Integration of dynamic emission and reception in the biosonar system of horseshoe bats

Abstract

Bats have evolved unique mechanisms by which to navigate and hunt in their environments. Some species of the microchiroptera, such as members of the horseshoe bat family (Rhinolophidae), which live in particularly challenging, cluttered environments, have been observed to move their peripheral structures for emission and reception (noseleaf and pinna) during echolocation very rapidly, e.g., within a tenth of a second. With these behaviors, the bats could create time-variant properties in their biosonar systems to provide additional degrees of freedom to be used for enhancing the encoding of sensory information. To make full use of this opportunity, a tight sensorimotor integration is likely to be required. In order to explore the possible role of sensorimotor integration in a dynamic biosonar system, we have developed biomimetic robotic models to replicate the effects of the dynamics of the baffle structures. Data obtained with these systems indicates that a coordinated emitter and receiver dynamics can both contribute to the embedding of time-variant signatures in the signals that encode information about target class. Ongoing research seeks to transition insights from work on the biomimetic design paradigms to data from brain recordings made in from the auditory brainstem and the superior colliculus of horseshoe bats.