Decoding Mandarin speech features from brain-surface signals

Investigation of Chinese-Specific Speech Imagery Encoding and Decoding Using High-Density Electrocorticography

This project will try to decode imagined Mandarin speech, including lexical tones, from high-density brain-surface (ECoG) signals in adult patients who are having clinically indicated cortical electrode placement.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 50 (estimated)
• Ages: 20 Years to 80 Years
• Sex: All
• Sponsor: Second Affiliated Hospital, School of Medicine, Zhejiang University (other)
• Locations: 1 site (Hangzhou, Zhejiang)
• Trial ID: NCT07460037 on ClinicalTrials.gov

What this trial studies

Researchers will record high-density electrocorticography (ECoG) signals from adults who require temporary or permanent cortical electrodes as part of clinical neurosurgery. During recordings, participants will perform silent auditory speech imagery and other speech-related tasks while neural activity is captured. The team will develop and test decoding algorithms to reconstruct Mandarin speech features, with special focus on lexical tone, from the neural signals without overt articulation. Data will be collected intraoperatively and from implanted electrodes where clinically indicated and analyzed to determine how well tone-specific and other speech representations can be recovered.

Who should consider this trial

Good fit: Ideal candidates are adults (20–80) who are Mandarin speakers undergoing clinically indicated temporary or permanent high-density cortical electrode placement (for awake craniotomy for eloquent-area tumors or refractory epilepsy) and who can follow experimental tasks with largely preserved preoperative language function.

Not a fit: Patients who are not undergoing invasive cortical electrode placement, cannot cooperate with language or imagery tasks, have severe consciousness/emotional disorders, or are not Mandarin speakers are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this approach could help restore communication by translating imagined Mandarin speech, including tones, into usable outputs for people with severe speech impairment.

How similar studies have performed: Prior ECoG work in non-tonal languages has shown promising decoding of speech content and imagined speech, but direct decoding of Mandarin lexical tone from high-density ECoG is relatively novel and less well established.

Eligibility criteria

Inclusion Criteria:

* Age between 20 and 80 years.
* Ability and willingness to provide informed consent and comply with study procedures.
* No severe preoperative emotional or consciousness disorders that would preclude participation in experimental tasks.
* For patients undergoing intraoperative temporary high-density ECoG coverage: Patients with cerebral eloquent-area gliomas or refractory epilepsy undergoing awake craniotomy as part of standard clinical management.
* For patients undergoing intraoperative temporary high-density ECoG coverage: Lesions involving or adjacent to eloquent brain areas including language, motor, or memory-related regions.
* For patients undergoing intraoperative temporary high-density ECoG coverage: Mild mass effect without severe intracranial hypertension.
* For patients undergoing intraoperative temporary high-density ECoG coverage: Preoperative language function largely preserved, with naming, reading, and language comprehension ≥80% of normal performance.
* For patients undergoing permanent high-density ECoG implantation: Severe speech or language dysfunction caused by stroke, brain tumors, amyotrophic lateral sclerosis (ALS), or locked-in syndrome.
* For patients undergoing permanent high-density ECoG implantation: No substantial improvement after 3-6 months of adequate rehabilitation and disease duration \>12 months.
* For patients undergoing permanent high-density ECoG implantation: Structural integrity of speech imagery-related cortices (ventral central lobule, supramarginal gyrus, superior temporal gyrus, middle temporal gyrus, middle frontal gyrus, and inferior frontal gyrus).
* For patients undergoing permanent high-density ECoG implantation: Diagnosis of severe dysarthria or severe motor aphasia, with spontaneous speech score \<5/20 on the Aphasia Battery of Chinese (ABC) and auditory comprehension ≥80% of normal levels.

Exclusion Criteria:

* Significant mass effect with severe intracranial hypertension precluding awake craniotomy or electrode implantation.
* Severe neurological dysfunction that would prevent participation in study procedures (except for speech or language impairment in the permanent implantation cohort).
* Contraindications to MRI scanning or awake craniotomy, including incompatible implanted medical devices, severe claustrophobia, or obstructive sleep apnea syndrome.
* Severe psychiatric disorders or cognitive impairment preventing participation in treatment or follow-up assessments (Mini-Mental State Examination score \<24).
* Severe systemic medical comorbidities.
* Pregnancy or lactation.
* Refusal or inability to provide informed consent.

Where this trial is running

Hangzhou, Zhejiang

• The Second Affiliated Hospital, Zhejiang University School of Medicine — Hangzhou, Zhejiang, China (RECRUITING)

Study contacts

• Principal investigator: Feng Yan — Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University
• Study coordinator: Feng Yan, MD, PhD

Conditions: Aphasia, Dysarthria, ALS, Speech and Language Disorder, Stroke, Brain Tumor Adult, Epilepsies, locked-in Syndrome