This chapter considers what mental actions are, and how they are best explained. Mental actions are shown to include mental rehearsal of actions, prospective imagining, inner speech, attention, memory search, and (perhaps surprisingly) the spontaneous thoughts that occur while mind-wandering, as well as creative ideas that seemingly occur to one “out of the blue.” The chapter also discusses how controlled sequences of mental action can be explained, and discusses events like judgments and decisions that armchair-philosophers have been apt to claim are mental actions, but really are not.

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.