Attention is sometimes defined as the ability to select part of the environment, focus on that part, and disregard the rest. At any point in time, there are a host of sights, sounds and stimuli in the environment which are ignored, while some subset receives attention. Attention has been conceptualized as a spotlight directed at those stimuli or thoughts currently being processed. Attention may be directed under conscious control (as when a student concentrates on memorizing his notes) or may shift according to external stimuli (as when we look to find the source of a startling noise). Divided attention refers to the ability to process multiple inputs at once, as in being able to drive a car and carry on a conversation at the same time.

Items which receive attention are more likely to enter into long-term memory, while unattended items are more likely to be forgotten.

Several areas of the brain have been implicated in attention, including the arousal centers in the brainstem, and the frontal lobes, which are involved in executive functions such as judgment and abstract thought. Schizophrenia is sometimes characterized as an attentional disorder, in which patients cannot "tune out" all the many irrelevant stimuli around them.

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Article : "MEMORY TIP #1"