Theeuwes J
TNO Institute for Perception, Soesterberg, The Netherlands.
Percept Psychophys. 1992 Jun;51(6):599-606. doi: 10.3758/bf03211656.
Three visual-search experiments tested whether the preattentive parallel stage can selectively guide the attentive stage to a particular known-to-be-relevant target feature. Subjects searched multielement displays for a salient green circle that had a unique form when surrounded by green nontarget squares or had a unique color when surrounded by red nontarget circles. In the distractor conditions, a salient item in the other dimension was present as well. As an extension of earlier findings (Theeuwes, 1991), the results showed that complete top-down selectivity toward a particular feature was not possible, not even after extended and consistent practice. The results reveal that selectivity depends on the relative discriminability of the stimulus dimensions: the presence of an irrelevant item with a unique color interferes with parallel search for a unique form, and vice versa.
三项视觉搜索实验测试了前注意平行阶段是否能够有选择地将注意阶段引导至特定的已知相关目标特征上。实验中，被试在多元素显示中搜索一个突出的绿色圆圈，该圆圈在被绿色非目标方块包围时具有独特形状，或者在被红色非目标圆圈包围时具有独特颜色。在干扰条件下，另一维度中的突出项目也会出现。作为早期研究结果（Theeuwes，1991）的扩展，结果表明，即使经过长时间且一致的练习，也不可能对特定特征实现完全的自上而下的选择性。结果显示，选择性取决于刺激维度的相对可辨别性：具有独特颜色的无关项目的存在会干扰对独特形状的平行搜索，反之亦然。
