Abstract
This study investigates the effect of attention in the detection of direction changes when there are multiple objects. The participants were asked to detect direction changes while allocating their attention to objects marked by cues. Specifically, this study investigates how attention benefits change when attention must be allocated to multiple objects in order to detect direction-changes. The results showed that detection rate was in an inverse proportion to the number of objects, suggesting that it is difficult to simultaneously allocate attention to a large number of objects. The mechanisms for detecting direction-changes are discussed in terms of attention allocation.