Ruth S. Day / Duke University /

Research Basic Cognition Everyday Cognition

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Cogito, ergo sum.

Basic Processes Alternative Representations Knowledge Structures
Linguistic Codability Individual Differences


Cognition involves basic mental processes such as:
--problem solving
--decision making

The Day Cognition Lab studies a wide range of basic cognitive processes and their interconnections, especially memory, comprehension, representation, and problem solving. Major projects are described below.


All information can be represented in alternative formats, such as text, lists, outlines, matrices, tree diagrams, and other spatial arrangements. Each representation carries its own cognitive consequences -- it has characteristic effects on perception, memory, comprehension, problem solving, and other cognitive processes. There is no one "correct" way to represent information. It depends not only on the nature of the information itself, but also on the cognitive task(s) to be performed. For example, a grocery shopper with time constraints will do better with a list ordered by spatial location in the store, while one still thinking about dishes for a given meal may benefit from having a dish-ordered list. The idea of alternative representations of the same information (Day, 1988) holds implications for how experiments in cognitive psychology are conducted and interpreted, as well as for situations in everyday cognition.

Sample Paper
Day, R. S. Alternative representations. In G.H. Bower (Ed.), The Psychology of
  Learning and Motivation. New York: Academic Press, 1988, 22, 261-305.


Many empirical studies about knowledge examine how much people know about various content domains, from physics and history to movies and chess. Our research examines the structure of such knowledge. For example, is the information loosely structured based on weak associations, or is it structured in a systematic, hierarchical way? To study knowledge structures, we use a variety of empirical and quantitative methods (such as hierarchical clustering). Experiments examine:
  --what knowledge structures are
--how to measure them
--how they vary across content domains
--how they vary with degrees of expertise
--how to foster their development

Sample Paper
Day, Ruth S. Knowledge vs. knowledge structures. In W. A Cashin (Ed.),
  National Issues in Higher Education, 1987, 26, 35-56.


Linguistic codability is the ease with which people can name things and the effects of naming on cognition and behavior.

linguistic codability diagram

For example, previous research showed that the ability to name a color helps people remember it later. Our research examines the effect of linguistic codability across sensory modalities including vision, taste, and smell as well as information in everyday cognition contexts such as facial expressions and motor movement. It also examines individual differences in linguistic codability.


Individuals differ in many ways. Many investigators study how individuals differ based on distinctions such as age, gender, "intelligence," and education level. Our research takes a different approach - it studies whether individuals differ in their overall cognitive pattern. Some individuals appear to be "language-based" while others are "language-optional" (Day, 1977). These two groups perform in characteristically different ways on many cognitive tasks including short-term memory, long-term memory, foreign-language skills, and music skills.

We often find "typical" results for classic cognitive experiments, but only when the data are averaged over all individuals. When examined separately, the two groups show very different patterns of performance. This work suggests intriguing implications for the general nature of cognitive theories as well as the nature of individual differences in cognition.

Sample Papers
Day, Ruth S. Systematic individual differences in information processing. In P. G.
  Zimbardo and F. L. Ruch, Psychology and Life. Glenview, IL: Scott, Foresman, 1977. Pp. 5A-5D.

Day, Ruth S. Verbal fluency and the language-bound effect. In C. J. Fillmore, D.
  Kempler, and W. S-Y. Want (Eds.), Individual Differences in Language Ability and Language Behavior. New York: Academic Press, 1979. Pp. 57-84.

Basic Cognition