Bennett Christopher R, Bex Peter J, Merabet Lotfi B
The Laboratory for Visual Neuroplasticity, Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
Translational Vision Lab, Department of Psychology, Northeastern University, Boston, MA, USA.
J Vis. 2021 Jan 4;21(1):5. doi: 10.1167/jov.21.1.5.
Daily activities require the constant searching and tracking of visual targets in dynamic and complex scenes. Classic work assessing visual search performance has been dominated by the use of simple geometric shapes, patterns, and static backgrounds. Recently, there has been a shift toward investigating visual search in more naturalistic dynamic scenes using virtual reality (VR)-based paradigms. In this direction, we have developed a first-person perspective VR environment combined with eye tracking for the capture of a variety of objective measures. Participants were instructed to search for a preselected human target walking in a crowded hallway setting. Performance was quantified based on saccade and smooth pursuit ocular motor behavior. To assess the effect of task difficulty, we manipulated factors of the visual scene, including crowd density (i.e., number of surrounding distractors) and the presence of environmental clutter. In general, results showed a pattern of worsening performance with increasing crowd density. In contrast, the presence of visual clutter had no effect. These results demonstrate how visual search performance can be investigated using VR-based naturalistic dynamic scenes and with high behavioral relevance. This engaging platform may also have utility in assessing visual search in a variety of clinical populations of interest.
日常活动需要在动态且复杂的场景中持续搜索和追踪视觉目标。评估视觉搜索性能的经典研究主要使用简单的几何形状、图案和静态背景。最近，研究方向已转向使用基于虚拟现实（VR）的范式在更自然的动态场景中研究视觉搜索。在此方向上，我们开发了一种结合眼动追踪的第一人称视角VR环境，用于获取各种客观测量数据。参与者被要求在拥挤的走廊场景中搜索预先选定的正在行走的人类目标。根据扫视和平滑跟踪眼动行为对表现进行量化。为了评估任务难度的影响，我们对视觉场景的因素进行了操纵，包括人群密度（即周围干扰物的数量）和环境杂乱的存在情况。总体而言，结果显示随着人群密度增加，表现呈恶化趋势。相比之下，视觉杂乱的存在没有影响。这些结果证明了如何使用基于VR的自然动态场景并具有高度行为相关性来研究视觉搜索性能。这个引人入胜的平台在评估各种感兴趣的临床人群的视觉搜索方面也可能有用。
