Induction and Stabilization of Gamma Oscillations With 40 Hz Transcranial Alternating Current Stimulation in Healthy Elderly
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Working Memory behavioral performance
研究概览
简要总结
This study aims to compare the efficacy of different 40 Hz tACS protocols in entraining gamma oscillations, which are linked to various cognitive functions and play a significant role in cognitive impairments like Alzheimer's disease. Specifically, it examines the effects of 40 Hz tACS applied to frontal brain regions versus fronto-temporal regions on gamma oscillations and working memory in healthy elderly individuals.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Outcomes Assessor)
入排标准
- 年龄范围
- 50 Years 至 85 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •healthy elderly between 50-80 years of age
- •normal or corrected to normal eye vision
- •right-handed
- •non-smokers
- •at least 70 % accuracy in working memory training task
排除标准
- •history of neurological or psychiatric disorders including seizures or epilepsy,
- •Taking CNS, blood pressure and other medications
- •having metal implants in the head and neck
- •significant cognitive decline meassured by The Montreal Cognitive Assessment (MoCA)
研究组 & 干预措施
40 Hz prefrontal Transcranial alternating current stimulation
During prefrontal tACS, an alternating electrical current with a 1 milliamp peak-to-peak amplitude will be delivered, featuring a 15-second ramp-up at the start and a 15-second ramp-down at the end. The stimulation duration is 20 minutes and four channels are used for delivering sinusoidal alternating currents to the head. The alternating current was delivered to the prefrontal cortex bilaterally with the electrodes at F3 and F4 and the return electrodes were placed at the ipsilateral mastoids at TP9 and TP10 (international 10-20 EEG electrode placement system).
干预措施: Transcranial alternating current stimulation (Device)
40 Hz frontal-temporal Transcranial alternating current stimulation
During frontal-temporal tACS, an alternating electrical current with a personalized peak-to-peak stimulation intensity will be delivered, featuring a 15-second ramp-up at the start and a 15-second ramp-down at the end. The stimulation duration is 20 minutes and four channels are used for delivering sinusoidal alternating currents to the head. The alternating current was delivered to the prefrontal and temporal cortices with the active electrodes at AF3-T7 and the return electrodes over AF4-T8 (according international 10-20 EEG electrode placement system).
干预措施: Transcranial alternating current stimulation (Device)
sham Transcranial alternating current stimulation
During sham tACS, an alternating artificial electrical current will be delivered, only ramping the current for 15 seconds up and 15 seconds down at the beginning and end of the stimulation respectively.
干预措施: Sham Transcranial alternating current stimulation (Device)
结局指标
主要结局
Working Memory behavioral performance
时间窗: During procedure (20 minutes)
Participants view a continuous sequence of alphabet letters, presented as stimuli in Arial font, size 120pt, on a tube screen positioned at 60cm eye distance. The stimuli are shown with a time interval of two seconds between them. The task consisted of six blocks with 70 stimuli, including 12 possible hit trials. Participants were instructed to press the left key on a response box if the presented stimulus matched either the one presented one trial prior (1-Back) or three trials prior (3-Back). In all other cases, participants press the right key. The left button is pressed with the index finger, while the right button is pressed with the middle finger of the right hand, with buttons aligned horizontally. The response condition varied by block, with three blocks for 3-Back and three for 1-Back, and the order was counterbalanced across participants and sessions.
electroencephalogram (EEG) oscillatory power
时间窗: up to 2 hours after the intervention
Change in the EEG power in the gamma band
electroencephalogram (EEG) functional connectivity
时间窗: up to 2 hours after the intervention
Change in EEG functional connectivity, specifically global efficiency, coherence, and phase-locking value at gamma frequency
次要结局
- electroencephalogram (EEG) oscillatory power(up to 2 hours after the intervention)
研究者
Mohammad Ali Salehinejad
Principal Investigator
Technical University of Dortmund