The spatial and temporal resolution of bat sonar

蝙蝠声纳的空间和时间分辨率

• 批准号: 73153028
• 负责人: Professor Dr. Lutz Wiegrebe (†)
• 金额: --
• 依托单位: Department Biologie II (aufgelöst)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/73153028?language=en
• 关键词: spatial; temporal; resolution; bat; sonar

Ultrasonic echo imaging enables bats not only to orient through complex environments in total darkness, but also to identify complex, three-dimensional objects in space. When a bat ensonifies a natural echo-acoustic scene, many echoes will impinge almost simultaneously from many different directions onto the bats’ ears. To date there is nothing known about the bats’ capability to spatially resolve single reflectors from this multitude of echoes. Within this grant proposal, the spatial resolution of bat sonar is investigated in a series of formal psychophysical phantomtarget experiments: In a six-channel, two-alternative, forced-choice setup, the echolocating bat Phyllostomus discolor will be trained to detect a rewarded phantomtarget surrounded by masking phantom targets. The recruitment of multiple maskers allows quantifying sonar spatial receptive fields perceptually and comparing these with the directionality of the sonar beam, the directionality of the bats’ outer ears, and electrophysiologically measured spatio-temporal receptive fields. The phantom-target technique allows manipulating not only spatial but also temporal and spectral characteristics of the target and masker reflections. Specifically, the contributions of differences in echo delay or spectral content between signal- and masker reflections onto spatial unmasking will be assessed. These experiments will gain a detailed insight into how echolocating bats exploit the spatial characteristics of their sonar system to inspect complex echo-acoustic scenes in space.

超声波回声成像不仅使蝙蝠能够在完全黑暗的复杂环境中确定方向，还能识别空间中复杂的三维物体。当蝙蝠感知自然回声声场景时，许多回声几乎同时从许多不同方向撞击到蝙蝠的耳朵上。迄今为止，我们对蝙蝠从大量回声中空间解析单个反射器的能力一无所知。在这项资助提案中，蝙蝠声纳的空间分辨率在一系列正式的心理物理学幻影目标实验中进行了研究：在六通道、两个替代、强制选择设置中，回声定位蝙蝠Phyllosttomus discolor将被训练以检测被掩蔽幻影目标包围的奖励幻影目标。多个掩蔽器的招募允许在感知上量化声纳空间感受野，并将其与声纳束的方向性、蝙蝠外耳的方向性以及电生理学测量的时空感受野进行比较。幻影目标技术不仅可以操纵目标和掩蔽反射的空间特征，还可以操纵时间和光谱特征。具体来说，将评估信号反射和掩蔽反射之间的回声延迟或频谱内容差异对空间去掩蔽的影响。这些实验将详细了解回声定位蝙蝠如何利用其声纳系统的空间特征来检查空间中复杂的回声声场景。