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Psych professor puts general knowledge to the test

New research by Professor of Psychology Matthew Kelley, along with Ian Neath and Aimée Surprenant from the Memorial University of Newfoundland, was just published in the prestigious Journal of Experimental Psychology: Learning, Memory, & Cognition.

When people are asked to remember a list of words, they tend to remember the first few items (primacy effect) and the last few items (recency effect) well, but are poor at remembering middle items—this pattern of performance is known as a serial position function.  Serial position functions are ubiquitous in episodic memory tasks lasting from milliseconds to seconds, minutes to hours, days to years. 

Serial position functions also have been observed in a few semantic memory tasks, such as when people remember the order of political figures (i.e., the first and last few presidents are recalled better than the middle presidents, with the exception of Abraham Lincoln). Prior research from the Kelley lab also showed serial position functions when people recalled the order of song lyrics, movie releases, and books in a series.

These findings suggest that a general principle of memory  might operate over the short- and long-term, as well as across memory systems (episodic memory, semantic memory).  The “relative distinctiveness principle” can be characterized by a pair of equations and can account for human memory performance in a wide variety of tasks. 

The principle states that: If a set of items can be reasonably ordered along a given dimension, the first and last few items will be more distinct than middle items simply by virtue of the fact that they have fewer neighbors on one side. In contrast, an otherwise comparable set of items that cannot be reasonably ordered should show no such primacy and recency effects. For example, there is no obvious way of ordering the names of the seven dwarves, and there is correspondingly no serial position function observed when they are recalled.  But there are a number of ways of sensibly ordering many stimuli.

In the present study, people ordered exemplars from various categories along a specified dimension—specifically, actors by age, animals by weight, basketball players by height, countries by area, and planets by diameter. In all cases, serial position functions were observed in this general knowledge task and the data were consistent with the predictions of the relative distinctiveness principle. 

In addition to the November publication of their article, Kelley, Neath, and Surprenant will present their work later this week at the Annual Meeting of the Psychonomic Society—the premier cognition conference—which happens to be in Chicago this year.