Language Development, Learning
Conditions
Keywords
transcranial electrical stimulation, tES, transcranial direct current stimulation, tDCS, second language acquisition, language learning, neuromodulation, healthy volunteers
Brief summary
This study investigates whether transcranial electrical stimulation (tES) delivered during structured language-learning sessions affects the rate and quality of second-language acquisition in adults. Adults who are learning or planning to learn a new language are randomly assigned in equal numbers to receive either active stimulation or sham (placebo) stimulation while completing structured language-learning content. Participants wear a non-invasive transcranial electrical stimulation headset that delivers a low-level electrical current through electrodes resting on the scalp, targeting cortical regions associated with language. Sessions typically last 20 to 30 minutes and may be completed at home or in person at a participating language program. Language proficiency is measured with a standardized assessment before and after the intervention period, with additional app-derived performance metrics and participant-reported measures collected throughout. A follow-up assessment may be conducted up to 12 months after the intervention ends to evaluate whether any observed effects persist. In this study the device is applied as a learning aid in healthy adults. It is not used to diagnose, treat, cure, or prevent any disease.
Detailed description
The study is a prospective, randomized, double-blind, sham-controlled investigation. Participants are randomized 1:1 to active or sham stimulation, with stratification by site or cohort as applicable. Neither participants nor the research team conducting outcome assessments are aware of assignment during data collection. Stimulation assignment is held by the Sub-Investigator and is not disclosed to the Principal Investigator until all outcome data are collected and locked and primary analyses are finalized. Sessions may be delivered by decentralized at-home administration, on-site administration at partner language programs and educational institutions, or a hybrid of the two. The protocol declares a bounded parameter envelope within which specific stimulation parameters, learning content, partner sites, and assessment instruments may be selected per cohort without protocol amendment. All parameters operate within the LOTES-2023 limited-output standard for transcranial electrical stimulation devices. For adult participants the declared envelope permits 0 to 4 mA average absolute current, a maximum current density of 2 mA/cm2 at the electrode contact area, and a maximum session duration of 60 minutes subject to a 6000 mC total-charge-per-session ceiling. Anticipated session durations are 20 to 30 minutes. Any modality within the transcranial electrical stimulation family may be used, including tDCS, tACS, tRNS, and tPCS. Intended cortical targets are the left perisylvian region and adjacent association cortex, including Broca's area and Wernicke's area. Montages use standard cephalic or extracephalic placements with at least one electrode positioned on the head. Because assessment instruments and specific stimulation parameters are selected per cohort within the declared envelope, each enrollment cohort has a cohort-specific Statistical Analysis Plan finalized and locked prior to unblinding of that cohort.
Interventions
Non-invasive transcranial electrical stimulation delivered by a scalp-mounted headset within the LOTES-2023 limited-output envelope, paired with structured language-learning content. Adult declared range 0 to 4 mA average absolute current, maximum current density 2 mA/cm2 at the electrode contact area, and maximum session duration 60 minutes subject to a 6000 mC per-session total charge limit. Electrodes are placed in standard cephalic or extracephalic montages targeting the left perisylvian region and adjacent association cortex.
Sham stimulation delivered by the same scalp-mounted headset, providing the initial cutaneous sensory experience of stimulation onset without sustained current delivery, paired with the same structured language-learning content. The specific validated sham approach is selected per cohort and documented in the corresponding cohort plan.
Sponsors
General Neuro Inc.
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
The Sub-Investigator holds the stimulation assignment and is not masked. Assignment is not disclosed to the Principal Investigator until all outcome data are collected and locked and primary analyses are finalized.
Intervention model description
Two parallel arms, active tES and sham tES, each paired with the same structured language-learning content. Participants are randomized 1:1, with stratification by site or cohort as applicable.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Adults aged 18 years or older * Able to understand the consent materials and the informed consent process in English, or in another language for which an IRB-approved consent form is available * Willing and able to participate in structured language-learning activities for the duration of the intervention period * Able to provide written informed consent
Exclusion criteria
* History of epilepsy or any seizure disorder * Active skin disease, open wounds, or significant skin irritation at electrode contact sites * Implanted electronic medical devices where stimulation would be contraindicated per device manufacturer guidance or investigator judgment after individual risk assessment * Significant cognitive impairment that would interfere with informed consent or study participation * Any other condition that, in the investigator's judgment, would compromise participant safety or the integrity of the study data
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline in Pearson PTE Express overall score | Baseline to end of intervention period, up to 8 weeks | Change in the overall score on the Pearson Test of English (PTE) Express, a computer-delivered, remotely proctored assessment of English language proficiency covering listening, reading, speaking, and writing. The overall score is reported on the Global Scale of English and ranges from 10 to 90, with higher scores indicating greater English proficiency. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of adverse events | Through the intervention period and follow-up, up to 12 months | Number and severity of adverse events reported, including tingling, itching or warmth under the electrodes, skin redness, headache, fatigue, difficulty sleeping, dizziness or lightheadedness, phosphenes, and skin irritation. |
Countries
United States
Contacts
CONTACTAlec Sheffield, PhD
CONTACTLuke Knoble
PRINCIPAL_INVESTIGATORAlec Sheffield, PhD
General Neuro Inc.
Outcome results
None listed