Why Stuttering Occurs: The Role of Cognitive Conflict and Control.

The purpose of this article is to provide a theoretical account of the experience of stuttering that incorporates previous explanations and recent experimental findings. According to this account, stuttering-like disfluencies emerge during early childhood from excessive detection of cognitive conflict due to subtle limitations in speech and language processes. For a subset of children who begin to stutter, the development of approach-avoidance motivational conflict likely contributes to a chronic reliance on cognitive control processes during speech. Consequently, maladaptive activation of right hemisphere inhibitory cortices to the basal ganglia via a hyperdirect pathway results in involuntary, episodic, and transient freezing of the motor system during speech initiation. This freeze response, consistent with defensive behavior in threatening situations, may lead to stuttering persistence, tension and struggle, maladaptive speech physiology, and feelings of anxiety and loss of control.