Spatial attention is the ability to focus on specific stimuli in a visual environment. When people look at scenes, although they may feel like they are looking at a complex mixture of stimuli, their attention is actually drawn to a handful of critical pieces of data. The brain identifies the most important information in the scene for further examination and the coordinated planning of movements. In people with neurological disorders, errors of this type of attention can develop.
A classic example of spatial attention comes up in driving, where people are bombarded by stimuli. Scenery moves outside the car while the driver attempts to stay on the road and maintain a safe distance from other vehicles. The brain, rather than processing meaningless and unimportant information, focuses on the most relevant data. This can include things like road signs, the car directly in front of the driver, and so forth.
People are not born with innate spatial attention abilities. Instead, these develop over time as infants interact with their environment. In early childhood development, activities like grasping for toys and navigating the world provide valuable information for future tasks requiring this skill. Children learn how to orient themselves in space and how to find the most pertinent information in an environment. A pony-obsessed young child, for example, would develop these skills to focus on ponies and pony-like objects.
The brain also utilizes special protocols to address new information. As data enters the visual field, the brain can decide both whether it is important, and just how it important it is. Rapid processing allows for the immediate prioritization of any threats. This could include things like flying or falling objects, dangerous animals, or other sources of danger. The brain rivets attention on these until the problem is resolved, and then it can return to more ordinary visual processing.
Researchers with an interest in visual processing and explorations of how the brain works may conduct studies to learn more about spatial attention in people with neurological problems. Some people may not be able to redirect focus to threats in the environment, for example, or could have selective processing that varies between the eyes. Others may have difficulty with sorting through numerous stimuli, which can result in a sense of overload as the brain tries to deal with competing information. Some patients with autism, for example, have trouble ranking the importance of objects in their environment and thus perceive scenes very differently from the people around them.