Is searching memory like searching space? William James once wrote that “We make search in our memory for a forgotten idea, just as we rummage our house for a lost object.” Both space and memory have structure and we can use that structure to zero in on what we are looking for. In searching space, this is easy to see. A person hunting for their lost keys is not unlike a starling scouring the garden for wayward insects. But in searching memory, what is the map? And by what means does a person move from one memory to the next? In this chapter I will lay out the similarities between foraging in space and mind and then describe a research approach inspired by an ecological model of animal forging. Using this approach, we will combine data from a memory production task with a cognitive map – a network representation – of memory derived from natural language. We will then use this to compare a suite of models aimed at teasing apart how memory search is similar to our garden starling.

An important adaptive problem for humans and other animals is the acquisition of food. To study foraging strategies, human behavioral ecologists use a number of optimization models, which generally assume that individuals aim to maximize the rate at which they acquire resources. For instance, the prey choice model and its variants highlight the resources that should either be pursued or ignored when they are encountered. The patch choice model and the marginal value theorem, respectively, examine which patches should be exploited by foragers and when they should switch from one patch to another. Foraging strategies are impacted by social considerations, too. The ideal free distribution considers the habitats that foragers should choose while considering the suitability of possible habitats as a function of the number of current occupants. Diverse case studies from ethnographic and archaeological research are discussed. The chapter also highlights opportunities for future studies, including research on the social dimensions of foraging strategies and the ways in which humans can modify environments to enhance foraging returns. There is also a clear need for additional research on the causes and consequences of individual-level variation in foraging ability.

Information-seeking is usually conceived of as gathering information to make better decisions by observing and sampling from the external world. But for humans and many other intelligent agents, much of that information, once gathered, is also stored to guide future decisions, necessitating mechanisms for seeking information in some form of inner space. Here we survey various types of evidence suggesting that strategies adapted for search in external spatial environments are also used to seek information internally from memory. These include foraging strategies such as area-restricted search, which adaptively balances exploitation of locally clustered resources with exploration for resources more widely dispersed. We also describe how internal search satisfies the predictions of external foraging theory via the Marginal Value Theorem and show how these predictions can be used to investigate individual differences in memory search such as those caused by aging and cognitive impairment. Finally, we consider evidence that the structure of inner space may be a result of the very processes we use to search it.