Does donepezil improve visual stimuli detection and perceptivo-cognitive performance of heathy young adults ?
56.3006, Tuesday, 19-May, 2:45 pm - 6:45 pm, Banyan Breezeway
Mira Chamoun1, Frédéric Huppé-Gourgues1, Isabelle Legault2, Pedro Rosa-Neto3, Jocelyn Faubert2, Elvire Vaucher1; 1Laboratoire de neurobiologie de la cognition visuelle, Ecole d'optometrie Université de Montreal, 2Laboratoire de psychophysique et de perception visuelle, Ecole d'optometrie Université de Montreal, 3Laboratoire de neuroimagerie translationnelle (LNT), Institut Douglas Université McGill
Donepezil enhances the cholinergic synaptic transmission in the brain by inhibiting the enzyme that metabolizes acetylcholine in the synaptic cleft, thereby prolonging the action of this neurotransmitter. It has been demonstrated that chronic administration of donepezil increases perceptual learning. Our study examines the effect of acute administration of donepezil on first and second order visual stimuli detection on one hand and on perceptual-cognitive performance on the other hand. A double-blind, placebo controlled design was used to evaluate the effect of cholinergic enhancement - donepezil administration (5 mg, given per os) - on visual attention using two different attention tasks. 10 young healthy adults were enrolled in each group. The task was performed 3 hours after the donepezil (or placebo) intake to synchronize with the peak plasma concentration of the drug. We started by testing the first and second order visual detection for motion and direction using the Neurominder task (Habak & Faubert, 2000) before and after taking donepezil. Motion and direction identification thresholds for the first order and second order visual detection were identical before and after donepezil intake. The multifocal attention of the participant was tested by the multiple object tracking task (Legault and Faubert, 2012). During this perceptual-cognitive task, the observer is required to simultaneously track multiple moving items among distracters in a dynamic virtual reality environment. The task is repeated once a week during 5 weeks to test the effect of learning. The speed thresholds in the MOT task increased significantly in each session in the same range for both donepezil and control groups. Our results suggest that an acute 5mg dose of donepezil might not be sufficient to elicit perceptual-cognitive or visual detection performance improvement when given to healthy young subjects. Additional studies are needed to better define the involvement of acetylcholine enhancement on perceptual learning/attentional tasks.