Neural Bases of Speech PerceptionNCT04989309
Left and Right Hemisphere Contributions to Speech Perception
A study testing Transcranial Magnetic Stimulation in people with Neural Bases of Speech Perception, run by University of Connecticut at 1 site in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Neural Bases of Speech Perception
- What is being tested?
- Transcranial Magnetic Stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 26 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Dec 2024to 30 Jun 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Monolingual native speaker of English
- No history of neurological impairments or disease
- Free of speech and language disorders (per self-report, and confirmed by short language battery described by Fidler, Vance, \& Plante, 2011)
- Pure-tone thresholds of 30 decibels or better in both ears (no worse than mild hearing loss), with no more than 15 dB between-ear difference.
- Right-handed, as confirmed by Oldfield Handedness Inventory
Who cannot join
- Any condition where TMS would be contraindicated according to the most recent guidelines, including, but not limited to:
- History of seizure or epilepsy
- Metal in the skull
- Use of legal or illicit drugs that can potentially reduce the threshold for seizure. As examples, we list some exclusionary drugs in each of the following categories. This is not an exhaustive list of the exclusionary drugs. We consult with faculty in the University of Connecticut College of Pharmacy to check for seizure risk with other drugs that participants report.
- Antidepressants including Imipramine, amitriptyline, sertraline, venlafaxine, buproprion
- Antipsychotics including Chlorpromazine, clozapine, haloperidol, aripiprazole
Show all 16Show fewer
- Antivirals including foscarnet, ganciclovir
- Antiparasitics including chloroquine, mefloquine (antiparasitics)
- Antibiotics including penicillin, ampicillin
- Immunosuppressants including cyclosporin
- Anticholinergenics
- Antihistimines (including over-the-counter drugs like Claritin \& Benadryl)
- Sympathomimetics (including Sudafed, Ritalin).
- Illegal drugs such as methamphetamines, cocaine, MDMA, ketamine.
- Diagnosis of a psychiatric disorder (per self-report)
- Pregnancy
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
University of Connecticut
Storrs, Connecticut, 06268
About this study
Official title: The Role of Frontal and Temporal Brain Areas in the Perception of Phonetic Category Structure
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.
Read the detailed description
This study uses TMS to temporarily disrupt neural activity in the left and right temporal cortex and examine the effect of this disruption on speech perception tasks. Vertex stimulation is included as a control condition against which left and right superior temporal stimulation effects are compared. Adult participants first undergo structural MRI and a speech localizer using functional MRI to identify speech-sensitive voxels in the left and right temporal cortex. These regions are set by-participant as the foci for stimulation. Stimulation site is blocked, and typically distributed across sessions. 10 Hz pulse trains of 2.5 sec each are delivered to the stimulation site, with an auditory stimulus arriving either immediately after the last pulse (Exps 2 and 6) or, for longer sentence level stimuli (Exp 3), during the pulse train. Behavioral measures include accuracy and reaction times to rate phonetic stimuli (Exp 2), detect the presence of a probe word in the preceding sentence (Exp 3), or categorize stimuli by phonetic contrast and talker (Exp 6).
- Conditions
- Neural Bases of Speech Perception
- Being tested
- Transcranial Magnetic Stimulation
- Keywords
- Speech perception, Left temporal lobe, Right temporal lobe
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Transcranial Magnetic StimulationDevice
TMS will be delivered in 10 Hz pulses for 2.5 seconds, with behavioral measures of speech perception and object categorization immediately following each pulse. TMS at this schedule is thought to temporarily disrupt activity at the stimulation site.
| Study group | Role | What they receive |
|---|---|---|
| Experiment 2. Phonetic precision disrupted by TMS | Experimental | 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. Receives: Device: Transcranial Magnetic Stimulation |
| Experiment 3. Phonetic ambiguity in continuous speech | Experimental | 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. Receives: Device: Transcranial Magnetic Stimulation |
| Experiment 6: Disruption of talker-specific phonetic learning using TMS. | Experimental | 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. Receives: Device: Transcranial Magnetic Stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Categorization accuracy
Participants categorize items which vary along a perceptual continuum. Steepness of the categorization curve is extracted to estimate categorization accuracy.
Measured: Immediately following the stimulation pulses (within one second of the final pulse).
Two-alternative forced choice accuracy
Participants are given two options and asked to indicate which item they heard in the previous signal. Accuracy in making this decision is a primary outcome measure.
Measured: Immediately following the stimulation pulses (within one second of the final pulse).
Two-alternative forced choice reaction time
Participants are given two options and asked to indicate which item they heard in the previous signal. Reaction time to make this decision is a primary outcome measure.
Measured: Immediately following the stimulation pulses (within one second of the final pulse).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Aug 2021
- Study start19 Dec 2024
- Primary completion31 Dec 2025 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Neural Bases of Speech PerceptionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Participants will receive blocks of stimulation at the left temporal lobe, right temporal lobe, and vertex, with the order of stimulation counterbalanced across participants (a crossover design). All analysis is within-subject. Participants in each arm will hear different types of speech stimuli, which allows for the assessment of the effect of stimulation at different stimulation sites on processing that specific aspect of the speech signal.
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 26 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Connecticut
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Deafness and Other Communication Disorders (NIDCD)
- Responsible party
- Principal investigator, Emily Myers, University of Connecticut
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04989309
- Sponsor's protocol ID
- H21-0046
- Other IDs
- R01DC013064
- Status last verified
- Dec 2024
- First submitted
- 6 Jul 2021
- Last updated
- 15 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Results of these studies will be used for teaching, research publications, and presentation at scientific meetings. De-identified raw data of all types (behavioral, MRI) will be available upon request after publication. MRI data will be processed ("skull stripped") to remove any identifiable anatomy before archival. We will archive data locally using Brain Imaging Data Structure (BIDS) naming conventions to facilitate data sharing. We plan to pre-register behavioral studies on the Open Science Framework (or similar platforms), and in the interests of scientific transparency, we will post de-identified behavioral data and analysis code on Open Science Framework or GitHub.
Publications
Kennedy-Higgins D, Devlin JT, Nuttall HE, Adank P. The Causal Role of Left and Right Superior Temporal Gyri in Speech Perception in Noise: A Transcranial Magnetic Stimulation Study. J Cogn Neurosci. 2020 Jun;32(6):1092-1103. doi: 10.1162/jocn_a_01521. Epub 2020 Jan 14.
PubMed 31933438Rossi S, Antal A, Bestmann S, Bikson M, Brewer C, Brockmoller J, Carpenter LL, Cincotta M, Chen R, Daskalakis JD, Di Lazzaro V, Fox MD, George MS, Gilbert D, Kimiskidis VK, Koch G, Ilmoniemi RJ, Lefaucheur JP, Leocani L, Lisanby SH, Miniussi C, Padberg F, Pascual-Leone A, Paulus W, Peterchev AV, Quartarone A, Rotenberg A, Rothwell J, Rossini PM, Santarnecchi E, Shafi MM, Siebner HR, Ugawa Y, Wassermann EM, Zangen A, Ziemann U, Hallett M; basis of this article began with a Consensus Statement from the IFCN Workshop on "Present, Future of TMS: Safety, Ethical Guidelines", Siena, October 17-20, 2018, updating through April 2020. Safety and recommendations for TMS use in healthy subjects and patient populations, with updates on training, ethical and regulatory issues: Expert Guidelines. Clin Neurophysiol. 2021 Jan;132(1):269-306. doi: 10.1016/j.clinph.2020.10.003. Epub 2020 Oct 24.
PubMed 33243615
Study at a glance
From the registry record, last updated by the sponsor on 15 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Frontal and Temporal Brain Areas in the Perception of Phonetic Category Structure
- ClinicalTrials.gov ID
- NCT04989309
- Acronym / sponsor ID
- H21-0046
- Conditions
- Neural Bases of Speech Perception
- Keywords
- Speech perception, Left temporal lobe, Right temporal lobe
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 26 participants (estimated)
- Lead sponsor
- University of ConnecticutUniversity, hospital or other
- Collaborators
- National Institute on Deafness and Other Communication Disorders (NIDCD)
- Study start
- 19 Dec 2024 (actual)
- Primary completion
- 31 Dec 2025 (estimated)
- Study completion
- 30 Jun 2026 (estimated)
- First posted
- 4 Aug 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This study uses TMS to temporarily disrupt neural activity in the left and right temporal cortex and examine the effect of this disruption on speech perception tasks. Vertex stimulation is included as a control condition against which left and right superior temporal stimulation effects are compared. Adult participants first undergo structural MRI and a speech localizer using functional MRI to identify speech-sensitive voxels in the left and right temporal cortex. These regions are set by-participant as the foci for stimulation. Stimulation site is blocked, and typically distributed across sessions. 10 Hz pulse trains of 2.5 sec each are delivered to the stimulation site, with an auditory stimulus arriving either immediately after the last pulse (Exps 2 and 6) or, for longer sentence level stimuli (Exp 3), during the pulse train. Behavioral measures include accuracy and reaction times to rate phonetic stimuli (Exp 2), detect the presence of a probe word in the preceding sentence (Exp 3), or categorize stimuli by phonetic contrast and talker (Exp 6).
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 3
- Model description
- Participants will receive blocks of stimulation at the left temporal lobe, right temporal lobe, and vertex, with the order of stimulation counterbalanced across participants (a crossover design). All analysis is within-subject. Participants in each arm will hear different types of speech stimuli, which allows for the assessment of the effect of stimulation at different stimulation sites on processing that specific aspect of the speech signal.
| Arm | Type | Receives |
|---|---|---|
| Experiment 2. Phonetic precision disrupted by TMS | Experimental | Device: Transcranial Magnetic StimulationExperiment 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. |
| Experiment 3. Phonetic ambiguity in continuous speech | Experimental | Device: Transcranial Magnetic StimulationExperiment 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. |
| Experiment 6: Disruption of talker-specific phonetic learning using TMS. | Experimental | Device: Transcranial Magnetic StimulationExperiment 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Monolingual native speaker of English
- No history of neurological impairments or disease
- Free of speech and language disorders (per self-report, and confirmed by short language battery described by Fidler, Vance, \& Plante, 2011)
- Pure-tone thresholds of 30 decibels or better in both ears (no worse than mild hearing loss), with no more than 15 dB between-ear difference.
- Right-handed, as confirmed by Oldfield Handedness Inventory
Key exclusion criteria (16 listed)
- Any condition where TMS would be contraindicated according to the most recent guidelines, including, but not limited to:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Transcranial Magnetic StimulationTMS will be delivered in 10 Hz pulses for 2.5 seconds, with behavioral measures of speech perception and object categorization immediately following each pulse. TMS at this schedule is thought to temporarily disrupt activity at the stimulation site. | Device | Experiment 2. Phonetic precision disrupted by TMS, Experiment 3. Phonetic ambiguity in continuous speech, Experiment 6: Disruption of talker-specific phonetic learning using TMS. |
Primary outcome
Categorization accuracy
Time frame: Immediately following the stimulation pulses (within one second of the final pulse).
Participants categorize items which vary along a perceptual continuum. Steepness of the categorization curve is extracted to estimate categorization accuracy.
Two-alternative forced choice accuracy
Time frame: Immediately following the stimulation pulses (within one second of the final pulse).
Participants are given two options and asked to indicate which item they heard in the previous signal. Accuracy in making this decision is a primary outcome measure.
Two-alternative forced choice reaction time
Time frame: Immediately following the stimulation pulses (within one second of the final pulse).
Participants are given two options and asked to indicate which item they heard in the previous signal. Reaction time to make this decision is a primary outcome measure.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Jun 2025.
- Background: PubMed 31933438Kennedy-Higgins D, Devlin JT, Nuttall HE, Adank P. The Causal Role of Left and Right Superior Temporal Gyri in Speech Perception in Noise: A Transcranial Magnetic Stimulation Study. J Cogn Neurosci. 2020 Jun;32(6):1092-1103. doi: 10.1162/jocn_a_01521. Epub 2020 Jan 14.
- Background: PubMed 33243615Rossi S, Antal A, Bestmann S, Bikson M, Brewer C, Brockmoller J, Carpenter LL, Cincotta M, Chen R, Daskalakis JD, Di Lazzaro V, Fox MD, George MS, Gilbert D, Kimiskidis VK, Koch G, Ilmoniemi RJ, Lefaucheur JP, Leocani L, Lisanby SH, Miniussi C, Padberg F, Pascual-Leone A, Paulus W, Peterchev AV, Quartarone A, Rotenberg A, Rothwell J, Rossini PM, Santarnecchi E, Shafi MM, Siebner HR, Ugawa Y, Wassermann EM, Zangen A, Ziemann U, Hallett M; basis of this article began with a Consensus Statement from the IFCN Workshop on "Present, Future of TMS: Safety, Ethical Guidelines", Siena, October 17-20, 2018, updating through April 2020. Safety and recommendations for TMS use in healthy subjects and patient populations, with updates on training, ethical and regulatory issues: Expert Guidelines. Clin Neurophysiol. 2021 Jan;132(1):269-306. doi: 10.1016/j.clinph.2020.10.003. Epub 2020 Oct 24.
- Individual participant dataSharing planned: Yes. Results of these studies will be used for teaching, research publications, and presentation at scientific meetings. De-identified raw data of all types (behavioral, MRI) will be available upon request after publication. MRI data will be processed ("skull stripped") to remove any identifiable anatomy before archival. We will archive data locally using Brain Imaging Data Structure (BIDS) naming conventions to facilitate data sharing. We plan to pre-register behavioral studies on the Open Science Framework (or similar platforms), and in the interests of scientific transparency, we will post de-identified behavioral data and analysis code on Open Science Framework or GitHub.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Transcranial Magnetic Stimulation in people with Neural Bases of Speech Perception, run by University of Connecticut at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: enrolling by invitation, as of the sponsor's last update on 15 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Categorization accuracy (time frame: Immediately following the stimulation pulses (within one second of the final pulse).). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04989309, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jun 2025.