title: Hidden processes in structural representations: A reply to Abbott, Austerweil, and Griffiths (2015).
abstract: In recent work exploring the semantic fluency task, we found evidence indicative of optimal foraging policies in memory search that mirror search in physical environments. We determined that a 2-stage cue-switching model applied to a memory representation from a semantic space model best explained the human data. Abbott, Austerweil, and Griffiths demonstrate how these patterns could also emerge from a random walk applied to a network representation of memory based on human free-association norms. However, a major representational issue limits any conclusions that can be drawn about the process model comparison: Our process model operated on a memory space constructed from a learning model, whereas their model used human behavioral data from a task that is quite similar to the behavior they attempt to explain. Predicting semantic fluency (e.g., how likely it is to say cat after dog in a sequence of animals) from free association (how likely it is to say cat when given dog as a cue) should be possible with a relatively simple retrieval mechanism. The 2 tasks both tap memory, but they also share a common process of retrieval. Assuming that semantic memory is a network from free-association behavior embeds variance due to the shared retrieval process directly into the representation. A simple process mechanism is then sufficient to simulate semantic fluency because much of the requisite process complexity may already be hidden in the representation. (PsycINFO Database Record
authors.affiliation: Cognitive Science Program, Indiana University.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Jones
authors.affiliation: Department of Psychology, University of Warwick.
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Hills
authors.affiliation: Cognitive Science Program, Indiana University.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Todd
mesh_terms: D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008960:Models, Psychological; D011582:Psychological Theory