Thank you for your thoughtful and insightful reply! I’m really enjoying our conversation too. Regarding the research sources cited in the VRT summary, most are derived from the following research works: \- Book: "The perfect stutter" \- Perfectionism and stuttering: Findings of an online survey \- Revisiting Bloodstein’s Anticipatory Struggle Hypothesis from a psycholinguistic perspective: A Variable Release Threshold Hypothesis of stuttering \- Stuttering prevalence, incidence and recovery rates depend on how we define it: Comment on Yairi & Ambrose’ article Epidemiology of stuttering: 21st century advances \- The influence of anticipation of word misrecognition on the likelihood of stuttering \- Investigating the inner speech of people who stutter: Evidence for (and against) the Covert Repair Hypothesis \- A review of evidence for the Covert Repair Hypothesis of stuttering \- Stuttering, Dopamine and Incentive Learning \- The Variable Release Threshold (VRT) Hypothesis of Stuttering \- Reviewing the Covert Repair Hypothesis \- A clinical adaptation of the Covert Repair Hypothesis by a person who stutters > *"The evidence for dopamine dysregulation is mainly in elevated dopamine levels, rather than reductions."* > Regarding your statement, *“The evidence for dopamine dysregulation is mainly in elevated dopamine levels, rather than reductions,”* I agree with much of what you said. I believe you’re referring to **pre-synaptic tonic dopamine** (long-term effects) rather than the more immediate, phasic post-synaptic dopamine fluctuations. The VRT hypothesis indeed suggests that both forms of dysregulation are associated with developmental stuttering, with pre-synaptic dopamine (likely what you’re referencing) being considered the root or underlying cause of stuttering, as per the VRT hypothesis. >You said, "Rewarding: it dampens our sensitivity so that the rises in synaptic dopamine are no longer so rewarding" That's not possible. A rewarding stimulus elicits a rise in dopamine, rather than dopamine eliciting a pleasurable feeling. You mentioned, *“Rewarding: it dampens our sensitivity so that the rises in synaptic dopamine are no longer so rewarding.”* I’d like to clarify that a rewarding stimulus elicits a rise in dopamine rather than dopamine itself producing a pleasurable feeling. If a novel stimulus is deemed rewarding, the resulting spike in synaptic dopamine tends to be prolonged and heightened, facilitating further approach behavior toward the stimulus. Similarly, any stimulus that generates anticipation of a primary reward also causes a phasic spike in synaptic dopamine, which reinforces approach behavior toward the anticipated reward, an idea supported by the VRT hypothesis. Additionally, I found the study *Stuttering, Dopamine, and Incentive Learning* particularly helpful in deepening my understanding of these mechanisms: [Stuttering, Dopamine and Incentive Learning](https://www.researchgate.net/publication/352029918_STUTTERING_DOPAMINE_AND_INCENTIVE_LEARNING)