NCT03814967Completed
Effects of Brain Stimulation on Higher-Order Cognition
Transcranial Direct Current Stimulation (tDCS) Studies of Behavioral and Electrophysiological (EEG) Correlates of Higher-Order Cognition
Source: ClinicalTrials.gov · Last updated 29 Jul 2025
Brief summary (registry, in English)
The purpose of this study is to better understand the neural correlates of higher-order cognition, both in the healthy brain and in schizophrenia, and to determine how these mechanisms are modulated by transcranial direct current stimulation (tDCS) at frontal and occipital scalp sites. Testing the effects of tDCS at these scalp sites on cognitive task performance will help us understand the roles of the brain regions corresponding to these sites during higher-order cognitive processing (language comprehension, cognitive control, and related attention and memory processes). Behavioral and electrophysiological (EEG) measures will be used to assess cognitive performance. The investigator's overarching hypothesis is that stimulating prefrontal circuits with tDCS can improve cognitive control performance, and ultimately performance on a range of cognitive tasks, as compared to stimulating a different cortical region (occipital cortex) or using sham stimulation. This study is solely intended as basic research in order to understand brain function in healthy individuals and individuals with schizophrenia. This study is not intended to diagnose, cure or treat schizophrenia or any other disease.
- Status (registry)
- Completed
- Study type
- Interventional
- Enrollment
- 86 (actual)
- First submitted
- 15 Jan 2019
- Start date
- 22 May 2019
- Primary completion date
- 31 May 2025
- Lead sponsor
- University of California, Davis
- Diseases
- Schizophrenia
- NCT number
- NCT03814967
What you commit to
- Study type: Interventional
- Participants enrolled: 86
- From 22 May 2019 to the primary completion date, 31 May 2025
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Metallic implants
Other illness
- Skin damage or skin conditions such as eczema at the sites where electrodes will be placed
- Epilepsy
- Any known history of neurological disorders (including epilepsy, amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), stroke, cerebral palsy, any DSM-5 axis I psychiatric disorder (for healthy control subjects), autism)
Other
- Pacemakers
- Implanted electrical (brain and spinal) stimulators
- Implanted defibrillator
- Hair styles hindering the placement of electrodes
- Cranial pathologies
- Head trauma
- Mental retardation
- Uncorrected vision problems that would hinder cognitive testing (this also pertains to subjects with color blindness in tasks where discriminating colored objects/items is necessary for successful performance)
- Pregnancy
- Substance dependence in the past six months
- Substance abuse in the past month
Who the study is looking for
- Participants must be able to sufficiently speak and understand English so as to be able to understand and complete cognitive tasks.
- All subjects must have the ability to give valid informed consent.
- Diagnosis of schizophrenia, schizophreniform or schizoaffective disorder
- No medication changes in the prior month
- No medication changes anticipated in the upcoming month
- Stable outpatient or partial hospital status
- Normal IQ (\>70; IQ will be measured by administering the Wechsler Abbreviated Scale of Intelligence (WASI) test)
Age in the registry: 18 years to 50 years · Sex: All · Accepts healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Imaging Research Center Coordinator of this site? Confirm its status | Sacramento | United States | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.