在背景干扰条件下大棕蝠对静止及移动目标的探测

采用“双选”的心理物理学方法 ,研究了训练后的大棕蝠 (Eptesicusfuscus)在背景干扰的条件下探测半圆形目标的能力。半圆形目标系以静止、旋转、摆动或不同组合的旋转与摆动呈现于蝙蝠。在测试室 ,蝙蝠-目标间距从 3 0cm开始 ,依次递增 10cm直至 110cm为止。当蝙蝠 -目标间距小于 80cm时 ,目标回声的强度总是大于背景干扰声。由旋转目标反射的回声强度则依正弦波调制。结果发现 :蝙蝠对目标的正确探测率随蝙蝠 -目标间距的增加而降低 ;在每一特定间距 ,对移动目标的正确探测率均高于对静止目标的正确探测率

Detection of stationary and moving targets under clutter interference by the big brown bat Eptesicus fuscus

Using a two-choice psychophysical procedure, we studied the detection of a semicircular target under background noise interference by trained Eptesi cus fuscus. The target was presented under conditions of either stationary, r evolving, oscillating or different combinations of oscillation and revolution at a bat-to-target distance of 10 cm increments from 30 to 110 cm inside a test ch amber. During the test, the amplitude of the target echo was always larger than that of the background noise at a bat-to-target distance up to 80 cm. The ec ho amplitude from a revolving target was sinusoidally modulated between a maximal and minimal value. The percent correct response of target detection by these ba ts decreased with increasing bat-to-target distance. However, the percent cor re ct response was always higher for a moving target than for a stationary one at e ach bat-to-target distance tested .