Attention seekers: pinpointing the chemicals behind attention span
17 July 2008
Ever wondered why you sometimes need to read a page over and over again before its contents sink in? According to research published in this week's issue of Nature, a nervous system chemical called acetylcholine is vital for our brain cells to pay attention to a demanding task.
"For the first time we have been able to precisely identify the mechanism by which the brain implements a state of attention and increases awareness for important tasks," says Professor Alex Thiele from Newcastle University, who led the research.
Attention is essential for perception, awareness, learning and memory. This research is important because it increases understanding of how our brains work and also has potential use in the development of treatments for neurological conditions linked to awareness and attention, including Alzheimer's disease and attention-deficit hyperactivity disorder.
In the study, which was part-funded by the Wellcome Trust, Professor Thiele and colleagues used a primate model to explore the role in attention of acetylcholine - a naturally occurring chemical involved in signal transmission in the nervous system.
Researchers applied small amounts of acetylcholine to animals before they took part in an exercise demanding high attention. The receptors and nerve cells in the animals' brains showed greater activity associated with attention, and the animals showed an increased awareness of the task. Blocking specific acetylcholine receptors reversed this process and reduced attention.
"Our research shows that for to have full attention and awareness the neurons and specific receptors in the brain require a dose of acetylcholine to get them into the correct state," says Professor Thiele. "When this happens correctly the brain has higher levels of attention and has increased awareness of the task the individual is attempting to solve.
"If these mechanisms are not working properly then, most of the time, it means we have to re-read an article or we will miss something somebody says. Many of these processes in the brain have a role in conditions such as Alzheimer's disease, attention deficit disorders and other attention deficits. It will require more research but I hope that this work might be able to help sufferers in the future."
Image: Small girl concentrating on a picture book; John Wildgoose, Wellcome Images
References
Herrero JL et al. Acetylcholine contributes through muscarinic receptors to attentional modulation in V1. Nature 2008; doi:10.1038/nature07141 [Epub ahead of print]