Rationale: Selective cholinergic receptor agonists and antagonists have been shown to modulate inspection time, a measure of speed of early information processing.
Objective: The present study aimed to examine the effects of globally increasing cholinergic function with the acetylcholinesterase inhibitor donepezil on inspection time.
Methods: Fourteen healthy subjects participated in a randomised double-blind, placebo controlled trial in which all subjects were tested under either acute placebo or donepezil (5 mg) treatment conditions. Testing was conducted pre- and 90 min post-drug administration.
Results: There was a significant decrease in inspection time in the donepezil condition compared to the placebo condition (F = 12.86; P < 0.01).
Discussion: The decrease or improvement of inspection time following donepezil administration is consistent with the role of the cholinergic system in modulating speed of information processing, and adds evidence that inspection time may serve as a physiological index of the integrity of the cholinergic system.