At low levels of arousal, our attention mechanisms are not particularly active and our performance capability is low. Complacency and boredom can result. At the other end of the curve, performance deteriorates when arousal becomes too high. This is because we are forced to shed tasks and focus only on key information. This is called narrowing of attention. Best task performance occurs somewhere in the middle. In the work place, arousal is mainly influenced by stimulation due to work tasks. However, surrounding environmental factors such as noise may also influence the level of arousal.