The Role of Semantic Clustering in Optimal Memory Foraging

Area of Science:

• Cognitive Psychology
• Neuroscience
• Computational Linguistics

Background:

• Semantic memory search theories often draw parallels with animal foraging strategies.
• Two prominent theories, Lévy flights and the marginal value theorem, offer different explanations for search behavior.
• The role of semantic memory clustering in supporting these foraging theories remains underexplored.

Purpose of the Study:

• To investigate whether semantic memory clustering influences search patterns consistent with animal foraging theories.
• To test if spatial representations of semantic knowledge can elucidate search behaviors.
• To reconcile findings supporting Lévy flights and the marginal value theorem within a unified framework.

Main Methods:

• Elicited spatial representations of animal knowledge using labeled magnets and a whiteboard.
• Analyzed category recall sequences to trace search paths over these spatial representations.
• Correlated spatial distances between semantic items with inter-response intervals (IRIs) during recall.

Main Results:

• Spatial distances between animal names correlated with IRIs during category recall.
• Distributions of spatial distances and IRIs approximated inverse power laws, characteristic of Lévy flights.
• IRIs were shorter upon entering semantic clusters and longer upon exiting, consistent with the marginal value theorem.

Conclusions:

• Area-restricted search within clustered semantic spaces can explain patterns supporting both Lévy flights and the marginal value theorem.
• Semantic clustering provides a unifying mechanism for understanding optimal search in memory.
• This research bridges animal foraging theory and cognitive models of semantic memory.