Assessment Of The Effects Of Single Doses Of An Investigational Drug, Given Alone Or With Donepezil, On Scopolamine-Induced Changes In Memory And Learning In Healthy Adults

Inclusion Criteria: * Healthy male or female volunteers; females must be of non-childbearing potential. * Weight with normal limits for height. * Willing to comply with study schedule and able to complete 2 practice sessions (pre-study) with computerized memory and learning/problem solving tests. Exclusion Criteria: * Positive urine drug screen; concurrent use of prescription or over-the-counter (OTC) drugs or dietary supplements within 7 days or 5 half-lives prior to the first dose of study medication. * Use of medications with significant serotonergic, cholinergic or anticholinergic side effects \[SSRIs, pyridostigmine, tricyclic antidepressants, meclizine, oxybutynin\]) within 4 weeks of first dose of study drug. * Glaucoma * Abnormal electrocardiogram (ECG) * Treatment with an investigational drug within 30 days of dosing.