tDCS of the Left dlPFC: Effects on Information Processing

NCT ID: NCT07168031

Last Updated: 2025-09-11

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: NA
• Total Enrollment: 196 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-08-06
• Study Completion Date: 2027-08-31

Brief Summary

This study investigates how a non-invasive form of brain stimulation, called transcranial direct current stimulation (tDCS), affects brain activity and information processing in younger and older adults. The stimulation uses a very weak electrical current applied through electrodes placed on the scalp. This method is safe and widely used in research to study brain function.

Participants will complete computer-based tasks while receiving either active brain stimulation or a placebo (sham) stimulation. The task is designed to engage specific mental processes so that the investigators can study how the brain responds under different conditions. Brain activity will be measured using magnetic resonance imaging (MRI), both while participants perform the tasks and while they are resting.

The study will compare healthy younger (ages 20-40) and older (ages 60-80) adults to explore whether age influences how the brain responds to stimulation. By examining patterns of brain activation and connectivity, the investigators aim to better understand how tDCS can modulate cognitive processing across the adult lifespan.

The hypothesis is that applying tDCS to the left dorsolateral prefrontal cortex will change patterns of brain activity related to cognitive processing, and that these changes may differ between younger and older adults. This knowledge could help inform future research into brain stimulation techniques in different age groups.

Conditions

Healthy

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: DOUBLE

Study Groups

Active tDCS of the Left dlPFC

Participants receive active anodal tDCS over the left dorsolateral prefrontal cortex during an information processing task for 22 minutes at 1 mA, with a gradual ramp-up and ramp-down of 30 seconds at the beginning and end of the stimulation.

Group Type: EXPERIMENTAL

Active Transcranial Direct Current Stimulation (tDCS)

Intervention Type: DEVICE

High definition tDCS will be applied, using a Soterix Medical device and 4x1 ring electrodes. A centre ring electrode overlying the target cortical region (left dlPFC at position F3 according to the 10-20 system) will be surrounded by four return electrodes (position F1, FC3, F5, and AF3).

Sham tDCS of the Left dlPFC

Participants receive sham tDCS with the same setup and initial ramp-up of current to mimic the sensation of active stimulation. The current is turned off after the ramp-up period, and no further stimulation is delivered during the task.

Group Type: SHAM_COMPARATOR

Sham Transcranial Direct Current Stimulation (tDCS)

Intervention Type: DEVICE

The same setup and device as in the active tDCS group will be used, but in this case stimulation will be turned off after a ramp-up phase of 30 seconds. This mimics the same sensory feeling as active tDCS.

Interventions

Active Transcranial Direct Current Stimulation (tDCS)

High definition tDCS will be applied, using a Soterix Medical device and 4x1 ring electrodes. A centre ring electrode overlying the target cortical region (left dlPFC at position F3 according to the 10-20 system) will be surrounded by four return electrodes (position F1, FC3, F5, and AF3).

Intervention Type: DEVICE

Sham Transcranial Direct Current Stimulation (tDCS)

The same setup and device as in the active tDCS group will be used, but in this case stimulation will be turned off after a ramp-up phase of 30 seconds. This mimics the same sensory feeling as active tDCS.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Healthy younger adults (ages 20-40) or healthy older adults (ages 60-80)
• Normal or corrected-to-normal vision and hearing
• Right-handed (for consistency in brain stimulation)
• Able to give written informed consent and comply with study procedures

Exclusion Criteria

• History of neurological or psychiatric disorders
• Current use of medications that affect the central nervous system
• Metal implants, pacemakers, or other contraindications for MRI or tDCS
• History of seizures or epilepsy
• Pregnancy
• Participation in another brain stimulation study within the last 3 months
• Any condition judged by investigators to interfere with safe participation

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Bern

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Jessica Peter, Prof.

Role: PRINCIPAL_INVESTIGATOR

UniversityClinics, University of Bern

Locations

University of Bern, Department of Old Age Psychiatry and Psychotherapy

Bern, , Switzerland

Site Status: RECRUITING

Countries

Switzerland

Central Contacts

Sarah Godehardt

Role: CONTACT

sarah.godehardt@unibe.ch

+41 58 630 89 03

Facility Contacts

Jessica Peter, Prof.

Role: primary

jessica.peter@unibe.ch

+41 58 630 89 03

Other Identifiers

50012

Identifier Type: -

Identifier Source: org_study_id