What Is Attention and Why Is It Important ?

A fundamental characteristic of human cognition is our limited capacity for processing information. We cannot see, attend to, remember, or react to everything that we encounter in our environment. Nowhere does this limited capacity play a more central role than with attention. This attentional bottleneck implies that paying attention to one source of information causes the processing of other things to suffer. For example, when a driver of a motor vehicle begins to chat on a cell phone, the driver’s performance degrades as attention is withdrawn from driving and directed toward the phone conversation. Another important characteristic of attention is that it can be fl exibly allocated, based on the task demands and goals of the operator. In the following paragraphs, we briefl y describe the varieties of attention. Selective attention refers to the ability to selectively process some sources of information while ignoring others (Johnston & Dark 1986). Given that we cannot process all the information that is constantly bombarding our sensory systems, it is important to be able to select the information that is most important to our current set of goals for further processing and exclude irrelevant sources of information from analysis. Researchers speculate that a combination of facilitatory and inhibitory processes work together to aid in the selective processing of the environment (e.g., Houghton & Tipper 1994). Facilitatory processes are assumed to amplify the processing of task-relevant information and inhibitory processes dampen the processing of irrelevant information. For the most part, the mechanisms of selection are quite effective. People are good at selectively processing task-relevant information and excluding irrelevant material, although performance is not always perfect. In the extreme, attention-related patient disorders, such as schizophrenia, provide examples where patients fail to effectively suppress the processing of irrelevant stimuli or thoughts (Beech et al. 1989). Divided attention refers to the ability to perform two or more concurrent tasks or activities. In this context, attention has been conceptualized as a commodity that can be fl exibly allocated between different tasks, based on the processing priority assigned to each (Kahneman 1973; Navon & Gopher 1979). Because the capacity of attention is