Abstract
Learning from experience underlies our ability to adapt to novel tasks and unfamiliar environments. But how does the visual system know when to adapt and change and when to remain stable? The neurotransmitter acetylcholine (ACh) has been shown to play a critical role in cognitive processes such as attention and learning. Previous research in animal models has shown that plasticity in sensory systems often depends on the task relevance of the stimulus, but experimentally increasing ACh in cortex can replace task relevance in inducing experience-dependent plasticity. Perceptual learning (PL) is a specific and persistent improvement in performance of a perceptual task with training. To test the role of ACh in PL of visual discrimination, we pharmacologically enhanced cholinergic transmission in the brains of healthy human participants by administering the cholinesterase inhibitor donepezil (trade name: Aricept), a commonly prescribed treatment for Alzheimer’s disease. To directly evaluate the effect of cholinergic enhancement, we conducted a double-blind, placebo-controlled cross-over study, in which each subject participated in a course of training under placebo and a course of training under donepezil. We found that, relative to placebo, donepezil increased the magnitude and specificity of the improvement in perceptual performance following PL. These results suggest that ACh plays a role in highlighting occasions in which learning should occur. Specifically, ACh may regulate neural plasticity by selectively increasing responses of neurons to behaviorally relevant stimuli.
Meeting abstract presented at VSS 2012