Summary
Explicitly or implicitly, there are currently three competing models for the role of the neuromodulator acetylcholine (ACh) in attention. The first asserts that the cholinergic system is spatially imprecise and contributes to a mechanism for arousal but not attention. The second states that the cholinergic system is spatially imprecise and is one component of the mechanism for attention. The third states that the cholinergic system is at the center of the mechanism for attention (implying the system is sufficiently spatially precise to play such a role). In this study, I will test these three
