Reading this story requires you to willfully pay attention to the sentences and to tune out nearby conversations, the radio and other distractions.
But if a fire alarm sounded, your attention would be involuntarily snatched away from this story towards the blaring sound.
New research from Vanderbilt University reveals for the first time how our brains coordinate these two types of attention, and why we may be temporarily blinded by surprises.
"The simple example of having your reading interrupted by a fire alarm illustrates a fundamental aspect of attention: what ultimately reaches our awareness and guides our behaviour, depends on the interaction between Goal-directed and Stimulus-driven attention.
For coherent behaviour to emerge, you need these two forms of attention to be coordinated," René Marois, associate professor of psychology and co-author of the new study, said. "We found a brain area, the Inferior Frontal Junction, that may play a primary role in coordinating these two forms of attention."
The researchers were also interested in what happens to us when our attention is captured by an unexpected event.
"We wanted to understand what caused limitations in our conscious perception when we are surprised," Christopher Asplund, a graduate student in the Department of Psychology and primary author of the new study, said. "We found that when shown a surprise stimulus, we are temporarily blinded to subsequent events."
Using fMRI scanning, the researchers found that the Inferior Frontal Junction, a region of the lateral prefrontal cortex, was involved in both the original task and in the reaction to the surprise.
"What we think might be happening is that this brain area is coordinating different attention systems -- it has a pre-defined response, both when you are controlling your attention and when you feel as though your attention is distracted or jerked away," Asplund said.
The researchers hypothesise that we may be temporarily blinded by surprise because the surprise stimulus and subsequent response occupies so much of our processing ability.
"The idea is not so strange or difficult to understand, we can't attend to everything at once," Asplund said. "It seems that the Inferior Frontal Junction is involved in this limitation in attention."
The new research supports previous work by Marois' laboratory that found the interior frontal junction plays the role of an attentional bottleneck -- limiting our ability to multitask and attend to many things at once.
"These new findings and our previous findings suggest that this area is centrally involved in the control of attention and may limit our attentional capacities," Marois said. "It is a very exciting convergence of findings across our studies. We're conducting studies now to demonstrate whether in fact disruption of activity in this brain region leads to loss of control of attention."
If you want to know more or wish to read the full study click on this link
Another useful link and very professional website is Vanderbilt's Online Research Magazine