Recalling items from a category for 1 hour: an inquiry into power-law behavior and memory foraging

There are two complementary approaches to characterizing performance in a free recall task (retrieving items from a specified category). The historic, or top down approach, considers the overall structure of the produced responses, generally as the parameters of a fitted cumulative recall curve. Alternatively, free recall can be considered as a time series of recalls or inter-recall intervals. Earlier work employing this approach (Rhodes & Turvey, 2007) suggested power law behavior. Long trial durations (1 hour) are employed to more rigorously test for the presence of power law behavior and more generally, the hypothesis that the dynamics of free recall reflect complex, multiplicative processes. The outlined empirical methods are also employed to test predictions about the relative structure of differently sized categories. Consequences for an asymptotic curve based understanding of free recall and foraging metaphors of retrieval are discussed.