Stuttering

This research is studying the use of low-intensity focused ultrasound (LIFU; a mild, noninvasive acoustic stimulation technique) in a small number of people to learn about its safety as a treatment for stuttering. LIFU is a small, safe sound signal that produces a gentle, pulsing flow of acoustic waves to help different parts of the brain communicate with each other. Researchers want to understand how the mild, non-invasive brain stimulation affects speech relevant brain areas, which may in turn affect speech fluency and speaking-related brain activity in people who stutter.

Stuttering is a common fluency disorder characterized by involuntary interruptions in speech flow, such as repetitions, prolongations, and blocks. It affects approximately 1% of the world's population and typically emerges in the early stages of language development, particularly in preschool. The exact cause of stuttering is still unknown, but it is believed to involve various combinations of genetic, developmental, environmental, and neurophysiological factors (Yairi and Ambrose, 2013). Stuttering not only affects an individual's communication skills but can also significantly impact their psychological and emotional state. Individuals may experience persistent anxiety about being ridiculed or negatively evaluated by others during stuttering episodes, and the pressure to speak fluently in everyday situations can create significant stress and anxiety (Guitar, 2013). The ICF model, developed by the World Health Organization, suggests examining an individual's health status not only at the biological level but also in the context of activity, participation, and environmental factors (WHO, 2001). In particular, the ICF-based model proposed by J. Scott Yaruss and Robert W. Quesal for stuttering offers an important framework for explaining the impact of stuttering on an individual's quality of life. In this context, stuttering is characterized by limited participation in social and professional life in terms of the level of participation (Yaruss \& Quesal, 2004). Individuals with stuttering may experience a number of problems in their professional lives. Job interviews can be given as an example of these situations. Job interviews are an important starting point in the employment process. Job interviews are a situation that creates anxiety and causes avoidance behaviors for individuals with stuttering (Hohulin et al., 2010). Anxiety is defined as "unease, irrational fear, anxiety, worry, distress caused by an unknown danger, misfortune, fear or expectation originating from the unconscious" (Bakırcıoğlu, 2016: 893). When adult individuals with stuttering are faced with a socially threatening, anxiety-inducing environment, they show physical strain and their anxiety increases during stuttering (Bloodstein, 1995; Craig, 2003). The literature reports a positive correlation between threatening or challenging stimuli and the severity of stuttering. For example; Stuttering is observed to increase when speaking to an authority figure, a group, or impatient or critical listeners (Guitar, 2013). Conversely, the frequency of stuttering generally decreases in non-anxiety-inducing situations, such as speaking to a familiar person or someone who is not an authority figure (Craig, 2006). Furthermore, speakers with severe stuttering are more likely to be subjected to negative evaluations and labeling/stigmatization compared to speakers with less severe stuttering (Gabel, 2006). The fear of negative evaluation is defined by Leary (1983) as the individual being evaluated negatively and hostilely by others, or being stigmatized. Stigmatization, in turn, is described as a multidimensional phenomenon encompassing negative attitudes and behaviors towards individuals (Corrigan \& Watson, 2002). The literature includes various therapies for stuttering and the accompanying negative emotional states. One of these approaches is known as desensitization. Desensitization for stuttering is considered an important component of therapy for individuals who stutter. According to most research findings in foreign literature, individuals with stuttering perceive job interviews as a difficult area (Bricker-Katz, Lincoln, and Cumming, 2013; Klein and Hood, 2004; Rice and Kroll, 2006). Furthermore, while many studies focus on the working lives of individuals with stuttering, there are only a few studies specifically addressing job search processes and interviews. No studies addressing job interviews for individuals with stuttering have been found in the local literature. Due to this gap in the literature, our research aims to contribute to the literature and guide future studies in this area. Our study will develop a 10-week desensitization-based therapy program and aims to examine the effects of this structured program on stuttering frequency, fear of negative evaluation, internalized stigma, and anxiety experienced during interviews for individuals with stuttering.

The overall objective of this study is to examine inter effector areas (IEAs) activity and functional connectivity during continuous speech production in stuttering adults.

The goal of this longitudinal research is to learn why some children "grow out" of stuttering, while others persist. Children who do and do not stutter aged 3-6 years are eligible to participate in our study. During the study, children's speech and language abilities will be assessed with standardized assessments, and they complete several child-friendly experiments. During these experiments, brain activity will be recorded using specialized caps while children describe pictures, children will speak in two virtual-reality scenarios, and produce speech while keeping to a beat.

The goal of this study is to find out whether a type of noninvasive brain stimulation can help reduce speech errors, such as repetitions, blocks, and prolongations, in people who stutter. This pilot study will help researchers design future treatments to see if targeting certain brain areas can improve speech fluency. The study will look at how people speak and behave during both speaking and non-speaking tasks before and after the brain stimulation. Participants will complete an online survey about 24 hours before coming to the clinic. The clinic visit will last about 3 hours and will include three phases. All parts of the study will be audio-recorded. 1. Pre-Testing: Participants will first complete a stuttering evaluation to determine whether they are typical speakers or have a mild, moderate, or severe stutter. Then, they will do several speaking and non-speaking tasks. 2. Brain Stimulation: Participants will receive a session of targeted noninvasive brain stimulation (HD-tDCS). 3. Post-Testing: After the brain stimulation, participants will repeat the same evaluation and tasks they completed during pre-testing. Brain stimulation description: HD-tDCS is a non-invasive technique that requires the placement of several sensors (metal electrodes) on a special cap and saline gel on your head. Very low levels of constant electrical current are delivered to specifically targeted areas of the brain via these electrodes. You may experience a slight feeling of dizziness when starting the stimulation. This occurs in a small number of subjects. This takes only a few seconds and does not affect balance after the stimulation has been completed. Several research centers have previously investigated the use of this device on healthy subjects and have found the device to be safe with no direct effect on the person's well-being. Following stimulation, participants will have the opportunity to rinse out residual gel from hair and scalp.

This Phase 2a clinical trial is an open-label, single-group, within-subjects pilot study designed to evaluate the safety, feasibility, and preliminary efficacy of psilocybin as a therapeutic intervention for adults with developmental stuttering. This pilot study will assess whether further research to explore the potential benefits of psilocybin-assisted therapy for improving clinical outcomes in individuals who stutter, is warranted. The aims of this study include: * Aim 1: Assess the safety and feasibility of psilocybin as a therapeutic agent for stuttering. * Aim 2: Evaluate the effects of psilocybin on objective and subjective measures of stuttering severity, struggle, and well-being. * Aim 3: Explore the therapeutic neural mechanisms of psilocybin in stuttering.

The purpose of this study is to collect preliminary data on the efficacy of transcranial direct current stimulation (tDCS) combined with traditional behavioral techniques to reduce stuttering severity and negative impact in adults who stutter. The study also aims to explore neuroplastic changes (i.e., regional activation and functional connectivity) resulting from combined tDCS + speech therapy.

The specific purpose of this clinical trial is to compare performance on rhythm perception and production tasks between children who stutter and children who do not stutter. The overall project also aims to investigate how performance on rhythm tasks may be related to brain activity (non-clinical trial).

The purposes of this study are to 1) investigate potential speech, language, and psychosocial contributions to the experience of stuttering in monolingual and multilingual speakers, and to 2) evaluate interdisciplinary, telehealth, and speech-language pathology treatment methods and clinical training specific to fluency disorders.