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Completed

NCT Number: NCT01738295

Donepezil Effect on Visual Attention and Training

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.

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Key information

Conditions

Healthy

Age range

20 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

School of optometry / Université de Montréal

Montreal, Quebec, H3T 1P1, Canada

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Donepezil administration

Drug

Other names: Aricept, Pfizer

Placebo Administration

Drug

Other names: Lactose pill

Primary outcomes

  1. Measure of the speed threshold, baseline

    Time frame: 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

  2. Change from baseline of the speed threshold at 1 week

    Time frame: 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.

  3. Change from baseline of the speed threshold at 2 weeks

    Time frame: 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.

  4. Change from baseline of the speed threshold at 3 weeks

    Time frame: 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.

  5. Change from baseline of the speed threshold at 4 weeks

    Time frame: 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.

Sponsors and collaborators

Lead sponsor

Université de Montréal

Other

Registry information

Official study title

Donepezil Effect on Visual Attention and Perceptual Training in Healthy Young Adults

Important dates

Study start
2013
Primary completion
2014
Study completion
2015
First posted
Nov 30, 2012
Registry last updated
Jun 5, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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