University of Maryland >> Auditory Neuroethology Lab >> Ben Falk

Ben Falk graduate student bfalk AT umd DOT edu (301)405.0374 Neuroscience and Cognitive Science Program Department of Psychology University of Maryland College Park, MD 20742

Interests

• Echolocation and object recognition
• Sensorimotor integration
• Flight kinematics

Projects

• Texture Discrimination using Echolocation
  Echolocating bats navigate obstacles and identify prey using sonar by emitting high frequency vocalizations and listening to the returning echoes. As an undergraduate we were interested in determining the extent that bats identify objects of different texture using echolocation. For my undergraduate honors thesis, I worked with another undergraduate, Tameeka Williams, to train bats Eptesicus fuscus to hit a smooth object over different textured objects. We recorded the successful discrimination performance of the bat with different textured objects. We also recorded the sonar vocalizations, the sonar beam aim, and the three dimensional trajectory of the bat during discrimination. This allowed us to reconstruct each trial, determining how the bat was able to successfully discriminate the objects using echolocation. We found that bats sequentially inspected each target, adjusting the timing and aiming of their vocalizations to separate the returning echoes from each object. You can find video animations of trials here. We also presented posters detailing this work at ARO and SFN in 2005 - pdf's available below.
• Groove Discrimination using Echolocation
  Our studies of texture discrimination indicated that bats likely combine multiple echo returns from each target to successfully identify them. In this study we fabricated small spheres with grooves drilled either horizontally or vertically. We trained the bat to hit the horizontal grooved object. The reason for the fabricated grooves was to give the bat an acoustic cue for discrimination. However, the groove orientation can only be determined by the bat through successive pings as it moves around the objects. This allowed us to dermine whether the bat was identifying the objects using only a single echo return or by combining information from successive vocalizations. Bats were successfully trained in the task. The work was presented at the International Congress of Neuroethology in 2007 - pdf available below.
• Bat Wing Hairs
  Small sensory hairs are found on the surface of the wing of all bat species investigated to date. We believe that these hairs may have a role in flight control and prey capture. I am currently working on determing the role of these hairs by comparing flight performance before and after wing hair removal (with over the counter depilatory cream). We have found that flight behavior changes with hair removal, and we presented some of this work at the Society for Neuroscience meeting and the North American Society for Bat Research in 2008 - abstract and pdf available below.
• Flight Control
  

Education

PhD 2007-2012 (expected)	University of Maryland, College Park, MD, USA	Neuroscience and Cognitive Science
Bachelor of Science 2001-2005	University of Maryland, College Park, MD, USA	Psychology Department with Honors Thesis on the discrimination of texture by echolocating bats

Publications

Papers

• Yossi Yovel, Ben Falk, Cynthia F. Moss, Nachum Ulanovsky (2011). Active Control of Acoustic Field-of-View in a Biosonar System PLOS Biology. doi:10.1371/journal.pbio.1001150
• Sterbing-D'Angelo, S., Chadha, M., Chiu, C., Falk, B., Xian, W., Barcelo, J., Zook, J. M., Moss, C. F. (2011). Bat wing sensors support flight control. Proceedings of the National Academy of Sciences. doi:10.1073/pnas.1018740108
• Falk, B., Williams, T., Aytekin, M., & Moss, C. F. (2011). Adaptive behavior for texture discrimination by the free-flying big brown bat, Eptesicus fuscus. Journal of Comparative Physiology. A, Neuroethology, Sensory, Neural, and Behavioral Physiology. doi:10.1007/s00359-010-0621-6
• Yovel, Y., Falk, B., Moss, C. F., & Ulanovsky, N. (2010). Optimal Localization by Pointing Off Axis. Science, 327(5966), 701-704. doi:10.1126/science.1183310

Poster Presentations

• Falk, B., Yovel, Y., Livingston, S., & Moss, C. F. (2011). Comparison of Sonar Behavior During Landing in Laryngeal and Lingual Echolocating Bats, Eptesicus fuscus and Rousettus aegyptiacus. Presented at the 3rd Symposium on Acoustic Communication by Animals, Cornell University. [pdf]
• Falk, B., Jakobsen, L., Varadarajan, D., & Moss, C. F. (2011). Adaptive sonar and flight behavior of the echolocating bat, Eptesicus fuscus. Presented at the Association for Research in Otolaryngology, Baltimore, MD. [pdf]
• Falk, B., Aytekin, M., & Moss, C. F. (2010). Texture Discrimination by Echolocation in the Big Brown Bat. Presented at the Acoustical Society of America. [abstract] [pdf]
• Falk, B., Zook, J. M., Sterbing-D'Angelo, & Moss, C. F. (2008). Wing Surface Tactile Receptors: Electron Microscopy and Flight Behavior. Presented at the North American Society for Bat Research. [pdf]
• Zook, J. M., Falk, B., Sterbing-D'Angelo, S. J., & Moss, C. F. (2008). Separate contributions of dorsal and ventral wing-surface tactile receptors to bat flight behavior. Presented at the Society for Neuroscience. [abstract]
• Falk, B., & Moss, C. F. (2007). Motion Dependent Object Representation in Eptesicus fuscus. Presented at the International Congress of Neuroethology. [pdf]
• Falk, B., Williams, T., Aytekin, M., Ghose, K., & Moss, C. F. (2005). Texture discrimination by echolocation: acoustics and behavior. Presented at the Society for Neuroscience [abstract] [pdf]
• Falk, B., Williams, T., Aytekin, M., Ghose, K., & Moss, C. F. (2005). Object Discrimination in the Flying Bat, Eptesicus Fuscus. Presented at the Association for Research in Otolaryngology [abstract] [pdf]

Support

This work was supported in part by training grant DC-00046 from the National Institute of Deafness and Communicative Disorders of the National Institutes of Health.

University of Maryland >> Auditory Neuroethology Lab >> Ben Falk