tDCSNCT07625566
Anodal tDCS Over Left PPC Enhances Visuospatial Attention and Alpha Power Among Young Adults
A study testing Anodal tDCS in people with tDCS and Posterior Parietal Cortex, run by Medipol University at 1 site in Turkey (Türkiye).
Trial summary
Background: Visuospatial attention enables individuals to detect and process relevant stimuli efficiently. The posterior parietal cortex (PPC), a core hub of the dorsal attention network, exerts top-down control over visual scanning and is closely linked to alpha-band oscillations (8-13 Hz), which index attentional… Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- tDCS, Posterior Parietal Cortex, Visual Attention
- What is being tested?
- Anodal tDCS
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 32 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Feb 2021to 1 Nov 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age between 18 and 40 years
- Score of 21 or higher on the Montreal Cognitive Assessment Scale (MoCA)
Who cannot join
- History of neurological or psychiatric illness
- Uncorrected visual impairments
- MoCA score of 21 or lower
- Use of medications affecting cortical excitability
- History of seizures or epilepsy
- Presence of intracranial metal objects, implanted stimulating devices, or pacemakers
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul Medipol University
Beykoz, İ̇stanbul, 34820
About this study
Background: Visuospatial attention enables individuals to detect and process relevant stimuli efficiently. The posterior parietal cortex (PPC), a core hub of the dorsal attention network, exerts top-down control over visual scanning and is closely linked to alpha-band oscillations (8-13 Hz), which index attentional allocation and inhibition of distractors. Transcranial direct current stimulation (tDCS) offers a noninvasive method to alter cortical excitability transiently, but evidence for its effects on PPC-mediated attention and alpha power remains mixed.
Objective: This randomized, single-blind trial examined whether anodal tDCS over the left PPC modulates visuospatial attention and resting-state alpha power in young adults, and whether EEG changes predict behavioral performance.
Method: Thirty-two healthy participants (18-40 years) were randomized to anodal (2 mA, 20 min; n=15) or sham (n=17) stimulation. Cancellation Test performance and resting-state EEG were assessed pre- and post-stimulation. EEG analyses focused on artifact-free alpha power; regression models probed associations between neural and behavioral changes.
- Conditions
- tDCS, Posterior Parietal Cortex, Visual Attention, EEG
- Being tested
- Anodal tDCS, Sham tDCS
- Keywords
- tDCS, posterior parietal cortex, visuospatial attention, EEG alpha oscillations
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Anodal tDCSDevice
Anodal tDCS Protocol: In the Anodal tDCS participant group, a direct current of 2 mA was applied for 20 minutes in accordance with the safety guidelines. To provide cortical stimulation, the superficial anodal electrode of the device was placed on the P3 region (left PPC), which is located in the left superior parietal lobe, corresponds to Brodmann area (BA) 40, and is associated with the dorsal visual pathway according to the international 10-20 EEG system. The reference electrode was placed on the contralateral (opposite) shoulder.
Sham tDCSDevice
Sham tDCS Protocol: The anode superficial electrode of the device was placed on the P3 region (left PPC), located in the left superior parietal lobe, corresponding to Brodmann area (BA) 40, and associated with the dorsal visual pathway according to the international 10-20 EEG system. The reference electrode was placed on the contralateral (opposite) shoulder. In the Sham tDCS group, a single 20-minute sham session was administered over the left posterior parietal cortex (P3) without delivering current, in accordance with the safety guidelines.
| Study group | Role | What they receive |
|---|---|---|
| Anodal tDCS Group | Experimental | Not described Receives: Device: Anodal tDCS |
| Sham tDCS Group | Sham comparator | Not described Receives: Device: Sham tDCS |
What is being measured
The primary outcome is the main question the study is designed to answer.
EEG recording and power in alpha band
EEG recordings were acquired in a semi-dark, electrically shielded Faraday room using a BrainAmp 32-Channel DC System (Brain Products, Munich, Germany). Signals were sampled at 500 Hz with a 0.01-250 Hz bandpass filter and recorded using BrainVision Recorder software. A 32-channel Ag/AgCl electrode cap (Easycap) was positioned according to the international 10-20 system. Resting-state EEG data were collected for 4 minutes with eyes open and 4 minutes with eyes closed. Numerical evaluation of artifact-free EEG data for power density calculation is performed using Fast Fourier Transform (FFT) with 0.5 Hz frequency resolution, and alpha (8-13 Hz) bands were calculated and then averaged over these power spectrum values. The amplitude values, measured from peak to peak, were recorded for each individual, and the necessary data for statistical analysis were collected.
Measured: Before and immediately after applying tDCS
Cancellation Test
The Cancellation Test is one of the most widely used tools for assessing visuospatial attention. IT consists of four subtests arranged on A4-sized sheets. Each subtest includes 60 target stimuli distributed among 300 total stimuli. For each subtest, separate scores are calculated for the right and left sides, including the number of correctly marked targets (IT1), omitted targets (IT2), incorrectly marked letters/shapes (IT3), total error score (IT4), and scanning time (IT5). The total error score is calculated as the sum of omitted targets and incorrectly marked letters/shapes. Achieving a high score (i.e., a high number of correctly marked targets and a low number of errors) and a short completion time (time score) indicate better performance. İn the present study, the paper-and-pencil version of the Cancellation Test was chosen to reliably assess visuospatial attention and subtle tDCS-induced changes.
Measured: Before and immediately after applying tDCS
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jun 2026
- Study start1 Feb 2021
- Primary completion1 Jul 2021
- Study completion1 Nov 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for tDCSStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medipol University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Halime Avunc, Medipol University
- Investigators
- Mevhibe Sarıcaoğlu, PhD, Study chair, Medipol UniversityMiray Budak, PhD, Study director, Rutgers University-NewarkFatma Aydın, MsC, Study chair, Medipol UniversityLütfü Hanoğlu, Professor, Study director, Medipol University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07625566
- Sponsor's protocol ID
- E-10840098-772.02-605
- Status last verified
- May 2026
- First submitted
- 22 May 2026
- Last updated
- 4 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Anodal tDCS Over Left PPC Enhances Visuospatial Attention and Alpha Power Among Young Adults
- ClinicalTrials.gov ID
- NCT07625566
- Acronym / sponsor ID
- E-10840098-772.02-605
- Conditions
- tDCS, Posterior Parietal Cortex, Visual Attention, EEG
- Keywords
- tDCS, posterior parietal cortex, visuospatial attention, EEG alpha oscillations
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Medipol UniversityUniversity, hospital or other
- Study start
- 1 Feb 2021 (actual)
- Primary completion
- 1 Jul 2021 (actual)
- Study completion
- 1 Nov 2021 (actual)
- First posted
- 4 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background: Visuospatial attention enables individuals to detect and process relevant stimuli efficiently. The posterior parietal cortex (PPC), a core hub of the dorsal attention network, exerts top-down control over visual scanning and is closely linked to alpha-band oscillations (8-13 Hz), which index attentional allocation and inhibition of distractors. Transcranial direct current stimulation (tDCS) offers a noninvasive method to alter cortical excitability transiently, but evidence for its effects on PPC-mediated attention and alpha power remains mixed.
Objective: This randomized, single-blind trial examined whether anodal tDCS over the left PPC modulates visuospatial attention and resting-state alpha power in young adults, and whether EEG changes predict behavioral performance.
Method: Thirty-two healthy participants (18-40 years) were randomized to anodal (2 mA, 20 min; n=15) or sham (n=17) stimulation. Cancellation Test performance and resting-state EEG were assessed pre- and post-stimulation. EEG analyses focused on artifact-free alpha power; regression models probed associations between neural and behavioral changes.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Anodal tDCS Group | Experimental | Device: Anodal tDCS |
| Sham tDCS Group | Sham comparator | Device: Sham tDCS |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Age between 18 and 40 years
- Score of 21 or higher on the Montreal Cognitive Assessment Scale (MoCA)
Key exclusion criteria (6 listed)
- History of neurological or psychiatric illness
- Uncorrected visual impairments
- MoCA score of 21 or lower
- Use of medications affecting cortical excitability
- History of seizures or epilepsy
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Anodal tDCSAnodal tDCS Protocol: In the Anodal tDCS participant group, a direct current of 2 mA was applied for 20 minutes in accordance with the safety guidelines. To provide cortical stimulation, the superficial anodal electrode of the device was placed on the P3 region (left PPC), which is located in the left superior parietal lobe, corresponds to Brodmann area (BA) 40, and is associated with the dorsal visual pathway according to the international 10-20 EEG system. The reference electrode was placed on the contralateral (opposite) shoulder. | Device | Anodal tDCS Group |
| Sham tDCSSham tDCS Protocol: The anode superficial electrode of the device was placed on the P3 region (left PPC), located in the left superior parietal lobe, corresponding to Brodmann area (BA) 40, and associated with the dorsal visual pathway according to the international 10-20 EEG system. The reference electrode was placed on the contralateral (opposite) shoulder. In the Sham tDCS group, a single 20-minute sham session was administered over the left posterior parietal cortex (P3) without delivering current, in accordance with the safety guidelines. | Device | Sham tDCS Group |
Primary outcome
EEG recording and power in alpha band
Time frame: Before and immediately after applying tDCS
EEG recordings were acquired in a semi-dark, electrically shielded Faraday room using a BrainAmp 32-Channel DC System (Brain Products, Munich, Germany). Signals were sampled at 500 Hz with a 0.01-250 Hz bandpass filter and recorded using BrainVision Recorder software. A 32-channel Ag/AgCl electrode cap (Easycap) was positioned according to the international 10-20 system. Resting-state EEG data were collected for 4 minutes with eyes open and 4 minutes with eyes closed. Numerical evaluation of artifact-free EEG data for power density calculation is performed using Fast Fourier Transform (FFT) with 0.5 Hz frequency resolution, and alpha (8-13 Hz) bands were calculated and then averaged over these power spectrum values. The amplitude values, measured from peak to peak, were recorded for each individual, and the necessary data for statistical analysis were collected.
Cancellation Test
Time frame: Before and immediately after applying tDCS
The Cancellation Test is one of the most widely used tools for assessing visuospatial attention. IT consists of four subtests arranged on A4-sized sheets. Each subtest includes 60 target stimuli distributed among 300 total stimuli. For each subtest, separate scores are calculated for the right and left sides, including the number of correctly marked targets (IT1), omitted targets (IT2), incorrectly marked letters/shapes (IT3), total error score (IT4), and scanning time (IT5). The total error score is calculated as the sum of omitted targets and incorrectly marked letters/shapes. Achieving a high score (i.e., a high number of correctly marked targets and a low number of errors) and a short completion time (time score) indicate better performance. İn the present study, the paper-and-pencil version of the Cancellation Test was chosen to reliably assess visuospatial attention and subtle tDCS-induced changes.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jun 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mevhibe Sarıcaoğlu, PhD study chair
Medipol University
Miray Budak, PhD study director
Rutgers University-Newark
Fatma Aydın, MsC study chair
Medipol University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Anodal tDCS in people with tDCS and Posterior Parietal Cortex, run by Medipol University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
EEG recording and power in alpha band (time frame: Before and immediately after applying tDCS). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Jun 2026.