Classification of natural textures in echolocation
Classification of natural textures in echolocation
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DOI：
10.1073/pnas.0308029101
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发表时间：
2004-04-13
影响因子：
11.1
通讯作者：
Wiegrebe, L
中科院分区：
文献类型：
--
作者：
Grunwald, JE;Schörnich, S;Wiegrebe, L
通过回声定位，蝙蝠不仅可以感知黑暗中物体的位置，还可以感知物体的位置。它还可以识别其 3D 结构。然而，树是一个非常复杂的对象。它有数千个反射表面，导致树的声学图像变得混乱。从技术上讲，物体的声像是其脉冲响应（IR），即物体被声脉冲声化时记录的反射之和。从超声波回波中提取声红外以及详细的红外分析是蝙蝠非凡的物体识别能力的基础。在这里，开发了一个幻像对象回放实验，以证明蝙蝠 Phyllostomus discolor 可以评估混沌疾病的统计特性，即红外粗糙度。幻影物体的弊病由多达 4,000 个随机分布的反射组成。结果表明，P. discolor 根据红外粗糙度自发地对这些疾病产生的回波进行分类。这种能力使蝙蝠能够以有意义的方式评估复杂的自然纹理，例如树叶类型。目前的行为结果及其在蝙蝠上升听觉系统计算机模型中的模拟表明，调制敏感神经元参与了回声分析。
Through echolocation, a bat can perceive not only the position of an object in the dark; it can also recognize its 3D structure. A tree, however, is a very complex object; it has thousands of reflective surfaces that result in a chaotic acoustic image of the tree. Technically, the acoustic image of an object is its impulse response (IR), i.e., the sum of the reflections recorded when the object is ensonified with an acoustic impulse. The extraction of the acoustic IR from the ultrasonic echo and the detailed IR analysis underlies the bats' extraordinary object-recognition capabilities. Here, a phantom-object playback experiment is developed to demonstrate that the bat Phyllostomus discolor can evaluate a statistical property of chaotic Ills, the IR roughness. The Ills of the phantom objects consisted of up to 4,000 stochastically distributed reflections. It is shown that P. discolor spontaneously classifies echoes generated with these Ills according to IR roughness. This capability enables the bats to evaluate complex natural textures, such as foliage types, in a meaningful manner. The present behavioral results and their simulations in a computer model of the bats' ascending auditory system indicate the involvement of modulation-sensitive neurons in echo analysis.