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EpilepsyNCT05014841

The Neural Coding of Speech Across Human Languages

A study testing Speech Tasks in people with Epilepsy and Brain Tumor, run by University of California, San Francisco at 1 site in United States.

Enrolling by invitation

Enrolling by invitation. The study team selects and invites participants, usually from an existing group of patients.

Sites and contacts
Official record
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Trial summary

The overall goal of this study is to reveal the fundamental neural mechanisms that underlie comprehension across human spoken languages. An understanding of how speech is coded in the brain has significant implications for the development of new diagnostic and rehabilitative strategies for language disorders (e.g. Read more about this study

Who is it for?
Ages 18 to 70 years
Conditions the study is for
Epilepsy, Brain Tumor, Speech
What is being tested?
Speech Tasks
Could I receive a placebo?
No, everyone receives an active treatment
How many people
52 participants
Where
1 siteUnited States
Study dates
14 Sep 2015to 30 Aug 2027
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 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Participants with epilepsy or brain tumors at UCSF undergoing surgical electrode implantation for seizure localization or for speech and language mapping and
  • Participants with electrodes implanted in at least two regions of interest who are willing and able to cooperate with study tasks.

Who cannot join

  • Participants who lack capacity or decline to provide informed consent,
  • Participants who have significant cerebral lesions or
  • Participants with cognitive deficits that preclude reliable completion of study tasks.

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 California, San Francisco

    San Francisco, California, 94143

Other trials in United States

About this study

The overall goal of this study is to reveal the fundamental neural mechanisms that underlie comprehension across human spoken languages. An understanding of how speech is coded in the brain has significant implications for the development of new diagnostic and rehabilitative strategies for language disorders (e.g. aphasia, dyslexia, autism, et alia). The basic mechanisms underlying comprehension of spoken language are unknown. Researchers are only beginning to understand how the human brain extracts the most fundamental linguistic elements (consonants and vowels) from a complex and highly variable acoustic signal. Traditional theories have posited a 'universal' phonetic inventory shared by all humans, but this has been challenged by other newer theories that each language has its own unique and specialized code. An investigation of the cortical representation of speech sounds across languages can likely shed light on this fundamental question. Previous research has implicated the superior temporal cortex in the processing of speech sounds. Most of this work has been entirely carried out in English. The recording of neural activity directly from the cortical surface from individuals with different language experience is a promising approach since it can provide both high spatial and temporal resolution. This study will examine the mechanisms of phonetic encoding, by utilizing neurophysiological recordings obtained during neurosurgical procedures. High-density electrode arrays, advanced signal processing, and direct electrocortical stimulation will be utilized to unravel both local and population encoding of speech sounds in the lateral temporal cortex. This study will also examine the neural encoding of speech in patients who are monolingual and bilingual in Mandarin, Spanish, and English, the most common spoken languages worldwide, and feature important contrastive differences of pitch, formant, and temporal envelope. A cross-linguistic approach is critical for a true understanding of language, while also striving to achieve a broader approach of diversity and inclusion in neuroscience of language.

Read the detailed description

Experimental approaches with significantly greater spatial and temporal resolution are necessary to directly resolve, both local- and population- level, the contrastive encoding of speech sounds. This study proposes an innovative methodological approach using customized intracranial high-density electrode arrays to record neural activity directly from nonprimary auditory cortex in patients undergoing clinical neurosurgical procedures (acute intraoperative and chronic extraoperative). This approach overcomes obstacles in traditional neuroimaging by offering high signal-to-noise recordings, unprecedented detailed spatiotemporal resolution, and a large number of simultaneously recorded cortical sites in awake, behaving subjects. The research study team will leverage the diversity of languages spoken by patients that are treated at the large volume epilepsy and tumor brain mapping programs at the University of California, San Francisco. They will examine cortical responses to speech stimuli (natural speech corpora and control tokens) in Spanish, Mandarin, and English speakers (monolingual and bilingual). They will also focus on encoding models in three fundamental domains of acoustic-phonetic cues that are present in all languages: pitch, formants, and amplitude envelope. The aims of this study seeks to determine how pitch cues encode lexical tone processing in Mandarin (Aim 1), the cortical representation of vowels in Spanish and English (Aim 2), and the encoding of the speech amplitude envelope in Spanish and English (Aim 3). Together, these aims will elucidate mechanistic principles of speech encoding in the human auditory cortex to understand what is shared and different across human spoken languages. Abnormalities in these fundamental processes have been implicated in a host of communication disorders such as dyslexia, developmental language disorder, central hearing loss, and aphasia. These results should heavily impact current theories of speech processing and, therefore, will have significant implications for understanding and remediating human disorders across different languages.

Being tested
Speech Tasks
Medical subject headings
Epilepsy, Brain Neoplasms, Speech

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Speech TasksBehavioural

    Listen to 20-minutes of speech sounds in English, Spanish, and/or Mandarin.

Study groups in NCT05014841
Study groupRoleWhat they receive
Electrocorticography (ECoG) recording during Speech TasksExperimentalParticipants listened to 20-minute Speech Tasks while ECoG signals for neural activity was recorded during their intraoperative procedure or inpatient hospitalization at the University of California, San Francisco (UCSF).
Receives: Behavioral: Speech Tasks

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Number of Participants with Electrocorticography (ECoG) Signals for Neural Activity Identified During Intraoperative Procedure or Inpatient Hospitalization

    Number of participants with ECoG signals for neural activity identified during intraoperative procedure or inpatient hospitalization, between 10-30 minutes.

    Measured: Between 10-30 minutes

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Aug 2021
  2. Study start14 Sep 2015
  3. Primary completion31 Aug 2026 (estimated)
  4. Study completion30 Aug 2027 (estimated)

Resources

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
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
52 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05014841
Sponsor's protocol ID
U01NS117765
Other IDs
U01NS117765
Status last verified
Sep 2025
First submitted
13 Aug 2021
Last updated
16 Sep 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: No Individual Participant Data (IPD) will be made available to other researchers; only de-identified data will be shared with Collaborators for research analysis.

Questions about this trial

What is this clinical trial studying?

A study testing Speech Tasks in people with Epilepsy and Brain Tumor, run by University of California, San Francisco 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 2 inclusion and 3 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 16 Sep 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?

Number of Participants with Electrocorticography (ECoG) Signals for Neural Activity Identified During Intraoperative Procedure or Inpatient Hospitalization (time frame: Between 10-30 minutes). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 16 Sep 2025.

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