Saprykin V A, Korolev V I, Dmitrieva E S, Fedenko M S, Borisova E D
Fiziol Zh SSSR Im I M Sechenova. 1977 Aug;63(8):1083-7.
The echo-location characteristics were studied in dolphins with the aid of transformation of stimuli not altering the reception characteristics in analysing systems. The dolphin locator was shown to be able to single out a class of equivalent in respect to certain transformations echo-signals. The probability of the target recognition is invariable in respect to transformations of homothetic type and module transformations, i.e. the principle of invariability spreads over the work of dolphin's auditory analyser in active regimen too.
借助于在分析系统中不改变接收特性的刺激变换，对海豚的回声定位特性进行了研究。结果表明，海豚的定位器能够区分出一类在某些变换方面等效的回声信号。目标识别的概率对于相似类型变换和模变换而言是不变的，也就是说，不变性原理也适用于海豚听觉分析器在主动模式下的工作。
