Proceedings of the Annual Meeting of the Cognitive Science Society

A complete theory of spontaneous thought must explain not only content but also dynamics: how the stream unfolds over time. Recent memory-centric accounts characterize these dynamics as fundamentally associative. I argue that such accounts cannot accommodate goal-structured dynamics: sequences in which successor selection is governed by instrumental relevance to a goal rather than by associative strength. Drawing on evidence from spontaneous planning, I show that goal-structured dynamics genuinely occur within mind wandering. I propose a dual-driver model in which memory and cognitive control jointly generate the stream: memory drives associative drift, while control imposes goal-structured organization when an automatically activated goal recruits executive resources. On this view, the spontaneous stream is heterogeneous, shifting fluidly between associative and goal-structured phases.