some people are consistently much stronger or much weaker in their ability to think, remember, and reason — often measured as an IQ score.

This paper examines what cognition is and identifies some of the causes of significant cognitive impairment, a condition in which an individual has a markedly diminished ability to learn and to retrieve information compared to most people. However, Sternberg (1999) makes the important point that, since we are only beginning to explore how the brain works, any tests devised so far are necessarily incomplete measures of the wide variety of ways in which people can think.

Complicating the exploration of cognition is the fact that the brain uses multiple functions to process information. For instance, memory is more than one thing. Immediate short-term memory — sometimes called "active working memory" — allows us to hold information in mind while it is present, such as a phone number we need only long enough to dial. We may then forget it immediately, deliberately commit it to long-term memory, or find it stored permanently simply because it has been repeated enough times. The ability to recall information is crucial to our ability to compare new information to old, to categorize, to develop new knowledge, and even to maintain a sense of self.

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