[ad_1]
Selective visual attention allows the brain to focus on important details while ignoring the rest, known as inattentional blindness. There are two types of visual processing: preattentive processing and focused attention. The focus range can be as small as one degree of the total visual field.
Selective visual attention allows a person to acquire a large amount of visual data from the environment, but engage with only a small part of it. There is a large amount of information that enters a person’s brain through the eyes, so the brain only processes a small portion of it, choosing to ignore the rest, an effect known as inattentional blindness. Although the brain continues to receive data from the entire visual field at once, most of this data is ignored most of the time. Instead, selective visual attention narrows the focus of the visual field to a smaller section of the total field so that a person can focus on details that are important at the moment.
There are two types of visual processing that take place within the human brain. The first is called preattentive processing and occurs simultaneously across a person’s entire visual field. This type of processing allows a person to notice changes in the environment. For example, an object that was previously motionless that has suddenly started moving or an object of a different color among objects of the same color will attract a person’s selective vision. Evolutionarily, this method of data preprocessing has allowed humans to survive in a hostile environment.
Once one or more objects have been selected out of the data field of preattentive processing, a person has focused attention on them. This object becomes the eye’s focal point and receives a large portion of working memory. However, the pre-attentive field remains active and can alert a person to another change in environment if one appears. Attention can be focused through the use of the top-down or bottom-up approach. In the top-down approach, deviations from the current environment trigger selective viewing, but in the bottom-up approach, attention is focused based on prior experiences and long-term memory expectations.
When people focus their attention on one thing in their field of vision, it is possible to go blind to other objects or events that the person can see. This happens because the brain determines that these other things are not as important as what the person is currently focusing on. The focus range of selective visual attention can be as small as one degree of the total visual field. Scientists aren’t sure how wide a person’s attention span can be.
[ad_2]