Top-Down, Bottom-Up Attentional Processing. The Traditional View

There is a similarity between top-down and bottom-up deployments of attention. First and foremost, although the reason for attentional deployment is different, the effects of the two are largely the same. In both cases, the attended objects receive preferential processing, and, in both cases, this leads to an increased neural response, which has functional consequences, such as better memory storage. Top-down attention is also referred to as endogenous or sustained attention, and bottom-up attention is commonly typified as exogenous or transient attention. There are also important differences between both types of attention. Top-down attention is labeled endogenous because, unlike bottom-up attention (which is considered automatic/involuntary), it is under clear voluntary control. Importantly, top-down attention is more sustained, as individuals typically direct their top-down attention at stimuli for sustained periods of time, whereas bottom-up attention is transiently captured. Finally, top-down attention seems to take longer to deploy than bottom-up attention. The properties of both constructs are elucidated, and implications for executive function and attention deficit hyperactivity disorder are highlighted.