The chemical, AcetylCholine (ACh), had been known to increase the activity of individual neurons; it had not previously been shown that this activity enhancement leads to enhanced vision.
In the study, the researchers looked at the brain's nicotinic AcetylCholine receptors (nAChR), to which ACh binds to stimulate neural activity. Nicotinic receptors are named for the fact that they also bind nicotine, the addictive chemical in cigarettes.
ACh is a neurotransmitter, a chemical used to relay, amplify, and modulate signals between neurons and between neurons and other cells.
The analysis of the study found that information, which comes into the brain's visual cortex could be selectively enhanced by mimicking the effects of ACh with nicotine, resulting in the ability of neurons to detect, and to signal, stimuli that, without ACh's enhancement, were below detection threshold.
"That's what attention does--it strengthens the signal you're interested in and that strengthening helps you filter out other things," Disney said.
"Our findings show that acetylcholine has the ability to turn up the volume on visual activity, just like attention does," she added.