Intensity-Dependent Effects of 4-week Transcranial Direct Current Stimulation on Motor Learning in Healthy Young Adults

NCT ID: NCT07089069

Last Updated: 2025-07-28

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 44 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-07-20
• Study Completion Date: 2025-10-01

Brief Summary

The goal of this clinical trial is to investigate the effects of different intensities of transcranial direct current stimulationover primary motor cortex on motor learning in healthy adults. The main question it aims to answer is:

Which intensity of tDCS can best improve motor learning? Researchers will compare 1 mA, 2 mA, and 3 mA tDCS to sham tDCS to see which intensity of tDCS is most effective in improving the ability of motor learning.

Participants will be randomly divided into four groups and receive 4 different intensities of tDCS(1 mA, 2 mA, 3 mA and sham tDCS),and will be blinded to the type of tDCS they received. We hypothesized that anodal tDCS at 2 mA would produce the most substantial improvement in motor learning.

Detailed Description

The present study aimed to investigate the effects of different intensities of tDCS-specifically 1 mA, 2 mA, and 3 mA-on motor learning in healthy adults. Both the acute effects following a single tDCS session and the cumulative effects after a 4-week intervention (10 sessions) were evaluated. Additionally, the study aimed to determine whether improvements in motor learning induced by 4 weeks of repeated tDCS would be sustained one week after completion of the intervention. We hypothesized that anodal tDCS at 2 mA would produce the most substantial improvement in motor sequence learning, both following a single session and after a 4-week intervention, compared to 1 mA, 3 mA, and sham stimulation. Furthermore, we expected that the motor learning gains observed in the 2 mA group would be sustained one week post-intervention, indicating the persistence of tDCS-induced effects. In contrast, we anticipated minimal improvement in the 1 mA group due to insufficient stimulation intensity, and no additional or even reduced benefits in the 3 mA group compared to the 2 mA group.

Conditions

Transcranial Direct Current Stimulation (tDCS)

Study Design

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

Study Groups

1 mA transcranial direct current stimulation

The participants will receive 1 mA transcranial direct current stimulation (tDCS) over primary motor cortex(M1) intervention for a period of four weeks (10 sessions), but the participants will be blinded of what kind of intervention they are receiving.

Group Type: EXPERIMENTAL

1 mA transcranial direct current stimulation

Intervention Type: DEVICE

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The stimulation intensity will be set at 1 mA. The stimulation will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

2 mA transcranial direct current stimulation group

The participants will receive 2 mA transcranial direct current stimulation (tDCS) over primary motor cortex(M1) intervention for a period of four weeks (10 sessions), but the participants will be blinded of what kind of intervention they are receiving.

Group Type: EXPERIMENTAL

2 mA transcranial direct current stimulation

Intervention Type: DEVICE

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The stimulation intensity will be set at 2 mA. The stimulation will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

3 mA transcranial direct current stimulation group

The participants will receive 3 mA transcranial direct current stimulation (tDCS) over primary motor cortex(M1) intervention for a period of four weeks (10 sessions), but the participants will be blinded of what kind of intervention they are receiving.

Group Type: EXPERIMENTAL

3 mA transcranial direct current stimulation

Intervention Type: DEVICE

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The stimulation intensity will be set at 3 mA. The stimulation will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

sham transcranial direct current stimulation group

The participants will receive sham transcranial direct current stimulation (tDCS) over primary motor cortex(M1) intervention for a period of four weeks (10 sessions), but the participants will be blinded of what kind of intervention they are receiving.

Group Type: SHAM_COMPARATOR

sham transcranial direct current stimulation

Intervention Type: DEVICE

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The intervention will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation，but there is not current in between. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

Interventions

3 mA transcranial direct current stimulation

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The stimulation intensity will be set at 3 mA. The stimulation will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

Intervention Type: DEVICE

2 mA transcranial direct current stimulation

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The stimulation intensity will be set at 2 mA. The stimulation will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

Intervention Type: DEVICE

1 mA transcranial direct current stimulation

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The stimulation intensity will be set at 1 mA. The stimulation will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

Intervention Type: DEVICE

sham transcranial direct current stimulation

The intervention will be conducted using a battery-powered stimulator (TCS-E2000, Shenzhen Yingchi Technology Co., Ltd) through a pair of saline-soaked sponge electrodes (5 cm × 7 cm).The intervention will last for 20 minutes each time, with a 10 s fade-in period at the start and a 10-s fade-out period at the end of stimulation，but there is not current in between. The participants will receive intervention lasting for four weeks(10 sessions).The anodal electrode will be placed over the primary motor cortex (M1), and the reference electrode will be positioned at the center of the forehead.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

1. age between 18 and 25 years; (2) normal or corrected-to-normal vision; (3) no history of pregnancy, cardiovascular disease, other physical impairments or illnesses, and no personal or family history of mental illness; (4) no implantation of any internal or external medical devices; and (5) right-handedness.

Exclusion Criteria

-

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 25 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Beijing Sport University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Other Identifiers

2025044H

Identifier Type: -

Identifier Source: org_study_id