Anodal tDCS Over Left PPC Enhances Visuospatial Attention and Alpha Power Among Young Adults
3. juni 2026 oppdatert av: Halime Avunc, Medipol University
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.
Studieoversikt
Status
Fullført
Intervensjon / Behandling
Studietype
Intervensjonell
Registrering (Faktiske)
32
Fase
- Ikke aktuelt
Kontakter og plasseringer
Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.
Studiesteder
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İ̇stanbul
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Beykoz, İ̇stanbul, Tyrkia (Türkiye), 34820
- Istanbul Medipol University
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Deltakelseskriterier
Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
- Voksen
Tar imot friske frivillige
Ja
Beskrivelse
Inclusion Criteria:
- Age between 18 and 40 years
- Score of 21 or higher on the Montreal Cognitive Assessment Scale (MoCA)
Exclusion Criteria:
- 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
Studieplan
Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.
Hvordan er studiet utformet?
Designdetaljer
- Primært formål: Grunnvitenskap
- Tildeling: Randomisert
- Intervensjonsmodell: Parallell tildeling
- Masking: Enkelt
Våpen og intervensjoner
Deltakergruppe / Arm |
Intervensjon / Behandling |
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Eksperimentell: Anodal tDCS Group
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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.
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Sham-komparator: Sham tDCS Group
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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.
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Hva måler studien?
Primære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
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EEG recording and power in alpha band
Tidsramme: Before and immediately after applying tDCS
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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.
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Before and immediately after applying tDCS
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Cancellation Test
Tidsramme: Before and immediately after applying tDCS
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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.
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Before and immediately after applying tDCS
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Samarbeidspartnere og etterforskere
Det er her du vil finne personer og organisasjoner som er involvert i denne studien.
Sponsor
Etterforskere
- Studieleder: Lütfü Hanoğlu, Professor, Medipol University
- Studiestol: Mevhibe Sarıcaoğlu, PhD, Medipol University
- Studieleder: Miray Budak, PhD, Rutgers University-Newark
- Studiestol: Fatma Aydın, MsC, Medipol University
Studierekorddatoer
Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.
Studer hoveddatoer
Studiestart (Faktiske)
1. februar 2021
Primær fullføring (Faktiske)
1. juli 2021
Studiet fullført (Faktiske)
1. november 2021
Datoer for studieregistrering
Først innsendt
22. mai 2026
Først innsendt som oppfylte QC-kriteriene
3. juni 2026
Først lagt ut (Faktiske)
4. juni 2026
Oppdateringer av studieposter
Sist oppdatering lagt ut (Faktiske)
4. juni 2026
Siste oppdatering sendt inn som oppfylte QC-kriteriene
3. juni 2026
Sist bekreftet
1. mai 2026
Mer informasjon
Begreper knyttet til denne studien
Ytterligere relevante MeSH-vilkår
Andre studie-ID-numre
- E-10840098-772.02-605
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