Left and Right Hemisphere Contributions to Speech Perception

NCT04989309 | Enrolling By Invitation

• 2 other identifiers: H21-0046R01DC013064
• Study Type: interventional
• Target: 26
• Locations: 1 country
• Sites: 1

Brief 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 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.

Conditions

Neural Bases of Speech Perception

Keywords

Speech perception; Left temporal lobe; Right temporal lobe

Outcome Measures

Primary Outcomes (3)

• Categorization accuracy

  Participants categorize items which vary along a perceptual continuum. Steepness of the categorization curve is extracted to estimate categorization accuracy.

  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.

  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.

  Immediately following the stimulation pulses (within one second of the final pulse).

Study Arms (3)

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.

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.

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.

Device: Transcranial Magnetic Stimulation

Interventions

Transcranial Magnetic Stimulation DEVICE

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.

Experiment 2. Phonetic precision disrupted by TMS; Experiment 3. Phonetic ambiguity in continuous speech; Experiment 6: Disruption of talker-specific phonetic learning using TMS.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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

You may not qualify if:

• 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
• Antidepressants including Imipramine, amitriptyline, sertraline, venlafaxine, buproprion
• Antipsychotics including Chlorpromazine, clozapine, haloperidol, aripiprazole
• 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

Sponsors & Collaborators

• University of Connecticut: lead
• National Institute on Deafness and Other Communication Disorders (NIDCD): collaborator

Study Sites (1)

University of Connecticut

Storrs, Connecticut, 06268, United States

Location

Related Publications (2)

• 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.

  PMID: 31933438 BACKGROUND

• Rossi 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.

  PMID: 33243615 BACKGROUND

MeSH Terms

Interventions

Transcranial Magnetic Stimulation

Intervention Hierarchy (Ancestors)

Magnetic Field Therapy; Therapeutics

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants will receive stimulation at different sites (left and right temporal areas, vertex control), and may be aware of the location of placement of the TMS coil, so in a strict sense participants cannot be fully unaware of the stimulation site.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Model Details: 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.

Study Record Dates

• First Submitted: July 6, 2021
• First Posted: August 4, 2021
• Study Start: December 19, 2024
• Primary Completion: December 31, 2025
• Study Completion (Estimated): June 30, 2026
• Last Updated: June 15, 2025

Record last verified: 2024-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: SAP, ANALYTIC CODE
• Time Frame: We will share data and code upon publication, and de-identified data will be available indefinitely.
• Access Criteria: Open

Locations

US (1)