>*"All you're talking about is reward prediction error. There are no studies looking at this."* As you may know, I enjoy summarizing modern stuttering hypotheses from various Phd researchers and integrating them into broader models. One hypothesis that I find particularly intriguing is by researcher Evan Usler, PhD. His work focuses on the concept of prediction errors in stuttering. You can find his research here: * [Direct PDF Download](https://osf.io/uph5g/download/?format=pdf) * [ResearchGate Profile](https://www.researchgate.net/profile/Evan-Usler) Having read his all research material thoroughly, I highly recommend it for anyone interested in prediction errors in stuttering. This is my interpretation of the core principles underlying his hypothesis: According to Dr. Usler (Phd), stuttering arises due to the following mechanisms: * Neurological or psychological factors: e.g., A tendency to be more cautious to prevent speech errors * which increases cognitive conflict: e.g., giving a public speech despite fear of social evaluation * which reduces perceived communication competence and sense of self-efficacy * which increases the BIS (behavioral inhibition system) * which leads us to try to resolve cognitive conflict by prioritizing controlled processes over automatic processes & relying on aberrantly high sensory precision to speech-related predictions * which results in Salient prediction errors & Excessively precise prior beliefs about the likelihood of stuttering * stuttering occurs (aka inhibition in syllable initiation ) * which results in: hypervigilance, anxiety, cautiousness, autonomic arousal, and the momentary slowing of behavior. Over time, anticipatory anxiety, physical tension, and the feeling of loss of control become habitual (*in response to the chronic cognitive conflict and transient freezing of speech initiation*) * habitual persistence leads to a vicious circle that prevents stuttering remission Prediction errors: * It’s the mismatch between expected and actual sensory input. The mismatch between what the brain anticipates (based on its internal model or prior beliefs) and what is actually perceived (sensory input received from the environment).