Clinical trial NCT01738295: Donepezil Effect on Visual Attention and Training
Official title: Donepezil Effect on Visual Attention and Perceptual Training in Healthy Young Adults
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy
Keywords: acetylcholine
cholinergic system
visual perception
visual attention
multiple objects tracking
perceptual learning
vision training
Lead sponsor: Université de Montréal
Sponsor class: OTHER
First posted: 2012-11-30
Enrollment: 20
Sex: ALL
Minimum age (years): 20
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

Brief summary: 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.

Detailed description: Stages of a given perceptual-cognitive task (from Faubert and Sidebottom, Journal of Clinical Sport Psychology, 2012, 6, 85-102):

1. a predetermined number of spheres (typically eight) are presented in a 3D dimensional virtual volumetric cube space. The spheres are typically all identical.
2. a subset of spheres (typically four) is indexed via highlighting for a brief period of 1 s.
3. 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.
4. 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.

Eligibility criteria: Inclusion Criteria:

* good general health
* 17 \< body mass index \< 25
* visual acuity 6/6
* visual stereoscopy \> 50
* standard visual field

Exclusion Criteria:

* pregnancy or breast feeding
* use of any drug or St John's wort
* smoking
* asthma
* pulmonary obstruction
* cardiovascular impairment
* attention troubles
* ocular diseases
* epilepsy
* lactose intolerance
* absorption of grapefruit juice

Primary outcomes:
measure: Measure of the speed threshold, baseline
timeFrame: week 0
measure: Change from baseline of the speed threshold at 1 week
timeFrame: week 1
measure: Change from baseline of the speed threshold at 2 weeks
timeFrame: week 2
measure: Change from baseline of the speed threshold at 3 weeks
timeFrame: week 3
measure: Change from baseline of the speed threshold at 4 weeks
timeFrame: week 4
Secondary outcomes:
Other outcomes:
Locations:
city: Montréal
country: Canada
facility: School of optometry / Université de Montréal
state: Quebec
Study officials:
affiliation: Université de Montréal
name: Elvire Vaucher, PhD
role: STUDY_DIRECTOR
affiliation: Université de Montréal
name: Jocelyn Faubert, PhD
role: STUDY_DIRECTOR
affiliation: Université de Montréal
name: Isabelle Legault, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Université de Montréal
name: Mira Chamoun, MSc
role: PRINCIPAL_INVESTIGATOR
References: