Auditory Prediction and Error Evaluation in the Speech of Individuals Who Stutter

BEHAVIORAL

Delaying speech initiation

This intervention will examine the effects of misalignment between prediction and auditory feedback in participants. We will use transcranial magnetic stimulation to induce a temporal misalignment between prediction and auditory feedback while participants produce speech.

BEHAVIORAL

Auditory errors and pre-speech auditory modulation

This intervention will examine the contributions of auditory errors to pre-speech auditory modulation. Participants will receive auditory perturbations while speaking, and we will collect their brain activities throughout the study.

BEHAVIORAL

Contributions of the speech premotor cortex to pre-speech auditory modulation

This intervention will examine the effects of stimulation of the left ventral premotor cortex on pre-speech auditory modulation. Participants will receive electrical stimulation while speaking.

BEHAVIORAL

Delaying auditory feedback

This intervention will examine the effects of misalignment between prediction and auditory feedback in participants. We will use delayed auditory feedback to induce a temporal misalignment between prediction and auditory feedback while participants produce speech.

Change in brain activity before and during speaking

Time frame: within each session of the study that may last up to 2 hours

Participants will hear speech sounds in each trial before speaking or reading words. Participants' brain activity will be recorded while completing the speaking or reading tasks. The investigators will measure how the participant's brain activity in response to the played sounds changes during speaking and reading tasks. For this purpose, the investigators will measure the amplitude of the brain activity (in microvolts; µV) measured using a commercial electroencephalography system. The amplitude (µV) of the brain signals will be examined both before speaking and during speaking at two time points.

change in speech when participants experience auditory errors

Time frame: within each session of the study that may last up to 2 hours

In each trial, participants will experience an auditory error while they produce speech (e.g., they may say "head" but hear "had"). The investigators will measure how the participants' speech changes due to auditory errors that they experience in the current trial. For this p\[purpose, the investigators will use commercial microphones to record speech signals and then examine the amplitude of the speech in specific frequency ranges (measured in Hertz; Hz). The frequencies (Hz) of speech in trials with auditory errors will be compared with those without auditory errors.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.