Dynamic Memory: Keeping Track of Continually Changing Information

Abstract

The requirement to remember continuously changing information places substantial demands on the human operator's working memory system. Previous research (Yntema & Mueser, 1960) found that in keeping track of dynamically changing information, humans' memory for changing information was better when they kept track of many different attributes of a single object than when they kept track of the identical attribute of many different objects. Due to a confound in the Yntema and Mueser experiment, the unique and combined effects of information organization and similarity-based interference cannot be determined, limiting the information about dynamic memory. This experiment represents an attempt to overcome this limitation by assessing the roles of organization and similarity-based interference in dynamic memory. The experimental task was a keeping track task in which a series of changing attribute values were presented sequentially, and subjects were required to remember the most recent update for each attribute. Three factors were manipulated in the experiment: number of “objects” (one vs many objects), type of attribute (same vs different), and memory load (2, 4, or 6 attributes to remember). Results showed that as memory load increased, keeping track performance in the many-object condition decreased to a greater extent than in the one-object condition. Also, as memory load increased, accuracy decreased at a greater rate for the same-attribute condition than for the different-attribute condition. The effect size for attribute similarity was much larger than that for number of objects. It was concluded that similarity-based interference is quite destructive to dynamic memory. It appears that the cost of attribute similarity far outweighs the benefits of organizing the continually-changing attributes. Such results have implications for structuring tasks and aiding memory in situations where operators must remember information in dynamically changing environments.