Clinical Research Directory

Vowel Space Expansion Sensorimotor Adaptation

The purpose of this research study is to understand how the brain processes and controls speech in healthy people. The investigators are doing this research because it will help identify the mechanisms that allow people to perceive their own speech errors and to learn new speech sounds. 117 participants will be enrolled into this part of the study and can expect to be on study between 1 day (Experiment 1) and 4 weeks (Experiment 2).

Velopharyngeal Insufficiency After Maxillomandibular Advancement Osteotomy in Obstructive Sleep Apnea Patients

The aim of this study is to gain insight into the development of velopharyngeal insufficiency (VPI) in patients who have undergone maxillomandibular advancement osteotomy (MMA) as a treatment for obstructive sleep apnea syndrome (OSAS). A speech therapist evaluates nasality, speech, and swallowing before and after the surgery.

Research on Speech Development Trajectories and Predictive Models in Children With Autism Spectrum Disorder

Recent studies indicate that children with ASD have a significantly higher risk of co-occurring speech sound disorders than typically developing children. Early atypical speech development may be a critical yet overlooked bottleneck hindering their language improvement. Given the unique phonetic features of Mandarin, it is essential to investigate speech development in Mandarin-speaking children with ASD. This study aims to construct developmental trajectories and establish early identification and prognosis prediction models for this population.

Speech Motor Learning and Retention (Master Protocol)

The overall goal of this research is to test a new model of speech motor learning, whose central hypothesis is that learning and retention are associated with plasticity not only in motor areas of the brain but in auditory and somatosensory regions as well.

Speech Motor Learning and Retention (Aim 2)

The overall goal of this research is to test a new model of speech motor learning, whose central hypothesis is that learning and retention are associated with plasticity not only in motor areas of the brain but in auditory and somatosensory regions as well. The strategy for the proposed research is to identify individual brain areas that contribute causally to retention by disrupting their activity with transcranial magnetic stimulation (TMS). Investigators will also use functional magnetic resonance imaging (fMRI) which will enable identification of circuit-level activity which predicts either learning or retention of new movements, and hence test the specific contributions of candidate sensory and motor zones. In other studies, investigators will record sensory and motor evoked potentials over the course of learning to determine the temporal order in which individual sensory and cortical motor regions contribute. The goal here is to identify brain areas in which learning-related plasticity occurs first and which among these areas predict subsequent learning.

Speech Motor Learning and Retention (Aim 1)

The overall goal of this research is to test a new model of speech motor learning, whose central hypothesis is that learning and retention are associated with plasticity not only in motor areas of the brain but in auditory and somatosensory regions as well. The strategy for the proposed research is to identify individual brain areas that contribute causally to retention by disrupting their activity with transcranial magnetic stimulation (TMS). Investigators will also use functional magnetic resonance imaging (fMRI) which will enable identification of circuit-level activity which predicts either learning or retention of new movements, and hence test the specific contributions of candidate sensory and motor zones. In other studies, investigators will record sensory and motor evoked potentials over the course of learning to determine the temporal order in which individual sensory and cortical motor regions contribute. The goal here is to identify brain areas in which learning-related plasticity occurs first and which among these areas predict subsequent learning.

Virtual Reality as a Tool for Training Public Speaking Skills in Higher Education Students

According to the scientific literature, public speaking (PS) is an important skill for students to master. However, a large proportion of students do not feel comfortable speaking in public. PS anxiety impacts oral communication (i.e., voice and fluency). These changes can affect speaker's academic and professional success, as well as his credibility. Performing a high-quality PPP with confidence is therefore rarely an innate skill, but fortunately it can be trained and improved. Therefore, training PS skills in representative settings is crucial but often challenging for PS professionals (e.g., speech therapists, vocologists, coaches). This project examines how oral communication skills training including simulations in virtual reality (VR) supports the acquisition of effective oral PS skills. Using acoustic analyses, outcomes from participants in the intervention group (N = 40) will be compared with those of a wait-list control group (N = 40) to determine whether significant differences emerge in filled pauses, speech rate, and vocal intonation during PS. Changes in PS self-efficacy will also be assessed. Regarding secondary outcomes, the study will evaluate changes in self-reported and physiological PS anxiety, as well as self-reported confidence as a speaker. Finally, self-perceived vocal effort during PS will be examined.

Speech Motor Learning and Retention (Aim 3)

The overall goal of this research is to test a new model of speech motor learning, whose central hypothesis is that learning and retention are associated with plasticity not only in motor areas of the brain but in auditory and somatosensory regions as well. The strategy for the proposed research is to identify individual brain areas that contribute causally to retention by disrupting their activity with transcranial magnetic stimulation (TMS). Investigators will also use functional magnetic resonance imaging (fMRI) which will enable identification of circuit-level activity which predicts either learning or retention of new movements, and hence test the specific contributions of candidate sensory and motor zones. In other studies, investigators will record sensory and motor evoked potentials over the course of learning to determine the temporal order in which individual sensory and cortical motor regions contribute. The goal here is to identify brain areas in which learning-related plasticity occurs first and which among these areas predict subsequent learning.

The Neural Coding of Speech Across Human Languages

The overall goal of this study is to reveal the fundamental neural mechanisms that underlie comprehension across human spoken languages. An understanding of how speech is coded in the brain has significant implications for the development of new diagnostic and rehabilitative strategies for language disorders (e.g. aphasia, dyslexia, autism, et alia). The basic mechanisms underlying comprehension of spoken language are unknown. Researchers are only beginning to understand how the human brain extracts the most fundamental linguistic elements (consonants and vowels) from a complex and highly variable acoustic signal. Traditional theories have posited a 'universal' phonetic inventory shared by all humans, but this has been challenged by other newer theories that each language has its own unique and specialized code. An investigation of the cortical representation of speech sounds across languages can likely shed light on this fundamental question. Previous research has implicated the superior temporal cortex in the processing of speech sounds. Most of this work has been entirely carried out in English. The recording of neural activity directly from the cortical surface from individuals with different language experience is a promising approach since it can provide both high spatial and temporal resolution. This study will examine the mechanisms of phonetic encoding, by utilizing neurophysiological recordings obtained during neurosurgical procedures. High-density electrode arrays, advanced signal processing, and direct electrocortical stimulation will be utilized to unravel both local and population encoding of speech sounds in the lateral temporal cortex. This study will also examine the neural encoding of speech in patients who are monolingual and bilingual in Mandarin, Spanish, and English, the most common spoken languages worldwide, and feature important contrastive differences of pitch, formant, and temporal envelope. A cross-linguistic approach is critical for a true understanding of language, while also striving to achieve a broader approach of diversity and inclusion in neuroscience of language.

Intelligibility and Acoustic Speech Performance of CAD/CAM Milled Titanium Partial Dentures

Partial dentures play a crucial role in restoring oral function and aesthetics for patients with missing teeth. Traditionally, these prostheses have been fabricated using materials such as acrylic resin or cobalt-chromium alloys. However, advancements in digital dentistry have introduced new materials and manufacturing techniques, including computer-aided design and computer-aided manufacturing (CAD/CAM) milled titanium. While titanium offers advantages such as biocompatibility, lightweight properties, and corrosion resistance, its impact on speech performance remains understudied.

Talk With Me Baby to Enhance the Early Home Language Environment

The goal of this clinical trial is to learn if the Talk With Me Baby (TWMB) program improves the home-language environment for at-risk families with children ages two to six months when primary care providers deliver the program during well-child checkups. The main question it aims to answer is: Will the TWMB program increase the time a caregiver talks to their infant? Participants will: 1. Come to at least four well-child checkups 2. Receive the TWMB program from the provider during the checkups 3. Record their conversations with their infant before they receive the program and after they receive the program four times.

Functional Organization of the Superior Temporal Gyrus for Speech Perception

The basic mechanisms underlying comprehension of spoken language are still largely unknown. Over the past decade, the study team has gained new insights to how the human brain extracts the most fundamental linguistic elements (consonants and vowels) from a complex and highly variable acoustic signal. However, the next set of questions await pertaining to the sequencing of those auditory elements and how they are integrated with other features, such as, the amplitude envelope of speech. Further investigation of the cortical representation of speech sounds can likely shed light on these fundamental questions. Previous research has implicated the superior temporal cortex in the processing of speech sounds, but little is known about how these sounds are linked together into the perceptual experience of words and continuous speech. The overall goal is to determine how the brain extracts linguistic elements from a complex acoustic speech signal towards better understanding and remediating human language disorders.

Impact of Anterior Cross Bite Treatment on Children's Speech Performance

The goal of this prospective, single-arm clinical trial is to evaluate the speech performance of children with anterior dental crossbite before and after correction. Also, to assess the impact of early interceptive orthodontic treatment in the mixed dentition stage to correct the anterior dental crossbite on the quality of life of children. Fifty children of both sexes aged from 8 to 10 years were enrolled and evaluated using the study's inclusion \& exclusion criteria. before beginning interceptive orthodontic treatment, each child underwent full mouth treatment. then, using a removable anterior expansion screw along with posterior bite planes to treat the anterior crossbite. All children were subjected to the Protocol of speech evaluation before appliance insertion and after complete correction of anterior crossbite. Also, the Child Perceptions Questionnaire (CPQ 8-10) in the Brazilian version was used to gauge how the anterior crossbite affected the children's oral health-related quality of life.

Elicitation of Steady-state Audiovisual Responses in 6- and 10-month-old Infants

The goal of this study is to investigate the preferential responses of speech neural systems in infants. The main question it aims to answer is to determine whether the oscillatory synchronization capacity is associated with children's language level (i.e. vocabulary). Participants will be presented with synthetically modulated stimuli at three frequency scales: 4 Hz, 5 Hz and 30 Hz.

Effects of Clear Speech on Listening Effort and Memory in Sentence Processing

Sensorineural hearing loss (SNHL) is among the most prevalent chronic conditions in aging and has a profoundly negative effect on speech comprehension, leading to increased social isolation, reduced quality of life, and increased risk for the development of dementia in older adulthood. Typical audiological tests and interventions, which focus on measuring and restoring audibility, do not explain the full range of cognitive difficulties that adults with hearing loss experience in speech comprehension. For example, adults with SNHL have to work disproportionally harder to decode acoustically degraded speech. That additional effort is thought to diminish shared executive and attentional resources for higher-level language processes, impacting subsequent comprehension and memory, even when speech is completely intelligible. This phenomenon has been referred to as listening effort (LE). There is a growing understanding that these cognitive factors are a critical and often "hidden effect" of hearing loss. At the same time, the effects of LE on the neural mechanisms of language processing and memory in SNHL are currently not well understood. In order to develop evidence-based assessments and interventions to improve comprehension and memory in SNHL, it is critical that the cognitive and neural mechanisms of LE and its consequences for speech comprehension are elucidated. In this project, the investigators adopt a multi-method approach, combining methods from clinical audiology, psycholinguistics, and cognitive neuroscience to address this gap of knowledge. Specifically, the investigators adopt a novel and innovative method of co-registering pupillometry (a reliable physiological measure of LE) and language-related event-related brain potential (ERP) measures during real-time speech processing to characterize the effects of clear speech (i.e., a listener-oriented speaking style that is spontaneously adopted to improve intelligibility when speakers are aware of a perception difficulty on behalf of the listener) on high-level language processes (e.g., semantic retrieval, syntactic integration) and subsequent speech memory in older adults with SNHL. This innovative work addresses a time-sensitive gap in the literature regarding the identification of objective and reliable markers of specific neurocognitive processes impacted by speech clarity and LE in age-related SNHL.

Neural Mechanisms for Stopping Ongoing Speech Production

Speech and communication disorders often result in aberrant control of the timing of speech production, such as making improper stops at places where they should not be. During normal speech, the ability to stop when necessary is important for maintaining turn-taking in a smooth conversation. Existing studies have largely investigated neural circuits that support the preparation and generation of speech sounds. It is believed that activity in the prefrontal and premotor cortical areas facilitates high-level speech control and activity in the ventral part of the sensorimotor cortex controls the articulator (e.g. lip, jaw, tongue) movements. However, little is known about the neural mechanism controlling a sudden and voluntary stop of speech. Traditional view attributes this to a disengagement of motor signals while recent evidence suggested there may be an inhibitory control mechanism. This gap in knowledge limits our understanding of disorders like stuttering and aphasia, where deficits in speech timing control are among the common symptoms. The overall goal of this study is to determine how the brain controls the stopping of ongoing speech production to deepen our understanding of speech and communication in normal and impaired conditions.

Social Influences on Sensorimotor Integration of Speech Production and Perception During Early Vocal Learning

The goal of this study is to investigate the role of social factors on speech learning, including production and perception, in infants ranging in age from \~7-18 months. Infants have either typical hearing or sensorineural hearing loss. The main prediction of the study is that social reinforcement will engender improvements in vocal learning above and beyond gains in hearing in infants with hearing loss. As part of this study: * The parent and infant engage in a free play session in the playroom while the investigator cues the parent to say simple nonsense words; * Infants hear playback of the same words during a second phase.

Behavioral and Neural Characteristics of Adaptive Speech Motor Control

This study meets the NIH definition of a clinical trial, but is not a treatment study. Instead, the goal of this study is to investigate how hearing ourselves speak affects the planning and execution of speech movements. The study investigates this topic in both typical speakers and in patients with Deep Brain Stimulation (DBS) implants. The main questions it aims to answer are: * Does the way we hear our own speech while talking affect future speech movements? * Can the speech of DBS patients reveal which brain areas are involved in adjusting speech movements? Participants will read words, sentences, or series of random syllables from a computer monitor while their speech is being recorded. For some participants, an electrode cap is also used to record brain activity during these tasks. And for DBS patients, the tasks will be performed with the stimulator ON and with the stimulator OFF.