Bats Use Echo Harmonic Structure to Distinguish Their Targets from Background Clutter
Bats Use Echo Harmonic Structure to Distinguish Their Targets from Background Clutter
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DOI：
10.1126/science.1202065
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发表时间：
2011-07-29
期刊：
影响因子：
56.9
通讯作者：
Zorikov, Tengiz V.
中科院分区：
文献类型：
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作者：
Bates, Mary E.;Simmons, James A.;Zorikov, Tengiz V.
当大型棕色蝙蝠在复杂的环境中飞行时，来自位于声纳波束两侧的不相关物体（杂波）的回声会掩盖对位于前方的相关物体（目标）的感知，从而导致“盲点”。“由于第二谐波比第一谐波更弱地向两侧发射，这些杂波回波具有较弱的第二谐波。在心理物理学实验中，我们发现，电子错位的第一和第二谐波回波（模仿相应的神经反应的失调杂波回波谐波）扰乱蝙蝠的回声延迟感知，但也防止杂波掩蔽。电子抵消谐波，重新调整他们的神经反应恢复延迟感知，但也杂波干扰。因此，蝙蝠利用谐波来区分杂波回波与目标回波，牺牲延迟敏锐度来抑制掩蔽。
When echolocating big brown bats fly in complex surroundings, echoes arriving from irrelevant objects (clutter) located to the sides of their sonar beam can mask perception of relevant objects located to the front (targets), causing "blind spots." Because the second harmonic is beamed more weakly to the sides than the first harmonic, these clutter echoes have a weaker second harmonic. In psychophysical experiments, we found that electronically misaligning first and second harmonics in echoes (to mimic the misalignment of corresponding neural responses to harmonics in clutter echoes) disrupts the bat's echo-delay perception but also prevents clutter masking. Electronically offsetting harmonics to realign their neural responses restores delay perception but also clutter interference. Thus, bats exploit harmonics to distinguish clutter echoes from target echoes, sacrificing delay acuity to suppress masking.