About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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
Disqualifiers
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
Trial design
Parallel
Treatments tested in this trial
Active transcranial electrical stimulation (tES)
DeviceNon-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 transcranial electrical stimulation (tES)
DeviceSham 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.
Treatment groups
Trial outcomes
Primary outcomes
Change from baseline in Pearson PTE Express overall score
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 outcomes
Incidence of adverse events
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.
Sponsors and contacts
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