The Neural Coding of Speech Across Human Languages

NCT05014841 | Enrolling By Invitation

• 1 other identifier: U01NS117765
• Study Type: interventional
• Target: 52
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Epilepsy; Brain Tumor; Speech; Bilingualism

Outcome Measures

Primary Outcomes (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.

  Between 10-30 minutes

Study Arms (1)

Electrocorticography (ECoG) recording during Speech Tasks

EXPERIMENTAL

Participants 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).

Behavioral: Speech Tasks

Interventions

Speech Tasks BEHAVIORAL

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

Electrocorticography (ECoG) recording during Speech Tasks

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• University of California, San Francisco: lead
• University of California, Berkeley: collaborator
• Lawrence Livermore National Laboratory: collaborator
• The University of Hong Kong: collaborator
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (1)

University of California, San Francisco

San Francisco, California, 94143, United States

Location

MeSH Terms

Conditions

Epilepsy; Brain Neoplasms; Speech

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Central Nervous System Neoplasms; Nervous System Neoplasms; Neoplasms by Site; Neoplasms; Verbal Behavior; Communication; Behavior

Study Officials

• Edward F Chang, MD

  University of California, San Francisco

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 13, 2021
• First Posted: August 20, 2021
• Study Start: September 14, 2015
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 30, 2027
• Last Updated: September 16, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)