Dataset for paper "Dogs’ ability to follow the trajectory of temporarily invisible moving objects: ability to track and expect are shaped by experience"

Visually tracking a moving object, even if it becomes temporarily invisible, is an important skill for animals living in complex environments. However, this ability has not been widely explored in dogs. To address this gap of knowledge and understand how experience contributes to such ability, we conducted two experiments using a violation of expectation paradigm. Dogs were shown an animation of a ball moving horizontally across a screen, passing behind an occluder, and reappearing with a timing that was faster, slower or congruent with its initial speed. In the first experiment, dogs (N=15) were exposed to the incongruent conditions without prior experience, while in the second experiment dogs (N=37) were preliminarily exposed to the congruent stimulus. Dogs of the first experiment did not exhibit a surprise effect in response to the incongruent conditions, suggesting they had not formed an expectation about the timing of reappearance. However, their latency to orient towards the reappearing ball depended on the condition, suggesting they were able, to some extent, to visually keep track of the stimulus’ trajectory. Dogs of the second experiment were surprised when the ball stayed behind the occluder longer than expected, but showed no difference in latency to orient across conditions. This suggests they had overcome the visual-tracking mechanism and had formed an expectation about the timing of reappearance. In conclusion, dogs seem to use a low-level mechanism to keep visual track of a temporarily disappearing moving object, but experience is required to make expectation about its trajectory.

在复杂环境中生活的动物，即便物体短暂地消失，视觉跟踪移动目标亦是一项至关重要的技能。然而，这种能力在犬类的研究中尚未得到广泛探讨。为填补这一知识空白，并探究经验如何影响此类能力，本研究采用违反预期范式，开展了两项实验。实验中，犬类被展示了一段动画，其中球体在屏幕上水平移动，穿过遮挡物后以比初始速度更快、更慢或与之同步的时机重新出现。在第一项实验中（N=15），犬类在未接受预先经验的情况下，接触到了违反预期的条件；而在第二项实验中（N=37），犬类首先接触到了与之同步的刺激。结果显示，第一组实验中的犬类在面对违反预期的条件时并未表现出惊讶效应，这表明它们尚未形成关于重新出现时机的预期。然而，它们朝向重新出现的球体的反应潜伏期依赖于条件，这表明它们在一定程度上能够视觉上追踪刺激的轨迹。第二组实验中的犬类在球体在遮挡物后停留的时间超出预期时感到惊讶，但在不同条件下的反应潜伏期上并未显示出差异。这表明它们已克服视觉跟踪机制，并对重新出现的时间形成了预期。综上所述，犬类似乎利用低级机制来保持对暂时消失的移动目标的视觉追踪，但形成关于其轨迹的预期则需要经验。