Chapter 10 - Cognitive, Emotional, and Behavioral Inflexibility and Perseveration in Neuropsychiatric Illness

Abstract

Cognitive and behavioral flexibility is a core adaptive function of the executive control system in the human brain. Executive functions include a set of processes that allow for context-appropriate volitional control in “nonroutine situations.” Goal-directed behavior requires not only an ability to represent a goal and then generate a plausible sequence of actions that must be accomplished to achieve it but also an ability to prioritize goals (represent the relative value of various goals at a given time), initiate a goal-directed process, and maintain goal pursuit in the face of unexpected environmental factors that might otherwise command attention. Too much environmental dependency will result in distractibility, a tendency for tasks to be interrupted, and, ultimately, an inability to complete a complex task sequence aimed toward a particular goal. This can manifest clinically as impulsivity, where the individual quickly shifts tasks in response to a novel stimulus, leaving the prior task sequence incomplete. However, one must also be able to discontinue an activity, switching to a different task when appropriate. An excessively rigid adherence to a predetermined task sequence or a previously valued goal prevents an individual from appropriately responding to changing environmental contingencies. We examine a variety of forms of cognitive, emotional, and behavioral perseveration in neuropsychiatric disease, and explore the various mechanisms believed to account for these phenomena. In many neuropsychiatric illnesses, impairments of flexibility in one form or another account for a significant restriction in the range of reactions, feelings, and self-generated behaviors an individual may exhibit, leading to a breakdown in social and occupational functioning, and in many cases, significant suffering. Perseveration, in its broadest conceptualization, can occur at a variety of levels of organization from simple motor behaviors (i.e., tics), verbal utterances, complex cognitions (i.e., obsessions in obsessive compulsive disorder, perseverative rumination in mood and anxiety disorders, fixed delusions in psychosis), complex behaviors (i.e., compulsions in obsessive compulsive disorder and addiction), and perseveration of affect in mood and anxiety disorders.