Orlowski Julius, Ben-Shahar Ohad, Wagner Hermann
Institute of Biology II, RWTH Aachen University, Aachen, Germany.
Department of Computer Science, Ben-Gurion University, Beer-Sheva, Israel.
J Vis. 2018 Jan 1;18(1):4. doi: 10.1167/18.1.4.
How do we find what we are looking for? A target can be in plain view, but it may be detected only after extensive search. During a search we make directed attentional deployments like saccades to segment the scene until we detect the target. Depending on difficulty, the search may be fast with few attentional deployments or slow with many, shorter deployments. Here we study visual search in barn owls by tracking their overt attentional deployments-that is, their head movements-with a camera. We conducted a low-contrast feature search, a high-contrast orientation conjunction search, and a low-contrast orientation conjunction search, each with set sizes varying from 16 to 64 items. The barn owls were able to learn all of these tasks and showed serial search behavior. In a subsequent step, we analyzed how search behavior of owls changes with search complexity. We compared the search mechanisms in these three serial searches with results from pop-out searches our group had reported earlier. Saccade amplitude shortened and fixation duration increased in difficult searches. Also, in conjunction search saccades were guided toward items with shared target features. These data suggest that during visual search, barn owls utilize mechanisms similar to those that humans use.
我们如何找到我们正在寻找的东西？一个目标可能就在明视范围内，但可能要经过广泛搜索才能被发现。在搜索过程中，我们会进行有指向性的注意力部署，比如扫视以分割场景，直到我们检测到目标。根据难度不同，搜索可能通过较少的注意力部署而快速完成，也可能通过较多、较短的部署而缓慢完成。在这里，我们通过用摄像头跟踪仓鸮明显的注意力部署——即它们的头部运动——来研究仓鸮的视觉搜索。我们进行了低对比度特征搜索、高对比度方向联合搜索和低对比度方向联合搜索，每种搜索的集合大小从16个项目到64个项目不等。仓鸮能够学会所有这些任务，并表现出序列搜索行为。在随后的步骤中，我们分析了仓鸮的搜索行为如何随搜索复杂度而变化。我们将这三种序列搜索中的搜索机制与我们小组之前报告的弹出式搜索结果进行了比较。在困难的搜索中，扫视幅度缩短，注视持续时间增加。此外，在联合搜索中，扫视会导向具有共享目标特征的项目。这些数据表明，在视觉搜索过程中，仓鸮利用的机制与人类使用的机制类似。
