Donepezil Effect on Visual Attention and Perceptual Training in Healthy Young Adults
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Measure of the speed threshold, baseline
研究概览
简要总结
The present proposal investigates the role of the cholinergic system (the neurotransmitter acetylcholine) in improving vision and visual attention. Vision results from a complex processing of particular stimuli of the visual field. Attention enhances and prolongs the neural representations of visual input in the visual cortex. It has recently been shown that attention in the visual cortex depends on cholinergic mechanisms. The action of acetylcholine in the visual cortex consists in enhancement of the responsiveness to thalamocortical inputs, depression of local neuronal connections or extrastriate feedback projections and induction of gamma synchronisation. The investigators hypothesize that these effects are associated with long-term changes in functional connectivity in the visual cortex, visual attention and visual learning (improvement of the visual capacities).
In the present proposal, the investigators will test whether the administration of donepezil (Aricept, 5mg), a drug that increases the level of acetylcholine in the brain, will enhances the perceptual-cognitive abilities of young adult subjects. Perceptual-cognitive performance will be assessed in a multiple object tracking (MOT) task in a 3D automatic virtual environment. MOT is a task where observers are asked to maintain attentional focus on a limited number of preselected subgroup of elements in a dynamic scene. Multifocal attentional mechanisms are necessary to process the information. The task will be tested five time at one week interval to test whether donepezil and training improved the task performance of the subject, i.e. lead to perceptual learning. This study could help establish an intervention procedure to improve visual performance of subjects that need it.
详细描述
Stages of a given perceptual-cognitive task (from Faubert and Sidebottom, Journal of Clinical Sport Psychology, 2012, 6, 85-102):
- a predetermined number of spheres (typically eight) are presented in a 3D dimensional virtual volumetric cube space. The spheres are typically all identical.
- a subset of spheres (typically four) is indexed via highlighting for a brief period of 1 s.
- the spheres return to their original color and start moving within the restricted 3D virtual space. During this movement, the spheres can collide and consequently suddenly change direction, and they can cross over others, thus occluding their view.
- the spheres stop moving after a predetermined time, and the observer has to identify the spheres that were initially indexed with halos. The subject is then given feedback on the response by having the spheres identified by revealing the appropriate indexed stimuli.
The main task starts at a given speed, and if all four spheres are not correctly identified, the next trial will be slower. If the four spheres are correctly identified, then the next trial will be faster. Trials are repeated like this following a staircase procedure, and ultimately, a speed threshold is established.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 20 Years 至 35 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •good general health
- •17 < body mass index < 25
- •visual acuity 6/6
- •visual stereoscopy > 50
- •standard visual field
排除标准
- •pregnancy or breast feeding
- •use of any drug or St John's wort
- •pulmonary obstruction
- •cardiovascular impairment
- •attention troubles
- •ocular diseases
- •lactose intolerance
- •absorption of grapefruit juice
研究组 & 干预措施
Donepezil
Donepezil administration. In this group Donepezil (Aricept pill, 5 mg) will be orally administrated 3h before each experiment (1 week intervals)
干预措施: Donepezil administration (Drug)
Lactose pill
Placebo administration. In this group, placebo (lactose pill) will be orally administrated 3h before each experiments (1 week intervals)
干预措施: Placebo administration (Drug)
结局指标
主要结局
Measure of the speed threshold, baseline
时间窗: week 0
The speed of the moving spheres is increased across trials until the subject is not able anymore to track and identify the indexed spheres (speed threshold). In this baseline task, the subject will not take Donepezil or placebo
Change from baseline of the speed threshold at 1 week
时间窗: week 1
The speed of the moving spheres is increased across trials. The maximal speed for which the subject is able to track and identify the indexed spheres is the speed threshold. At this time point, the effect of Donepezil (5 mg, single dose) or placebo administration on the perceptual-cognitive performance will be assessed.
Change from baseline of the speed threshold at 2 weeks
时间窗: week 2
The speed of the moving spheres is increased across trials. The maximal speed for which the subject is able to track and identify the indexed spheres is the speed threshold. At this time point, the effect of Donepezil (5 mg, single dose) or placebo administration on the perceptual-cognitive performance will be assessed.
Change from baseline of the speed threshold at 3 weeks
时间窗: week 3
The speed of the moving spheres is increased across trials. The maximal speed for which the subject is able to track and identify the indexed spheres is the speed threshold. At this time point, the effect of Donepezil (5 mg, single dose) or placebo administration on the perceptual-cognitive performance will be assessed.
Change from baseline of the speed threshold at 4 weeks
时间窗: week 4
The speed of the moving spheres is increased across trials. The maximal speed for which the subject is able to track and identify the indexed spheres is the speed threshold. At this time point, the effect of Donepezil (5 mg, single dose) or placebo administration on the perceptual-cognitive performance will be assessed.
次要结局
未报告次要终点
研究者
Elvire Vaucher
Associate professor
Université de Montréal