Epilepsy, Speech
Conditions
Brief summary
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.
Detailed description
Intracranial electroencephalography (iEEG) is a state-of-the-art technique with fine spatial and temporal resolutions that are well suited for studying the neural dynamics of speech. This study proposes to assess speech production in patients who are undergoing iEEG recording to carry out clinical procedures for indications related to their medical condition. The research study team will investigate neural signals correlated with speech stopping using speech production and stopping tasks with visual cues. The research study team will compare effects on neural activity within each individual subject and identify common patterns of activity across subjects. The aims of this study seek to determine the role of the premotor network for stopping during naturalistic usage. This study will provide basic knowledge for the precise control of speech stopping and the control of speech timing in general, bridging the current speech production studies to real-world communication conditions, and help inspire new theories of speech motor control.
Interventions
BEHAVIORALSpeech Production Tasks
View visual cues and undergo speech production.
Sponsors
Lingyun Zhao
National Institute on Deafness and Other Communication Disorders (NIDCD)
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
8 Years to 26 Years
Healthy volunteers
No
Inclusion criteria
* Undergoing iEEG placement in regions of interest (e.g., in the frontal or temporal cortex) for clinically necessary localization of epileptic foci or language mapping * Fluent English speakers * Within the normal range for cognitive, speech-language, and hearing capacity * Normal or corrected-to-normal visual acuity
Exclusion criteria
* Individuals with intellectual disability * Lack of fluent English comprehension/production * Inadequate speech ability for the research tasks. * History of autism or ADHD
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean Change in Neural Activity | During inpatient hospitalization, up to 14 days after surgical electrode implantation | Neural signal recorded at each electrode (measured in voltage) is bandpass-filtered and converted to analytic amplitude using Hilbert transform, and then Z-scored relative to the entire recording block period for that electrode. A Z-score of 0 represents the mean neural activity within the recording block period, during which the task is performed. A positive Z-score indicates higher neural activity compared to the block mean. The mean change in neural activity was calculated as the difference between the average Z-score in two time windows (\~1 second after the visual cue vs. \~1 second before), averaged across trials for each electrode and then across electrodes from all participants. Positive values of the mean change in neural activity indicate that neural activity was increased after the visual cue. Since the Z-score used here is a normalized neurophysiological measure rather than a clinical scale, there are no established thresholds or definitions of better or worse outcomes. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORLingyun Zhao, PhD
University of Pittsburgh
Outcome results
None listed