Transcranial Magnetic Stimulation for Speech Perception

Overseen By Hannah Olson, MA

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Connecticut

Must not be taking: Antidepressants, Antipsychotics, Antivirals, others

Disqualifiers: Seizure, Metal in skull, Pregnancy, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 1

Duration: 3 weeks

26 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

Left and right temporal brain areas are thought to contribute to speech perception, but the division of labor between left and right hemisphere regions is still unclear. Here we use transcranial magnetic stimulation (TMS) to stimulate left and right temporal foci and a vertex control site to temporarily disrupt activation at the stimulation site, using a "virtual lesion" approach to test the effect of stimulation site on a series of speech perception tasks. This portion of the project is basic research. However, since TMS is viewed as an intervention, studies involving TMS in this grant are considered clinical trials.

Are You a Good Fit for This Trial?

This trial is for monolingual native English speakers with no neurological impairments, speech or language disorders, and mild or better hearing. Participants must be right-handed as confirmed by a handedness inventory.

Inclusion Criteria

I have no history of neurological diseases.

Monolingual native speaker of English

Free of speech and language disorders (per self-report, and confirmed by short language battery described by Fidler, Vance, & Plante, 2011)

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline Assessment

Participants undergo structural MRI and a speech localizer using functional MRI to identify speech-sensitive voxels in the left and right temporal cortex

1 week

1 visit (in-person)

Treatment

Participants receive TMS to disrupt neural activity in the left and right temporal cortex and perform speech perception tasks

3 weeks

Multiple sessions (in-person)

Follow-up

Participants are monitored for any adverse effects and the effectiveness of the TMS intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Transcranial Magnetic Stimulation

Trial Overview The study uses Transcranial Magnetic Stimulation (TMS) on different brain areas to understand their role in speech perception. It aims to create 'virtual lesions' to see how temporary disruption affects the ability to perceive speech.

How Is the Trial Designed?

Group I: Experiment 6: Disruption of talker-specific phonetic learning using TMS. Experimental Treatment 1 Intervention

Experiment 6 is designed to test whether disruption of activity in left or right temporal regions (vs. vertex control) using TMS interferes with talker-specific learning. Participants will receive stimulation at all three sites (left temporal, right temporal, vertex, with order of stimulation counterbalanced across participants). The study uses a training paradigm where one talker's speech is manipulated to always have relatively short voice onset times (VOTs) for voiceless stops (e.g., /k/ in "coal") and another to have relatively long VOTs. Immediately after stimulation, listeners will undergo a training trial where they identify sounds as mapping to Talker 1 or Talker 2's voice, and to the word (e.g. "gain" vs. "cane"). At test, listeners hear two VOT variants and are asked which is more typical of that talker's speech. The dependent variable is the accuracy of reporting which variant is typical of the talker.

Group II: Experiment 3. Phonetic ambiguity in continuous speech Experimental Treatment 1 Intervention

Experiment 3 is designed to test whether left vs. right temporal lobe stimulation selectively disrupts processing of naturally-occurring phonetic ambiguity as compared to vertex stimulation (control). Participants will receive stimulation at all three sites (left temporal, right temporal, vertex, with order of stimulation counterbalanced across participants). Stimuli will be nonsense sentences produced clearly or in a casual register. By-sentence phonetic ambiguity is estimated by the proximity of each token to other vowels belonging to different categories. Sentences will be embedded in speech-shaped noise to increase difficulty. Participants will listen to each sentence, then respond whether a visually-presented probe word appeared in the sentence ("BRASS?"). Dependent variables are accuracy and reaction time on this probe verification task.

Group III: Experiment 2. Phonetic precision disrupted by TMS Experimental Treatment 1 Intervention

Experiment 2 tests the influence of temporary disruption of activity within the left or right temporal cortex on the speed and precision of phonetic decisions compared to vertex stimulation. Participants will receive stimulation at all three sites (left temporal, right temporal, vertex, with order of stimulation counterbalanced across participants). Immediately following stimulation pulses, participants will perform a visual analog scale (VAS) phonetic rating task on tokens from the four continua, embedded in speech-shaped noise. To control for the possibility that TMS leads to a generalized deficit in categorization, a control task will involve categorization of visual objects on a morphed "dog" to "cat" object continuum. (We expect this task to be unaffected by TMS). The variables of interest are the steepness of the categorization curve, mean reaction time to all items on the continuum, and the difference in reaction time for boundary vs. endpoint tokens.

Transcranial Magnetic Stimulation is already approved in United States, Canada, European Union for the following indications:

Approved in United States as Transcranial Magnetic Stimulation for:

• Major Depressive Disorder
• Obsessive Compulsive Disorder

Approved in Canada as Transcranial Magnetic Stimulation for:

• Major Depressive Disorder

Approved in European Union as Transcranial Magnetic Stimulation for:

• Major Depressive Disorder

Who Is Running the Clinical Trial?

University of Connecticut

Lead Sponsor

Trials

194

Recruited

162,000+

National Institute on Deafness and Other Communication Disorders (NIDCD)

Collaborator

Trials

377

Recruited

190,000+