Investigating spatial attention in echolocating bats

Tuninetti, Amaro

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Overview

Year:: 2023
Contributor:: Tuninetti, Amaro (creator); Simmons, Andrea (Advisor); Simmons, James (Reader); Song, Joo-Hyun (Reader); Moss, Cynthia (Reader); Brown University. Department of Cognitive, Linguistic, and Psychological Sciences (sponsor)
Genre:: theses
Subject:: Perception; Big Brown Bat; Bat sounds; Bioacoustics
Extent:: viii, 127 p.

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Description

Abstract:: Echolocating bats use an active perceptual system, also known as biosonar, that allows them to navigate and forage in complete darkness by emitting ultrasonic vocalizations and listening to the echoes that reflect off of nearby surfaces. Big brown bats (Eptesicus fuscus) are capable of navigating even in acoustically cluttered environments, which challenges their biosonar system to decipher multiple dynamic streams of echoes from numerous objects located at different distances and azimuths from the bat. Bats have highly specialized adaptations that allow them to accurately perceive their surroundings despite the presence of acoustic clutter. These include precisely controlling the directionality and timing of their biosonar emissions, which determine where in the acoustic scene the bat is attending. This dissertation presents three experiments investigating different aspects of spatial perception in big brown bats, with the aim of understanding the bat’s biosonar from multiple levels of analysis. Experiment 1 extends our understanding of how the big brown bat’s spatial perception is foveated in acuity on the basis of the frequency bandwidth of the bat’s echolocation beam. I trained bats to complete an active biosonar amplitude discrimination task and found that low-pass filtering of echoes results in lower amplitude perception acuity, similar to the effects of filtering on pulse-echo delay perception. Experiment 2 investigates how bats modulate their echolocation timing and direction when confronted with sudden changes in target location within a virtual biosonar target context. I found that bats use sonar sound grouping to help localize moving targets in azimuth, not just depth, and that biosonar strategies change in complex, multi-faceted ways with the introduction of acoustic clutter. Finally, in Experiment 3 I used a non-invasive EEG recording method to record auditory evoked potentials in unanesthetized bats. By combining this method with an auditory oddball paradigm, I was able to measure changes in the bats’ auditory response in response to perceptually salient changes in echolocation stimuli.
Notes:: Thesis (Ph. D.)--Brown University, 2023

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Citation

Tuninetti, Amaro, "Investigating spatial attention in echolocating bats" (2023). Cognitive, Linguistic, and Psychological Sciences Theses and Dissertations. Brown Digital Repository. Brown University Library. https://repository.library.brown.edu/studio/item/bdr:wqe7az7u/

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Cognitive, Linguistic, and Psychological Sciences Theses and Dissertations

Theses and Dissertations for the Cognitive, Linguistic, and Psychological Sciences department.
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