Mind the step: complementary effects of an implicit task on eye and head movements in real-life gaze allocation
Mind the step: complementary effects of an implicit task on eye and head movements in real-life gaze allocation
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DOI：
10.1007/s00221-012-3254-x
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发表时间：
2012-11-01
影响因子：
2
通讯作者：
Einhaeuser, Wolfgang
中科院分区：
文献类型：
--
作者：
't Hart, Bernard Marius;Einhaeuser, Wolfgang
现实世界中的凝视是由各种各样的参数控制的，例如刺激特征，指令或上下文，所有这些都已在实验室研究中进行了系统的研究。然而，目前还不清楚这些结果如何转移到现实世界的情况下，当参与者在很大程度上不受约束的行为。在这里，我们测量眼睛和头部的方向和凝视在两种情况下，我们要求参与者在现实世界的户外环境中协商路径。隐式任务集通过使用不同不规则的路径而变化：在一种条件下，路径由不规则放置的步骤组成，而在另一种条件下，使用鹅卵石路。在两条路径相邻定位的情况下，视觉环境（即，上下文和特征）对于这两个条件几乎是相同的，指令也是如此。我们发现，地形的规律性导致头部方向和凝视行为的差异，特别是在垂直方向。当地形不规则性增加时，参与者将头和眼睛放低。虽然头部方向不受影响，但对于更不规则的地形，头中眼方向的垂直扩展也显著增加。这伴随着眼球运动模式的改变，这补偿了较低的平均注视，仍然检查视觉环境。我们的研究结果量化了内隐任务需求在真实的世界中对注视分配的重要性，并暗示了眼睛和头部在注视分配中的不同贡献。这强调了从受约束的实验室数据推断真实世界行为时需要注意的问题。
Gaze in real-world scenarios is controlled by a huge variety of parameters, such as stimulus features, instructions or context, all of which have been studied systematically in laboratory studies. It is, however, unclear how these results transfer to real-world situations, when participants are largely unconstrained in their behavior. Here we measure eye and head orientation and gaze in two conditions, in which we ask participants to negotiate paths in a real-world outdoor environment. The implicit task set is varied by using paths of different irregularity: In one condition, the path consists of irregularly placed steps, and in the other condition, a cobbled road is used. With both paths located adjacently, the visual environment (i.e., context and features) for both conditions is virtually identical, as is the instruction. We show that terrain regularity causes differences in head orientation and gaze behavior, specifically in the vertical direction. Participants direct head and eyes lower when terrain irregularity increases. While head orientation is not affected otherwise, vertical spread of eye-in-head orientation also increases significantly for more irregular terrain. This is accompanied by altered patterns of eye movements, which compensate for the lower average gaze to still inspect the visual environment. Our results quantify the importance of implicit task demands for gaze allocation in the real world, and imply qualitatively distinct contributions of eyes and head in gaze allocation. This underlines the care that needs to be taken when inferring real-world behavior from constrained laboratory data.