Chapter 81. Selective Attention and Multitasking

1. We are constantly bombarded with more information than we can handle effectively. Our sensory systems supply the brain with millions of pieces of information every second. To make sense of that information overload, the brain's perceptual networks must focus on a small subset of this input and ignore the rest of the information.

2. Selective attention is a cognitive process that allows us to concentrate on one aspect of the environment—making it the focus of our consciousness—while ignoring the rest. This works amazingly well in allowing us to zoom in on relevant information as we screen out distracting input.

3. Selective attention applies to all our our sensory systems. For example, it allows us to focus on, and understand, a single conversation in a room filled with people talking (the cocktail party effect). In some cases, we can ignore the person speaking directly to us and instead pay attention to a conversation on the other side of the room.

4. Occasionally, selective attention causes us to miss some important events in our environment—a phenomenon called inattentional blindness. If you have ever missed a highway exit because you were talking to someone, or had your pocket picked while watching a musical performance, you've experienced the negative side of selective attention.

5. The point to remember: Having selective attention means that we are consciously aware of only a small fraction of the objects and events that surround us.

6. What about multitasking? Aren’t people supposed to be able to do several things at once?
The evidence suggests that true multitasking is only possible for cognitive tasks that allow
parallel processing by different regions of the brain. For example, it’s possible to pay attention to the color of a bird and its direction of movement at the same time, because different neural networks are devoted to processing what the object is (shape and color) and where the object is (location and movement).

7. Research demonstrates that true multitasking is not possible when both tasks require attention, or when both tasks utilize the same brain areas or neural networks. Many students believe that they can watch television while simultaneously carrying on a phone conversation. Rather than multitasking, they are engaged in task switching, which shifts attention rapidly between the two tasks, with some loss of information.

When we are driving a car, the visual environment changes constantly. Selective attention means that we don’t notice all of the changes, but instead only see the things to which we pay attention.

When some of our attention is diverted to an auditory task, such as a cell phone conversation, the result can be inattentional blindness for important visual objects, such as road signs and other vehicles.

This animation shows the eye movements of a typical driver while paying full attention to the road conditions. Each red dot represents an eye movement, as the driver glances back and forth between the mirrors, the instrument panel, and the road ahead.