ABSTRACT

Search for a target defined by a conjunction of movement and shape (moving X amongst moving Os and static Xs) is efficient, with static distractors contributing little to RT. How search is restricted to the moving items, whilst static items are ignored is not fully understood. Whether, passive bottom-up, or active top-down control processes are recruited is unknown. The current study addressed this question by asking participants to search for a motion–shape conjunction target under a low (one-digit) or high (six-digit) memory load. In Experiment 1, the number of distractors with target motion (moving Os), shape (static Xs), or neither (static O) was varied. RT was most sensitive to the number of moving items, less sensitive to the number of target-shaped items, and insensitive to the number of items without target features. A six-digit load slowed responding, but the effect of increasing distractor numerosity remained unchanged. Experiment 2 compared conjunction against feature (moving X amongst moving and static Os) search. Both searches were slowed by a high memory load but search slope remained unchanged. The results are consistent with the idea that sustained distractor rejection in motion–form conjunction search is largely insensitive to cognitive load.

摘要

搜索由运动和形状（在移动的 Os 和静态 X 之间移动 X）定义的目标是有效的，静态干扰对 RT 的贡献很小。搜索如何仅限于移动项目，而忽略静态项目尚不完全清楚。是否采用被动自下而上或主动自上而下的控制过程是未知的。目前的研究通过要求参与者在低（一位数）或高（六位数）记忆负荷下搜索运动形状连接目标来解决这个问题。在实验 1 中，具有目标运动（移动 Os）、形状（静态 Xs）或两者都没有（静态 O）的干扰物的数量发生了变化。RT对移动的物品数量最敏感，对目标形状的物品数量不太敏感，对没有目标特征的物品数量不敏感。六位数的负载减慢了响应，但增加干扰数量的效果保持不变。实验 2 比较了联合与特征（在移动和静态 Os 之间移动 X）搜索。两次搜索都因高内存负载而减慢，但搜索斜率保持不变。结果与运动形式联合搜索中持续的干扰物拒绝在很大程度上对认知负荷不敏感的观点一致。