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A Functional Role of FM Sweep Rate of Biosonar in Echolocation of Bat

  • Kazuhisa Fujita
  • Eigo Kamata
  • Satoru Inoue
  • Yoshiki Kashimori
  • Takeshi Kambara
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3316)

Abstract

Most species of bats making echolocation use frequency modulated(FM) ultrasonic pulses to measure the distance to targets.These bats detect with a high accuracy the arrival time differences between emitted pulses and their echoes generated by targets. In order to clarify the neural mechanism for echolocation, we present neural model of inferior colliculus(IC). The bats increase the downward frequency sweep rate of emitted FM pulse as they approach the target. The functional role of this modulation of sweep rate is not yet clear. In order to investigate the role, we calculated the response properties of our models of IC changing the target distance and the sweep rate. We found based on the simulations that the distance of a target in various ranges may be encoded the most clearly into the activity pattern of delay time map network in IC, when bats adopt the observed FM sweep rate for each range of target distance.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2004

Authors and Affiliations

  • Kazuhisa Fujita
    • 1
  • Eigo Kamata
    • 1
  • Satoru Inoue
    • 2
  • Yoshiki Kashimori
    • 1
    • 3
  • Takeshi Kambara
    • 1
    • 3
  1. 1.Department of Information Network Science, School of Information SystemsUniversity of Electro-CommunicationsChofu, TokyoJapan
  2. 2.Department of Computer ScienceFaculty of Engineering, Saitama Institute of TechnologyOkabe, SaitamaJapan
  3. 3.Department of Applied Physics and ChemistryUniversity of Electro-CommunicationsChofu, TokyoJapan

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