Multi-plasticities: Distinguishing context-specific habits from complex perseverations

Though perseveration and habit have always been understood as distinct phenomena, they have also been closely linked throughout the history of their scientific study. Seminal work, in particular in the study of lesions and neurological disorders, has described symptomatic errors of commission as being a form of one or the other (Sandson & Albert, 1984), sometimes with disagreement among researchers. More recently, researchers have explored the idea that the formal mathematical framework used to describe the learning and dynamics of habits may also, and perhaps more accurately, be used to understand the emergence and utility of perseverative responding (Gershman, 2020). An explicit lesson from this work is that claims to measure putative habitual behavior would do well to take into account the contribution of one or more types of perseveration. Thus, it makes sense to review the current state of understanding of perseveration, both to draw distinctions of difference with habits, where they are possible, and to outline areas of potential further research. This chapter briefly summarizes the classical conception of perseveration, including conceptual underpinnings and empirical research. We then examine how this conception has evolved via both empirical and theoretical advances. We summarize these findings into a taxonomy of types of perseverative behavior, and describe recent work arguing for an adaptive role of perseveration in multiple forms of cognition. We argue that perseveration is a complex set of constructs that have widespread influence on behavior, with important implications for the experimental measurement of habits and compulsive responding.