Precision HD-tACS for Enhancing Sensory Experience in Schizophrenia (TherACles)
Precision HD-tACS-Based Therapy for the Qualitative and Phenomenological Enhancement of Sensory Experiences in Schizophrenia
To ensure unified sensory perception, the brain must link information from different senses across time and space. This unification of perception often referred to as a perceptual "binding constraint" is a prerequisite for any organized perception. Patients with schizophrenia exhibit deficits in the spatiotemporal binding of sensory information . Electroencephalography (EEG) studies highlight the role of delta-theta oscillatory dynamics (2-8 Hz) in neuronal entrainment processes underlying spatiotemporal binding, which enables the formation of a coherent and organized perceptual representation . These same dynamics are disrupted in schizophrenia .
In tasks assessing perceptual binding, such alterations manifest as widened temporal binding windows, reflecting impaired temporal structuring of visual events. Physiologically, these disruptions may stem from impaired feedback mechanisms within the cortico-cerebello-thalamo-cortical (CCTC) loop. Schizophrenia patients also exhibit functional and structural deficits in the pulvinar and frontal cortex, key nodes of the CCTC loop .
Recent technical advances in transcranial neurostimulation have reinforced its potential as a therapeutic tool. High-definition transcranial alternating current stimulation (HD-tACS) now enables individualized modulation of pre-identified neural networks , including targeted interventions for schizophrenia . Based on a personalized stimulation protocol, this research project proposes precision HD-tACS therapy, tailored for each patient according to their delta-theta peak frequency measured via EEG and the optimal functional stimulation site identified with functional MRI (fMRI). Stimulation will be applied functionally, i.e., while the patient performs a cognitive task.
Structural connectivity alterations have been observed in fronto-thalamic, thalamo-cingulate, and cortico-cerebellar pathways in schizophrenia, potentially underpinning temporal and spatial binding deficits. Assessing the integrity of the CCTC loop with diffusion tensor imaging (DTI) will allow quantification of fiber coherence and white matter density connecting cortical and subcortical regions within this network.To evaluate both baseline perceptual deficits and the potential improvements induced by stimulation, a control group of healthy participants will be included.
調査の概要
状態
研究の種類
入学 (推定)
段階
- 適用できない
連絡先と場所
研究連絡先
- 名前:Lydie SARTELET
- 電話番号:+334 37 91 55 31
- メール:lydie.sartelet@ch-le-vinatier.fr
参加基準
適格基準
就学可能な年齢
- 大人
- 高齢者
健康ボランティアの受け入れ
説明
Inclusion Criteria for control group and patient:
- Be aged 18 to 65 years inclusive.
- Have read and understood the study information sheet.
- Be affiliated with a social security system or be a beneficiary.
- Have normal or corrected-to-normal vision (glasses or contact lenses).
Exclusion Criteria for control group :
- Any contraindication to tACS, e.g., cardiac pacemaker or other devices that could interfere with the electric field.
- Any contraindication to MRI, e.g., neurological stimulator, pacemaker, cardiac defibrillator, cardiac or vascular prosthesis, intracranial clips or clamps, cerebrospinal fluid shunt, metallic fragments in the eyes, cochlear implants, severe claustrophobia. (A standardized MRI screening questionnaire will be provided.)
- Pregnancy or breastfeeding. (Pregnancy status will be verified with a test on the day of the exam.)
- Legal incapacity (under guardianship, conservatorship, or judicial/administrative detention) or inability to provide informed consent.
- Major psychiatric disorders (excluding tobacco use disorder).
- Neurological disorders.
- Severe somatic disorders that could interfere with participation.
- Uncorrected visual impairments.
- Recent consumption of substances likely to alter brain activity (alcohol, drugs, etc.).
- Presence of any psychiatric disorder.
- Under legal protection (guardianship or conservatorship).
Exclusion Criteria - Patient Group
A potential patient participant will be excluded if they have:
- Any contraindication to tACS, e.g., cardiac pacemaker or other devices that could interfere with the electric field.
- Any contraindication to MRI, e.g., neurological stimulator, pacemaker, cardiac defibrillator, cardiac or vascular prosthesis, intracranial clips or clamps, cerebrospinal fluid shunt, metallic fragments in the eyes, cochlear implants, severe claustrophobia. (A standardized MRI screening questionnaire will be provided.)
- Pregnancy or breastfeeding. (Pregnancy status will be verified with a test on the day of the exam.)
- Legal incapacity (under guardianship, conservatorship, or judicial/administrative detention) or inability to provide informed consent.
- Major psychiatric disorders other than schizophrenia (excluding tobacco use disorder).
- Neurological disorders.
- Severe somatic disorders that could interfere with participation.
- Uncorrected visual impairments.
- Recent consumption of substances likely to alter brain activity (alcohol, drugs, etc.).
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:ダブル
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
|
アクティブコンパレータ:Control Group Theta active
|
Active HD-tACS
|
|
偽コンパレータ:Control Group Sham
|
Sham HD-tACS
|
|
アクティブコンパレータ:Schizophrenic patients Group Theta active
|
Active HD-tACS
|
|
偽コンパレータ:Schizophrenic patients Group Sham
|
Sham HD-tACS
|
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 |
|---|---|---|
|
Point of subjective equality(PSE)
時間枠:Day1: pre-intervention From 2 days to 20 days maximum: intervention and post-intervention
|
This outcome measures perceptual bias by estimating the Point of Subjective Equality (PSE), defined as the stimulus intensity at which participants perceive two stimuli as equal with 50% probability.
The PSE is extracted from a fitted psychometric function and compared between PRE and POST phases.
Unit: same as stimulus dimension (e.g., ms, Hz, or intensity level).
No fixed min/max value
|
Day1: pre-intervention From 2 days to 20 days maximum: intervention and post-intervention
|
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Functional connectivity, assessed via the phase-locking value (PLV).
時間枠:Day1: pre-intervention From 2 days to 20 days maximum: post-intervention
|
Electrophysiological data analysis will focus on signal coherence, measured by the phase-locking value (PLV).
The PLV quantifies over time the phase-locking differences (Δφ) between different topographical points.
When EEG activity is entrained by an external stimulation, signal coherence increases, and Δφ remains consistent across trials.
Conversely, if there is no relationship between the signals recorded at different scalp locations, Δφ will vary randomly across trials.
Δφ values will be compared between the PRE and POST stimulation phases.
Index between 0 and 1
|
Day1: pre-intervention From 2 days to 20 days maximum: post-intervention
|
協力者と研究者
スポンサー
捜査官
- 主任研究者:William VALLET, PhD、Le Vinatier Psychiatrie Universitaire Lyon Métropole
研究記録日
主要日程の研究
研究開始 (推定)
一次修了 (推定)
研究の完了 (推定)
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
本研究に関する用語
キーワード
その他の研究ID番号
- 2025-A02370-49
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