Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218
Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218.
Proc Natl Acad Sci U S A. 2020 Nov 17;117(46):29229-29238. doi: 10.1073/pnas.2011719117. Epub 2020 Nov 2.
Unlike other predators that use vision as their primary sensory system, bats compute the three-dimensional (3D) position of flying insects from discrete echo snapshots, which raises questions about the strategies they employ to track and intercept erratically moving prey from interrupted sensory information. Here, we devised an ethologically inspired behavioral paradigm to directly test the hypothesis that echolocating bats build internal prediction models from dynamic acoustic stimuli to anticipate the future location of moving auditory targets. We quantified the direction of the bat's head/sonar beam aim and echolocation call rate as it tracked a target that moved across its sonar field and applied mathematical models to differentiate between nonpredictive and predictive tracking behaviors. We discovered that big brown bats accumulate information across echo sequences to anticipate an auditory target's future position. Further, when a moving target is hidden from view by an occluder during a portion of its trajectory, the bat continues to track its position using an internal model of the target's motion path. Our findings also reveal that the bat increases sonar call rate when its prediction of target trajectory is violated by a sudden change in target velocity. This shows that the bat rapidly adapts its sonar behavior to update internal models of auditory target trajectories, which would enable tracking of evasive prey. Collectively, these results demonstrate that the echolocating big brown bat integrates acoustic snapshots over time to build prediction models of a moving auditory target's trajectory and enable prey capture under conditions of uncertainty.
与其他使用视觉作为主要感觉系统的捕食者不同,蝙蝠从离散的回声快照中计算出飞行昆虫的三维(3D)位置,这就提出了一个问题,即它们采用何种策略来从中断的感觉信息中跟踪和拦截不稳定移动的猎物。在这里,我们设计了一种受生态学启发的行为范式,直接测试了这样一种假设,即回声定位蝙蝠从动态声刺激中构建内部预测模型,以预测移动听觉目标的未来位置。我们量化了蝙蝠在跟踪穿越其声纳场的目标时头部/声纳波束的方向和回声定位叫声率,并应用数学模型来区分非预测性和预测性跟踪行为。我们发现,大褐蝙蝠通过回声序列积累信息,以预测听觉目标的未来位置。此外,当运动目标在其轨迹的一部分被遮挡物遮挡而无法看到时,蝙蝠会继续使用目标运动路径的内部模型来跟踪其位置。我们的研究结果还表明,当目标速度突然变化违反了蝙蝠对目标轨迹的预测时,蝙蝠会增加声纳叫声率。这表明蝙蝠会迅速调整其声纳行为,以更新听觉目标轨迹的内部模型,从而能够在不确定的情况下跟踪逃避的猎物。总的来说,这些结果表明,回声定位的大褐蝙蝠会随着时间的推移整合声纳快照,以建立移动听觉目标轨迹的预测模型,并在不确定的条件下实现猎物捕获。