Attentional shift (or shift of attention) occurs when directing attention to a point increases the efficiency of processing of that point and includes inhibition to decrease attentional resources to unwanted or irrelevant inputs.[1][page needed] Shifting of attention is needed to allocate attentional resources to more efficiently process information from a stimulus. Research has shown that when an object or area is attended, processing operates more efficiently.[2][3] Task switching costs occur when performance on a task suffers due to the increased effort added in shifting attention.[1] There are competing theories that attempt to explain why and how attention is shifted as well as how attention is moved through space in attentional control.