Anodal tDCS Over Left PPC Enhances Visuospatial Attention and Alpha Power Among Young Adults
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.
調査の概要
研究の種類
入学 (実際)
段階
- 適用できない
連絡先と場所
研究場所
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İ̇stanbul
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Beykoz、İ̇stanbul、トルコ（Türkiye）、34820
- Istanbul Medipol University
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参加基準
適格基準
就学可能な年齢
- 大人
健康ボランティアの受け入れ
説明
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
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：基礎科学
- 割り当て：ランダム化
- 介入モデル：並列代入
- マスキング：独身
武器と介入
参加者グループ / アーム |
介入・治療 |
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実験的：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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偽コンパレータ：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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この研究は何を測定していますか？
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
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EEG recording and power in alpha band
時間枠：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
時間枠：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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協力者と研究者
スポンサー
捜査官
- スタディディレクター：Lütfü Hanoğlu, Professor、Medipol University
- スタディチェア：Mevhibe Sarıcaoğlu, PhD、Medipol University
- スタディディレクター：Miray Budak, PhD、Rutgers University-Newark
- スタディチェア：Fatma Aydın, MsC、Medipol University
研究記録日
主要日程の研究
研究開始 (実際)
一次修了 (実際)
研究の完了 (実際)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (実際)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
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