1. Sustained attention and cognitive inhibition The Sustained Attention to Response Task (SART): The SART requires participants to make frequent responses to non-targets and to withhold a response to rarely presented targets. The task simply involves the sequential presentation of 297 single pictures (33 of each kind) presented over 6min. Subjects responded with a key press to each picture, except the 33 occasions when the designated picture appeared (refer to Figure 1). The response required to a non-target stimulus is simply the pressing of a mouse/keyboard, and targets are dispersed randomly in the sequence and occur no more often than 1 in 9 trials on average. In the SART, therefore, commission errors (failure to inhibit responding to a target) or "slips of action" are the result of brief lapses of sustained attention. In the Random SART, the target appears randomly therefore inhibition of a prepotent is essential as the requirement to inhibit a response is unpredictable. Therefore, this task looks at the ability to produce 'correct' inhibitions on inappropriate responses (Robertson et al., 1997).