Source: Laboratory of Jonathan Flombaum—Johns Hopkins University

Human memory is limited. Throughout most of its history, experimental psychology has focused on investigating the discrete, quantitative limits of memory—how many individual pieces of information a person can remember. Recently, experimental psychologists have also become interested in more qualitative limits—how precisely is information stored?

The concept of memory precision can be both intuitive and elusive at once. It is intuitive, for example, to think a person can remember precisely how their mother sounds, making it possible to recognize one’s mother immediately over the phone or in a crowd. But how can one quantify the precision of such a memory? Exactly how similar is the memory to the voice itself?

To study the precision of memory and working memory, in particular, experimental psychologists have devised a paradigm known as delayed estimation. It has been used most often, thus far, to study the precision of visual memories, especially memory for color, and to understand how memory degrades the more one tries to remember at once. This video demonstrates standard procedures for investigating the precision of color working memory using delayed estimation, with a focus on how memory is affected as one tries to remember the colors of more objects simultaneously.